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Montero-Jimenez, Marjorie, Francisco L. Amante, Gonzalo E. Fenoy, Juliana Scotto, Omar Azzaroni i Waldemar A. Marmisolle. "PEDOT-Polyamine-Based Organic Electrochemical Transistors for Monitoring Protein Binding". Biosensors 13, nr 2 (17.02.2023): 288. http://dx.doi.org/10.3390/bios13020288.
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The fabrication of efficient organic electrochemical transistors (OECTs)-based biosensors requires the design of biocompatible interfaces for the immobilization of biorecognition elements, as well as the development of robust channel materials to enable the transduction of the biochemical event into a reliable electrical signal. In this work, PEDOT-polyamine blends are shown as versatile organic films that can act as both highly conducting channels of the transistors and non-denaturing platforms for the construction of the biomolecular architectures that operate as sensing surfaces. To achieve this goal, we synthesized and characterized films of PEDOT and polyallylamine hydrochloride (PAH) and employed them as conducting channels in the construction of OECTs. Next, we studied the response of the obtained devices to protein adsorption, using glucose oxidase (GOx) as a model system, through two different strategies: The direct electrostatic adsorption of GOx on the PEDOT-PAH film and the specific recognition of the protein by a lectin attached to the surface. Firstly, we used surface plasmon resonance to monitor the adsorption of the proteins and the stability of the assemblies on PEDOT-PAH films. Then, we monitored the same processes with the OECT showing the capability of the device to perform the detection of the protein binding process in real time. In addition, the sensing mechanisms enabling the monitoring of the adsorption process with the OECTs for the two strategies are discussed.
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Espinosa, Francisco, Manuel Uhlig i Ricardo Garcia. "Molecular Recognition by Silicon Nanowire Field-Effect Transistor and Single-Molecule Force Spectroscopy". Micromachines 13, nr 1 (8.01.2022): 97. http://dx.doi.org/10.3390/mi13010097.
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Silicon nanowire (SiNW) field-effect transistors (FETs) have been developed as very sensitive and label-free biomolecular sensors. The detection principle operating in a SiNW biosensor is indirect. The biomolecules are detected by measuring the changes in the current through the transistor. Those changes are produced by the electrical field created by the biomolecule. Here, we have combined nanolithography, chemical functionalization, electrical measurements and molecular recognition methods to correlate the current measured by the SiNW transistor with the presence of specific molecular recognition events on the surface of the SiNW. Oxidation scanning probe lithography (o-SPL) was applied to fabricate sub-12 nm SiNW field-effect transistors. The devices were applied to detect very small concentrations of proteins (500 pM). Atomic force microscopy (AFM) single-molecule force spectroscopy (SMFS) experiments allowed the identification of the protein adsorption sites on the surface of the nanowire. We detected specific interactions between the biotin-functionalized AFM tip and individual avidin molecules adsorbed to the SiNW. The measurements confirmed that electrical current changes measured by the device were associated with the deposition of avidin molecules.
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Cote, Sebastien, Delphine Bouilly i Normand Mousseau. "The Electrostatic Gating of Carbon Nanotube Field-Effect Biosensors Characterized at the Molecular Scale Using Simulations". ECS Meeting Abstracts MA2022-01, nr 9 (7.07.2022): 721. http://dx.doi.org/10.1149/ma2022-019721mtgabs.
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Carbon nanotube field-effect biosensors (CNT-bioFETs) are ultraminiaturized devices that can be used to measure single-molecule kinetics of biomolecules on time scales going from a few microseconds to several minutes, as demonstrated for nucleic acid hybridization [1] and folding [2] as well as for enzyme function [3]. Experiments indicate that the sensitivity of CNT-bioFETs originates from the interplay between the nanotube’s conductance, which is monitored by the device, and the electrostatic potential generated by the biomolecule under investigation, which is localized on the nanotube [4,5]. The measured conductance exhibits characteristic transitions between two levels (or more) as a function of time, as the biomolecule folds or performs its function. Yet, the origin of this electrostatic gating of the carbon nanotube by a single biomolecule is not well understood at the molecular scale. To bridge this gap, we employ molecular dynamics (MD) and Hamiltonian replica exchange (HREX) simulations to unveil: (1) the interactions between the biomolecule and the nanotube to which it is attached in the device and (2) the electrostatic potential on the nanotube as the state of the biomolecule changes. We address these questions by considering three prototypical cases: the function of the Lysozyme protein, the hybridization of 10-nt DNA sequence and the folding of a DNA G-quadruplex, which were previously characterized using CNT-bioFETs [1-5]. Our simulations show that the lysozyme, the 10-nt DNA sequence and the DNA G-quadruplex interact differently with the nanotube to which they are attached. Consequently, the electrostatic potential (ESP) that they generate on the nanotube is very sensitive to the type and state of the biomolecule. When compared to experiment, the ESP distribution for the with-ligand and without-ligand states of the Lysozyme protein are in line with the measured two-level conductance by CNT-bioFETs. For the DNAs, however, the ESP distribution for their different states does not agree with the measured two-level conductance. Experiments imply that the DNA strand is not interacting with the nanotube, which is not what our simulations suggest. The reason for this apparent conflict could arise from the impact of the external electric field imposed by the gate electrode in CNT-bioFETs on highly charged systems such as DNAs, as supported by our recent simulations. The significance of this work is twofold. First, it contributes to a better understanding of the inner working of carbon nanotube field-effect biosensors, which is crucially needed to support the development of these promising devices in the lab. Second, it provides the structural ensemble of the biomolecules and their interactions with the nanotube in these devices, which can serve as a starting point for a finer characterization of their effect on the carbon nanotube’s conductance at the ab initio level. [1] S. Sorgenfrei et al. Nat Nanotechnol, 2011, 6, 126-132. [2] D. Bouilly et al. Nano Lett, 2016, 16, 4679-4685. [3] Y. Choi et al. Science, 2012, 335, 319-324. [4] S. Sorgenfrei et al. Nano Lett, 2011, 11, 3739-3743. [5] Y. Choi et al. Nano Lett, 2013, 13, 625-631.
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Samarentsis, Anastasios G., Alexandros K. Pantazis, Achilleas Tsortos, Jean-Michel Friedt i Electra Gizeli. "Hybrid Sensor Device for Simultaneous Surface Plasmon Resonance and Surface Acoustic Wave Measurements". Sensors 20, nr 21 (29.10.2020): 6177. http://dx.doi.org/10.3390/s20216177.
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Surface plasmon resonance (SPR) and Love wave (LW) surface acoustic wave (SAW) sensors have been established as reliable biosensing technologies for label-free, real-time monitoring of biomolecular interactions. This work reports the development of a combined SPR/LW-SAW platform to facilitate simultaneous optical and acoustic measurements for the investigation of biomolecules binding on a single surface. The system’s output provides recordings of two acoustic parameters, phase and amplitude of a Love wave, synchronized with SPR readings. We present the design and manufacturing of a novel experimental set-up employing, in addition to the SPR/LW-SAW device, a 3D-printed plastic holder combined with a PDMS microfluidic cell so that the platform can be used in a flow-through mode. The system was evaluated in a systematic study of the optical and acoustic responses for different surface perturbations, i.e., rigid mass loading (Au deposition), pure viscous loading (glycerol and sucrose solutions) and protein adsorption (BSA). Our results provide the theoretical and experimental basis for future application of the combined system to other biochemical and biophysical studies.
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ZHANG, YONG. "INTEGRATION OF NANOPARTICLES WITH PROTEIN MICROARRAYS". International Journal of Nanoscience 05, nr 02n03 (kwiecień 2006): 189–94. http://dx.doi.org/10.1142/s0219581x0600422x.
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A variety of DNA, protein or cell microarray devices and systems have been developed and commercialized. In addition to the biomolecule related analysis, they are also being used for pharmacogenomic research, infectious and genetic disease and cancer diagnostics, and proteomic and cellular analysis.1 Currently, microarray is fabricated on a planar surface; this limits the amount of biomolecules that can be bounded on the surface. In this work, a planar protein microarray chip with nonplanar spot surface was fabricated to enhance the chip performance. A nonplanar spot surface was created by first coating the silica nanoparticles with albumin and depositing them into the patterned microwells. The curve surfaces of the nanoparticles increase the surface area for immobilization of proteins, which helps to enhance the detection sensitivity of the chip. Using this technique, proteins are immobilized onto the nanoparticles before they are deposited onto the chip, and therefore the method of protein immobilization can be customized at each spot. Furthermore, a nonplanar surface promotes the retention of native protein structure better than planar surface.2 The technique developed can be used to produce different types of microarrays, such as DNA, protein and antibody microarrays.
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Firek, Piotr, Michal Cichomski, Michal Waskiewicz, Ireneusz Piwoński i Aneta Kisielewska. "ISFET structures with chemically modified membrane for bovine serum albumin detection". Circuit World 44, nr 1 (5.02.2018): 45–50. http://dx.doi.org/10.1108/cw-10-2017-0061.
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Purpose The purpose of this paper is to present possibility of fast and certain identification of bovine serum albumin (BSA) by means of ion-sensitive field effect transistor (ISFET) structures. Because BSA can cause allergic reactions in humans, it is one of reasons for development of sensitive sensors to detect residual BSA. BSA is commonly used in biochemistry and molecular biology in laboratory experiments. Therefore, to better understand the mechanism of signal transduction in simulated biological environment and to elucidate the role of adsorption of biomolecules in the generation of a signal at the interface with biological systems, the measurements of ISFET current response in the presence of BSA as a reference protein molecule were performed. Design/methodology/approach To fabricate transistors, silicon technology was used. The ISFET structures were coupled to specially designed double-side printed circuit board holder. After modification of the field effect transistor (FET) device with 3-aminopropyltriethoxysilane (APTES), a sensor with high sensitivity toward reference biomolecules was obtained. The current–voltage (I-V) characteristics of structures with and without gate modification were measured. Keithley SMU 236/237/238 measurement set was used. Deionized water solution and 0.05 per cent BSA were used. Findings In this research, a method of preparation of a biosensor based on a FET was developed. Sensitivity of APTES-modified FET device toward BSA as a biomolecule was investigated. I-V relationships of FET devices (with and without modification), being the effect of the interactions with the solution containing 0.05 per cent BSA, were measured and compared to the measurements performed for solutions without BSA. Originality value Compared to SiO2-containing ISFETs without modification or other different dielectrics, the application of APTES as the part of the membrane induced significant increase in their sensitivity to BSA.
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Kasetsirikul, Surasak, Kimberley Clack, Muhammad J. A. Shiddiky i Nam-Trung Nguyen. "Rapid, Simple and Inexpensive Fabrication of Paper-Based Analytical Devices by Parafilm® Hot Pressing". Micromachines 13, nr 1 (29.12.2021): 48. http://dx.doi.org/10.3390/mi13010048.
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Paper-based analytical devices have been substantially developed in recent decades. Many fabrication techniques for paper-based analytical devices have been demonstrated and reported. Herein, we report a relatively rapid, simple, and inexpensive method for fabricating paper-based analytical devices using parafilm hot pressing. We studied and optimized the effect of the key fabrication parameters, namely pressure, temperature, and pressing time. We discerned the optimal conditions, including a pressure of 3.8 MPa, temperature of 80 °C, and 3 min of pressing time, with the smallest hydrophobic barrier size (821 µm) being governed by laminate mask and parafilm dispersal from pressure and heat. Physical and biochemical properties were evaluated to substantiate the paper functionality for analytical devices. The wicking speed in the fabricated paper strips was slightly lower than that of non-processed paper, resulting from a reduced paper pore size after hot pressing. A colorimetric immunological assay was performed to demonstrate the protein binding capacity of the paper-based device after exposure to pressure and heat from the fabrication. Moreover, mixing in a two-dimensional paper-based device and flowing in a three-dimensional counterpart were thoroughly investigated, demonstrating that the paper devices from this fabrication process are potentially applicable as analytical devices for biomolecule detection. Fast, easy, and inexpensive parafilm hot press fabrication presents an opportunity for researchers to develop paper-based analytical devices in resource-limited environments.
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Ohshiro, Takahito, Yuki Komoto i Masateru Taniguchi. "Single-Molecule Counting of Nucleotide by Electrophoresis with Nanochannel-Integrated Nano-Gap Devices". Micromachines 11, nr 11 (31.10.2020): 982. http://dx.doi.org/10.3390/mi11110982.
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We utilized electrophoresis to control the fluidity of sample biomolecules in sample aqueous solutions inside the nanochannel for single-molecule detection by using a nanochannel-integrated nanogap electrode, which is composed of a nano-gap sensing electrode, nanochannel, and tapered focusing channel. In order to suppress electro-osmotic flow and thermal convection inside this nanochannel, we optimized the reduction ratios of the tapered focusing channel, and the ratio of inlet 10 μm to outlet 0.5 μm was found to be high performance of electrophoresis with lower concentration of 0.05 × TBE (Tris/Borate/EDTA) buffer containing a surfactant of 0.1 w/v% polyvinylpyrrolidone (PVP). Under the optimized conditions, single-molecule electrical measurement of deoxyguanosine monophosphate (dGMP) was performed and it was found that the throughput was significantly improved by nearly an order of magnitude compared to that without electrophoresis. In addition, it was also found that the long-duration signals that could interfere with discrimination were significantly reduced. This is because the strong electrophoresis flow inside the nanochannels prevents the molecules’ adsorption near the electrodes. This single-molecule electrical measurement with nanochannel-integrated nano-gap electrodes by electrophoresis significantly improved the throughput of signal detection and identification accuracy.
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Bhushan, Bharat, Kwang Joo Kwak, Samit Gupta i Stephen C. Lee. "Nanoscale adhesion, friction and wear studies of biomolecules on silane polymer-coated silica and alumina-based surfaces". Journal of The Royal Society Interface 6, nr 37 (4.11.2008): 719–33. http://dx.doi.org/10.1098/rsif.2008.0398.
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Proteins on biomicroelectromechanical systems (BioMEMS) confer specific molecular functionalities. In planar FET sensors (field-effect transistors, a class of devices whose protein-sensing capabilities we demonstrated in physiological buffers), interfacial proteins are analyte receptors, determining sensor molecular recognition specificity. Receptors are bound to the FET through a polymeric interface, and gross disruption of interfaces that removes a large percentage of receptors or inactivates large fractions of them diminishes sensor sensitivity. Sensitivity is also determined by the distance between the bound analyte and the semiconductor. Consequently, differential properties of surface polymers are design parameters for FET sensors. We compare thickness, surface roughness, adhesion, friction and wear properties of silane polymer layers bound to oxides (SiO 2 and Al 2 O 3 , as on AlGaN HFETs). We compare those properties of the film–substrate pairs after an additional deposition of biotin and streptavidin. Adhesion between protein and device and interfacial friction properties affect FET reliability because these parameters affect wear resistance of interfaces to abrasive insult in vivo . Adhesion/friction determines the extent of stickage between the interface and tissue and interfacial resistance to mechanical damage. We document systematic, consistent differences in thickness and wear resistance of silane films that can be correlated with film chemistry and deposition procedures, providing guidance for rational interfacial design for planar AlGaN HFET sensors.
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Kasoju, Naresh, Julian George, Hua Ye i Zhanfeng Cui. "Sacrificial Core-Based Electrospinning: A Facile and Versatile Approach to Fabricate Devices for Potential Cell and Tissue Encapsulation Applications". Nanomaterials 8, nr 10 (21.10.2018): 863. http://dx.doi.org/10.3390/nano8100863.
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Electrospinning uses an electric field to produce fine fibers of nano and micron scale diameters from polymer solutions. Despite innovation in jet initiation, jet path control and fiber collection, it is common to only fabricate planar and tubular-shaped electrospun products. For applications that encapsulate cells and tissues inside a porous container, it is useful to develop biocompatible hollow core-containing devices. To this end, by introducing a 3D-printed framework containing a sodium chloride pellet (sacrificial core) as the collector and through post-electrospinning dissolution of the sacrificial core, we demonstrate that hollow core containing polyamide 66 (nylon 66) devices can be easily fabricated for use as cell encapsulation systems. ATR-FTIR and TG/DTA studies were used to verify that the bulk properties of the electrospun device were not altered by contact with the salt pellet during fiber collection. Protein diffusion investigations demonstrated that the capsule allowed free diffusion of model biomolecules (insulin, albumin and Ig G). Cell encapsulation studies with model cell types (fibroblasts and lymphocytes) revealed that the capsule supports the viability of encapsulated cells inside the capsule whilst compartmentalizing immune cells outside of the capsule. Taken together, the use of a salt pellet as a sacrificial core within a 3D printed framework to support fiber collection, as well as the ability to easily remove this core using aqueous dissolution, results in a biocompatible device that can be tailored for use in cell and tissue encapsulation applications.
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Lee, Ju Seok, Joon Jin Song, Russell Deaton i Jin-Woo Kim. "Assessing the Detection Capacity of Microarrays as Bio/Nanosensing Platforms". BioMed Research International 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/310461.
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Microarray is one of the most powerful detection systems with multiplexing and high throughput capability. It has significant potential as a versatile biosensing platform for environmental monitoring, pathogen detection, medical therapeutics, and drug screening to name a few. To date, however, microarray applications are still limited to preliminary screening of genome-scale transcription profiling or gene ontology analysis. Expanding the utility of microarrays as a detection tool for various biological and biomedical applications requires information about performance such as the limits of detection and quantification, which are considered as an essential information to decide the detection sensitivity of sensing devices. Here we present a calibration design that integrates detection limit theory and linear dynamic range to obtain a performance index of microarray detection platform using oligonucleotide arrays as a model system. Two different types of limits of detection and quantification are proposed by the prediction or tolerance interval for two common cyanine fluorescence dyes, Cy3 and Cy5. Besides oligonucleotide, the proposed method can be generalized to other microarray formats with various biomolecules such as complementary DNA, protein, peptide, carbohydrate, tissue, or other small biomolecules. Also, it can be easily applied to other fluorescence dyes for further dye chemistry improvement.
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Roth, Shira, Michael Margulis i Amos Danielli. "Recent Advances in Rapid and Highly Sensitive Detection of Proteins and Specific DNA Sequences Using a Magnetic Modulation Biosensing System". Sensors 22, nr 12 (14.06.2022): 4497. http://dx.doi.org/10.3390/s22124497.
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In early disease stages, biomolecules of interest exist in very low concentrations, presenting a significant challenge for analytical devices and methods. Here, we provide a comprehensive overview of an innovative optical biosensing technology, termed magnetic modulation biosensing (MMB), its biomedical applications, and its ongoing development. In MMB, magnetic beads are attached to fluorescently labeled target molecules. A controlled magnetic force aggregates the magnetic beads and transports them in and out of an excitation laser beam, generating a periodic fluorescent signal that is detected and demodulated. MMB applications include rapid and highly sensitive detection of specific nucleic acid sequences, antibodies, proteins, and protein interactions. Compared with other established analytical methodologies, MMB provides improved sensitivity, shorter processing time, and simpler protocols.
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Jia, Xiao, Yang Liu, Yanmei Yang, Chao Zhang, Yuanyuan Qu, Yong-Qiang Li, Xiangdong Liu i Weifeng Li. "Exploring the biotoxicity of carbon boride nanosheets (BC3) based on the villin headpiece protein model". Journal of Physics D: Applied Physics 55, nr 17 (3.02.2022): 175403. http://dx.doi.org/10.1088/1361-6463/ac4d4c.
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Abstract The recently synthesized single-layer carbon boride (BC3), has been explored for biomedical applications. However, the interaction between BC3 and biomolecules needs to be further explored to evaluate its potential toxicity to biological systems. Here, using the villin headpiece (HP35) as a representative protein model, the binding behavior of proteins to BC3 and the structure evolution of proteins were studied by molecular dynamics simulation. Our data revealed that HP35 can quickly load and form stable binding to BC3 surface. The BC3 caused moderate destruction of the HP35 by destroying its native hydrogen bonds and unwinding its helices. The BC3/HP35 interaction strength is linearly correlated with the contact number between BC3 and HP35. HP35 forms binds to BC3 mainly through van der Waals interactions and π-π stacking. Compared to graphene, the polarized nature of BC3 can slightly strengthen the binding between BC3 and HP35. BC3 still faces the problem of potential cytotoxicity to biological system. These findings shed light on the biological effects of BC3 at the molecular level and guide the future application of BC3-based devices in biomedicine.
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Demirhan, Alper, Ece Eksin, Yalin Kilic i Arzum Erdem. "Low-Cost High-Resolution Potentiostat for Electrochemical Detection of Nucleic Acids and Biomolecular Interactions". Micromachines 13, nr 10 (27.09.2022): 1610. http://dx.doi.org/10.3390/mi13101610.
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A handheld USB-powered instrument developed for the electrochemical detection of nucleic acids and biomolecular interactions is presented. The proposed instrument is capable of scanning ± 2.25 V while measuring currents up to ±10 mA, with a minimum current resolution of 6.87 pA. Therefore, it is suitable for nucleic acid sensors, which have high background currents. A low-cost microcontroller with an on-chip 16-bit analog-to-digital converter, 12-bit digital-to-analog converter, and a built-in USB controller were used to miniaturize the system. The offset voltages and gain errors of the analog peripherals were calibrated to obtain a superior performance. Thus, a similar performance to those of the market-leader potentiostats was achieved, but at a fraction of their cost and size. The performance of the application of this proposed architecture was tested successfully and was found to be similar to a leading commercial device through a clinical application in the aspects of the detection of nucleic acids, such as calf thymus ssDNA and dsDNA, and their interactions with a protein (BSA) by using single-use graphite electrodes in combination with the differential pulse voltammetry technique.
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Sitkov, Nikita, Andrey Ryabko, Alexey Kolobov, Alexsandr Maximov, Vyacheslav Moshnikov, Stanislav Pshenichnyuk, Alexei Komolov, Andrey Aleshin i Tatiana Zimina. "Impedimetric Biosensor Coated with Zinc Oxide Nanorods Synthesized by a Modification of the Hydrothermal Method for Antibody Detection". Chemosensors 11, nr 1 (13.01.2023): 66. http://dx.doi.org/10.3390/chemosensors11010066.
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Impedimetric biosensors are used for detecting a wide range of analytes. The detection principle is a perspective for the development of new types of analytical devices for biomolecular diagnosis of diseases. Of particular interest are biosensors with very high sensitivities, capable of detecting trace amounts of biomarkers or drugs in biological fluids. Impedimetric biosensors possess a potential for increased sensitivity, since their electrodes can be modified with nanostructured materials, in particular zinc oxide. In this work, a miniature biosensor with an array of zinc oxide nanorods synthesized by the hydrothermal method has been created. Protein A was immobilized on the resulting structure, which was previously tested for binding to omalizumab by capillary electrophoresis. Using impedance spectroscopy, it was possible to detect the binding of omalizumab at concentrations down to 5 pg/mL. The resulting structures are suitable for creating reusable biosensor systems, since ZnO-coated electrodes are easily cleaned by photocatalytic decomposition of the bound molecules. The biosensor is promising for use in Point-of-Care systems designed for fast, multimodal detection of molecular markers of a wide range of diseases.
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Wan Ahamad, Wan Mohd Azwady, Dzaraini Kamarun, Mohd Kamil Abd Rahman i Mohamad Shukri Kamarudin. "Modular Surface Plasmon Resonance (SPR) Biosensor Based on Wavelength Modulation". Advanced Materials Research 1107 (czerwiec 2015): 699–705. http://dx.doi.org/10.4028/www.scientific.net/amr.1107.699.
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This paper deals with a new invention of modular surface plasmon resonance (SPR) biosensor device based on wavelength modulation wherein the angle of incidence of the light source is fixed and the shift in wavelength at resonance is monitored. This device is capable of detecting biomolecular binding interactions of different species such as protein and viruses based on changes in the refractive index of the dielectric environment. White light source mounted with a polarizer is used to excite plasmons on the sensor surface which is thin gold film of ~21 μm thickness coated on BK-7 glass. A variable angle reflection sampling system (VARSS) device from Ocean Optics was modified to incorporate the transducer components and sampling accessories. SPR was observed at the angle of incidence of the light fixed at 29°. At this point, plasmon evanescent wave coupling occurred with highest loss of light intensity. HR4000-UV-NIR photodetector is used to observe the change in resonance wavelength when the dielectric environment around the surface of the transducer was changed. Two liquid samples; water (n=1.33) and ethylene glycol (n=1.43) was introduced onto the sensor surface to model changes in wavelength resonance with difference in refractive index of dielectric environment. It was observed that the resonance wavelength for water and ethylene glycol are 590.10 nm and 594.23 nm respectively when reference to air (n=1.00) indicating the workability of the device.
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Wibowo, Nur Aji, Harsojo i Edi Suharyadi. "Prospect of core-shell Fe3O4@Ag label integrated with spin-valve giant magnetoresistance for future point-of-care biosensor". Advances in Natural Sciences: Nanoscience and Nanotechnology 12, nr 4 (1.12.2021): 045013. http://dx.doi.org/10.1088/2043-6262/ac498e.
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Abstract Magnetic-based biosensors are the analytical instruments that convert the biological recognition into the electrical signal through the generating of the stray-field of the magnetic nanoparticles (MNPs) attached to the biomolecule target. The magnetic biosensor feature relies on the transducer and the MNPs label selection. Recently, the biosensor with a point-of-care feature is the most expected device in the nowadays medical diagnostic field. So that, a review of the recent research related to the novel integration of magnetoresistance-based transducers with MNPs for biosensor application is vital for the point-of-care diagnostic development. Hence, the basic principle of biosensors and the giant magnetoresistance (GMR) with exchange bias phenomena are introduced. Furthermore, we provide a review of the cutting edge method in GMR biosensor with spin-valve structure (SV-GMR) which is integrated to MNPs for biomolecule labelling. As review results, among the nano-sized magnetoresistance transducer, the SV-GMR has some predominance, i.e. electrical robustness and moderate magnetoresistance ratio. Meanwhile, as compared to the other proposed MNPs such as pure Fe3O4, Fe2O3, and hybrid Fe3O4-graphene, the core-shell Fe3O4@Ag is potent to be used, which offers not only moderate saturation magnetisation but also good protein affinity, antimicrobial activity, and minimal cytotoxicity. According to the sensor performance comparison, the usage of Fe3O4@Ag for biomolecule labelling in synergy with SV-GMR transducer is prospective to be developed. The Ag shell espouses the protein immobilisation to the surface of the MNPs label that improves the sensor sensitivity. Furthermore, the SV-GMR possessed two modes of the Fe3O4@Ag rapid detection, which are through the moderate voltage change and the switching field shifting. Meanwhile, the concentration increase of Fe3O4@Ag can be well quantified. Moreover, the Fe3O4@Ag/SV-GMR system had a low operating magnetic field with rapid data collection. In conclusion, the Fe3O4@Ag/SV-GMR biosensor system is believed to be applied as a real-time, portable, and cost-effective biosensor.
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Akgönüllü, Semra, Erdoğan Özgür i Adil Denizli. "Quartz Crystal Microbalance-Based Aptasensors for Medical Diagnosis". Micromachines 13, nr 9 (1.09.2022): 1441. http://dx.doi.org/10.3390/mi13091441.
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Aptamers are important materials for the specific determination of different disease-related biomarkers. Several methods have been enhanced to transform selected target molecule-specific aptamer bindings into measurable signals. A number of specific aptamer-based biosensors have been designed for potential applications in clinical diagnostics. Various methods in combination with a wide variety of nano-scale materials have been employed to develop aptamer-based biosensors to further increase sensitivity and detection limit for related target molecules. In this critical review, we highlight the advantages of aptamers as biorecognition elements in biosensors for target biomolecules. In recent years, it has been demonstrated that electrode material plays an important role in obtaining quick, label-free, simple, stable, and sensitive detection in biological analysis using piezoelectric devices. For this reason, we review the recent progress in growth of aptamer-based QCM biosensors for medical diagnoses, including virus, bacteria, cell, protein, and disease biomarker detection.
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Vogel, Viola. "Reverse Engineering: Learning from Proteins How to Enhance the Performance of Synthetic Nanosystems". MRS Bulletin 27, nr 12 (grudzień 2002): 972–78. http://dx.doi.org/10.1557/mrs2002.304.
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AbstractProteins are nature's workhorses. They enable living systems to use available energy sources and convert energy from one form into another. Understanding the underlying design principles of how proteins have evolved to fulfill the necessary functions of life can provide researchers with new insights into how to enhance the performance of synthetic nanosystems with far greater sophistication. This review summarizes the relationship between various protein functions and the underlying engineering principles of their overall structures. For example, proteins can specifically recognize other biomolecules with a selectivity and affinity several orders of magnitude superior to their synthetic counterparts. Mimicking a protein binding site with a structurally fixed synthetic analogue is insufficient, since structural changes in the active sites enhance molecular recognition and the catalytic activity of proteins. Recent data also show that protein function can be switched by stretching proteins into nonequilibrium states under physiological conditions. Schemes by which the exposure and structure of recognition sites are switched can be implemented in the design of mechanically responsive synthetic and hybrid systems. Motor proteins, finally, are the jewel in nature's crown, as they can convert one free-energy form into another to generate mechanical force. It is thus of considerable interest to integrate the chemically powered engines into synthetic materials and devices. Finally, we have to advance our ability to assemble nanocomponents into functional systems. Again, lessons can be learned from how biology solves the challenge of systems integration.
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Kontziampasis, Dimitrios, David P. Klebl, Matthew G. Iadanza, Charlotte A. Scarff, Florian Kopf, Frank Sobott, Diana C. F. Monteiro, Martin Trebbin, Stephen P. Muench i Howard D. White. "A cryo-EM grid preparation device for time-resolved structural studies". IUCrJ 6, nr 6 (5.09.2019): 1024–31. http://dx.doi.org/10.1107/s2052252519011345.
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Structural biology generally provides static snapshots of protein conformations that can provide information on the functional mechanisms of biological systems. Time-resolved structural biology provides a means to visualize, at near-atomic resolution, the dynamic conformational changes that macromolecules undergo as they function. X-ray free-electron-laser technology has provided a powerful tool to study enzyme mechanisms at atomic resolution, typically in the femtosecond to picosecond timeframe. Complementary to this, recent advances in the resolution obtainable by electron microscopy and the broad range of samples that can be studied make it ideally suited to time-resolved approaches in the microsecond to millisecond timeframe to study large loop and domain motions in biomolecules. Here we describe a cryo-EM grid preparation device that permits rapid mixing, voltage-assisted spraying and vitrification of samples. It is shown that the device produces grids of sufficient ice quality to enable data collection from single grids that results in a sub-4 Å reconstruction. Rapid mixing can be achieved by blot-and-spray or mix-and-spray approaches with a delay of ∼10 ms, providing greater temporal resolution than previously reported mix-and-spray approaches.
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Pancera, S. M., H. Gliemann, D. F. S. Petri i T. Schimmel. "Adsorption Behaviour of Creatine Phosphokinase onto Silicon Wafers: Comparison between Ellipsometric and Atomic Force Microscopy Data". Microscopy and Microanalysis 11, S03 (grudzień 2005): 56–60. http://dx.doi.org/10.1017/s1431927605050889.
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Protein adsorption plays a major role in a variety of important technological and biological processes [1-2] and the understanding of the fundamental factors that determine protein adsorption are imperative to the development of biocompatible materials and biotechnological devices [3-4] as for example biosensors [5]. The adsorption of proteins on surfaces is a complex process. Due to the large size and different shapes of these adsorbing particles, the interactions between the adsorbed proteins on the surface can be strongly influentiated by the fact that the particles may undergo conformational changes upon adsorption [6-7]. In a previous work the adsorption behaviour of creatine phosphokinase (CPK) onto hydrophilic (silicon wafers and amino-terminated surfaces) and hydrophobic (Polystyrene, PS, coated wafers) substrates was investigated by means of null-ellipsometry and contact angle measurements [8]. This previous ellipsometric study led to a model, where CPK adsorption takes place in four stages: (i) a diffusive one, where all the arriving biomolecules are immediately adsorbed; (ii) the arriving biomolecules might stick on the latter and afterward diffuse to the free sites on the substrate, followed by conformational changes [6-7], (iii) formation of a monolayer and (iv) continuous and irreversible adsorption. A multilayer system might be formed, as well as aggregation processes might play a role at this stage. In this work Atomic Force Microscopy (AFM) measurements under water were done in order to confirm this four steps model and to observe changes in the film topography and homogeneity along the adsorption process. The thickness of the adsorbed CPK biofilm obtained by ellipsometry was also compared with that obtained by the wet AFM method.
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Fuku, Xolile, Abdoulaye Diallo i Malik Maaza. "Nanoscaled Electrocatalytic Optically Modulated ZnO Nanoparticles through Green Process ofPunica granatumL. and Their Antibacterial Activities". International Journal of Electrochemistry 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/4682967.
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Most recently, green synthesis of metal oxide nanoparticles has become an interesting subject of the nanoscience and nanotechnology. The use of plant systems has been deemed a green route and a dependable method for nanoparticle biosynthesis, owing to its environmental friendly nature. The present work demonstrates the bioreductive green synthesis of nanosized zinc oxide (ZnO) using peel extracts of pomegranate. Highly crystalline ZnO nanoparticles (ZnO NPs) which are 5 nm in particle size were characterised by HRTEM and XRD. FT-IR spectra confirmed the presence of the biomolecules and formation of plant protein-coated ZnO NPs and also the pure ZnO NPs. Electrochemical investigation revealed the redox properties and the conductivity of the as-prepared ZnO nanoparticles. The optical band gap of ZnO NPs was calculated to be 3.48 eV which indicates that ZnO NPs can be used in metal oxide semiconductor-based devices. Further, the nanomaterials were also found to be good inhibitors of bacterial strains at both low and high concentrations of 5–10 mg mL−1.
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Serrano-De la Rosa, Laura, Abel Moreno i Mauricio Pacio. "Electro-Infiltration of Cytochrome C into a Porous Silicon Network, and Its Effect on Nucleation and Protein Crystallization—Studies of the Electrical Properties of Porous Silicon Layer-Protein Systems for Applications in Electron-Transfer Biomolecular Devices". Crystals 7, nr 7 (28.06.2017): 194. http://dx.doi.org/10.3390/cryst7070194.
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Marvi, Fahimeh, i Kian Jafari. "A label-free biomarkers detection platform relied on a bilayer long-wave infrared metamaterials BioNEMS sensor". Nanotechnology 33, nr 26 (8.04.2022): 265502. http://dx.doi.org/10.1088/1361-6528/ac5ee1.
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Abstract A novel approach based on optical Biological-Nano-Electro-Mechanical-Systems (BioNEMS) sensor is presented in this paper to provide highly sensitive and precise detection of biomolecules. The proposed BioNEMS sensor is relied on a bi-layer metamaterials structure, tuned by its wavelength. The presented biosensor consists of a BioNEMS membrane coated by Complementary Split Ring Resonators and an array of Split Ring Resonators cells on the substrate. While the immobilized bioreceptors adsorb the biomarkers (i.e. mRNA or protein), it causes a bending of the suspended membrane. This is due to the differential surface stress which is induced on the Nano-Electro-Mechanical-Systems structure. As a consequence, the coupling strength of two complementary metamaterial layers and thus the electromagnetic response of the biosensor are changed. Furthermore, the proposed device is designed and analyzed by numerical and analytical approaches in order to obtain its functional characteristics as follows: detection sensitivity of 21 967 nm/RIU, figure of merit of 327.8 RIU−1", mechanical sensitivity of 2.6 μm/Nm−1" and resonant frequency of 4.92 kHz. According to the obtained results, the functional characteristics of the proposed label-free biosensor show its high potential for highly sensitive and accurate molecule detections, disease diagnosis as well as drug delivery tests for Lab-On-Chip systems.
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Montdargent, Béatrice, i Didier Letourneur. "Toward New Biomaterials". Infection Control & Hospital Epidemiology 21, nr 6 (czerwiec 2000): 404–10. http://dx.doi.org/10.1086/501782.
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Polymers are widely used for a large range of medical devices used as biomaterials on a temporary, intermittent, and long-term basis. It is now well accepted that the initial rapid adsorption of proteins to polymeric surfaces affects the performance of these biomaterials. However, protein adsorption to a polymer surface can be modulated by an appropriate design of the interface. Extensive study has shown that these interactions can be minimized by coating with a highly hydrated layer (hydrogel), by grafting on the surface different biomolecules, or by creating domains with chemical functions (charges, hydrophilic groups). Our laboratory has investigated the latter approach over the past 2 decades, in particular the synthesis and the biological activities of polymers to improve the biocompatibility of blood-contacting devices. These soluble and insoluble polymers were obtained by chemical substitution of macromolecular chains with suitable groups able to develop specific interactions with biological components. Applied to compatibility with the blood and the immune systems, this concept has been extended to interactions of polymeric biomaterials with eukaryotic and prokaryotic cells. The design of new biomaterials with low bacterial attachment is thus under intensive study. After a brief overview of current trends in the surface modifications of biocompatible materials, we will describe how biospecific polymers can be obtained and review our recent results on the inhibition of bacterial adhesion using one type of functionalized polymer obtained by random substitution. This strategy, applied to existing or new materials, seems promising for the limitation of biomaterial-associated infections.
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Zanut, Alessandra, Alessandro Cian, Nicola Cefarin, Alessandro Pozzato i Massimo Tormen. "Nanoelectrode Arrays Fabricated by Thermal Nanoimprint Lithography for Biosensing Application". Biosensors 10, nr 8 (5.08.2020): 90. http://dx.doi.org/10.3390/bios10080090.
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Electrochemical sensors are devices capable of detecting molecules and biomolecules in solutions and determining the concentration through direct electrical measurements. These systems can be miniaturized to a size less than 1 µm through the creation of small-size arrays of nanoelectrodes (NEA), offering advantages in terms of increased sensitivity and compactness. In this work, we present the fabrication of an electrochemical platform based on an array of nanoelectrodes (NEA) and its possible use for the detection of antigens of interest. NEAs were fabricated by forming arrays of nanoholes on a thin film of polycarbonate (PC) deposited on boron-doped diamond (BDD) macroelectrodes by thermal nanoimprint lithography (TNIL), which demonstrated to be a highly reliable and reproducible process. As proof of principle, gliadin protein fragments were physisorbed on the polycarbonate surface of NEAs and detected by immuno-indirect assay using a secondary antibody labelled with horseradish peroxidase (HRP). This method allows a successful detection of gliadin, in the range of concentration of 0.5–10 μg/mL, by cyclic voltammetry taking advantage from the properties of NEAs to strongly suppress the capacitive background signal. We demonstrate that the characteristics of the TNIL technology in the fabrication of high-resolution nanostructures together with their low-cost production, may allow to scale up the production of NEAs-based electrochemical sensing platform to monitor biochemical molecules for both food and biomedical applications.
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Wu, Bingchen, Elisa Castagnola i Xinyan Tracy Cui. "Zwitterionic Polymer Coated and Aptamer Functionalized Flexible Micro-Electrode Arrays for In Vivo Cocaine Sensing and Electrophysiology". Micromachines 14, nr 2 (27.01.2023): 323. http://dx.doi.org/10.3390/mi14020323.
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The number of people aged 12 years and older using illicit drugs reached 59.3 million in 2020, among which 5.2 million are cocaine users based on the national data. In order to fully understand cocaine addiction and develop effective therapies, a tool is needed to reliably measure real-time cocaine concentration and neural activity in different regions of the brain with high spatial and temporal resolution. Integrated biochemical sensing devices based upon flexible microelectrode arrays (MEA) have emerged as a powerful tool for such purposes; however, MEAs suffer from undesired biofouling and inflammatory reactions, while those with immobilized biologic sensing elements experience additional failures due to biomolecule degradation. Aptasensors are powerful tools for building highly selective sensors for analytes that have been difficult to detect. In this work, DNA aptamer-based electrochemical cocaine sensors were integrated on flexible MEAs and protected with an antifouling zwitterionic poly (sulfobetaine methacrylate) (PSB) coating, in order to prevent sensors from biofouling and degradation by the host tissue. In vitro experiments showed that without the PSB coating, both adsorption of plasma protein albumin and exposure to DNase-1 enzyme have detrimental effects on sensor performance, decreasing signal amplitude and the sensitivity of the sensors. Albumin adsorption caused a 44.4% sensitivity loss, and DNase-1 exposure for 24 hr resulted in a 57.2% sensitivity reduction. The PSB coating successfully protected sensors from albumin fouling and DNase-1 enzyme digestion. In vivo tests showed that the PSB coated MEA aptasensors can detect repeated cocaine infusions in the brain for 3 hrs after implantation without sensitivity degradation. Additionally, the same MEAs can record electrophysiological signals at different tissue depths simultaneously. This novel flexible MEA with integrated cocaine sensors can serve as a valuable tool for understanding the mechanisms of cocaine addiction, while the PSB coating technology can be generalized to improve all implantable devices suffering from biofouling and inflammatory host responses.
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Ma, Gang, Jian Liu, Li Fu i Elsa C. Y. Yan. "Probing Water and Biomolecules at the Air—Water Interface with a Broad Bandwidth Vibrational Sum Frequency Generation Spectrometer from 3800 to 900 cm−1". Applied Spectroscopy 63, nr 5 (maj 2009): 528–37. http://dx.doi.org/10.1366/000370209788347057.
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We have built a broad bandwidth vibrational sum frequency generation (VSFG) spectrometer that can provide high-quality spectra over the range of 3800 to 900 cm−1. The spectrometer contains a commercial Ti:sapphire based 6 W regenerative amplifier as the master light source, a home-built pulse shaper to produce a narrow bandwidth 800 nm beam, a commercial optical parametric amplifier to generate a broad bandwidth femtosecond infrared (IR) pulse, and a detection system with a monochromator and a charge-coupled device (CCD). We applied this spectrometer to obtain VSFG spectra of a lipid monolayer at the air–water interface in the O–H stretching region (3800–3000 cm−1), the C–H stretching region (3100–2700 cm−1), the C–D stretching region (2300–2000 cm−1), the C=O stretching region (1800–1700 cm−1), and the PO2− symmetric stretching region (1200–1000 cm−1). We also obtained the VSFG spectrum of neat water in the O–H stretching region (3800–3000 cm−1) and the VSFG spectrum of a protein, α-synuclein, in the amide I region (1700–1600 cm−1) at the air–water interface. The spectrometer can provide a VSFG spectrum in the O–H stretching region (3800–3000 cm−1) without scanning the IR frequency. This feature will be useful in probing water dynamics at interfaces because the free OH and H-bonded OH can be investigated simultaneously. We have also provided instrumental details and discussed further improvements that should be beneficial to other researchers interested in setting up VSFG instrumentation.
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BOYES, STEPHEN G., MISTY D. ROWE, NATALIE J. SERKOVA, FERNANDO J. KIM, JAMES R. LAMBERT i PRIYA N. WERAHERA. "POLYMER-MODIFIED GADOLINIUM NANOPARTICLES FOR TARGETED MAGNETIC RESONANCE IMAGING AND THERAPY". Nano LIFE 01, nr 03n04 (wrzesień 2010): 263–75. http://dx.doi.org/10.1142/s1793984410000250.
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Functional imaging is a novel area in radiological sciences and allows for the non-invasive assessment and visualization of specific targets such as gene and protein expression, metabolic rates, and drug delivery in intact living subjects. As such, the field of molecular imaging has been defined as the non-invasive, quantitative, and repetitive imaging of biomolecules and biological processes in living organisms. For example, cancer cells may be genetically altered to attract molecules that alter the magnetic susceptibility, thereby permitting their identification by magnetic resonance imaging. These contrast agents and/or molecular reporters are seen as essential to the task of molecular medicine to increase both sensitivity and specificity of imaging. Therefore, there are five general principles which need to be fulfilled in order to conduct a successful in vivo molecular imaging study: (1) selection of appropriate cellular and subcellular targets; (2) development of suitable in vivo affinity ligands (molecular probes); (3) delivery of these probes to the target organ; (4) amplification strategies able to detect minimal target concentrations; and (5) development of imaging systems with high resolution. Although there has been a wide range of routes taken to incorporate both imaging agents and a disease-targeting moiety into diagnostic devices, arguably the most interesting of these routes employs the use of nanoparticles. Nanoscale diagnostic systems that incorporate molecular targeting agents and diagnostic imaging capabilities are emerging as the next-generation imaging agents and have the potential to dramatically improve the outcome of the imaging, diagnosis, and treatment of a wide range of diseases. The present review addresses chemical aspects in development of molecular probes based upon gadolinium nanoparticles and their potential role in translational clinical imaging and therapy.
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Zhang, Wenxian, Zhenzhen Chen, Yang Shi, Jiaqi Wang i Jingjing Zhang. "Integration of CRISPR/Cas with functional nucleic acids as versatile toolbox for non-nucleic acid target diagnostics: a review". Flexible and Printed Electronics 8, nr 2 (1.06.2023): 023002. http://dx.doi.org/10.1088/2058-8585/ace0cb.
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Abstract Non-nucleic acid targets, consisting primarily of metal ions, organic small molecules and proteins. They act as important biomolecules or cell surface markers, supplying integrated and comprehensive bio-diagnostic information for the early diagnosis and treatment of diseases. Meanwhile, the analysis of non-nucleic acid targets also offers the foundation for individualized medicine and precision therapy. Therefore, a versatile platform for non-nucleic acid targets requires development. Clustered regularly interspaced short palindromic repeats-associated protein (CRISPR/Cas) systems is driving a revolution in medical diagnostics due to high base-resolution and isothermal signal amplification. Nevertheless, the majority of CRISPR/Cas settings reported currently are targeted for nucleic acids, leaving restricted usage to non-nucleic acid targets. This is owing to the lack of suitable signal recognition transduction elements for connecting CRISPR to non-nucleic acid targets. Functional nucleic acids (FNAs), comprising aptamers and nucleic acid enzymes, are of great concern to the biological and medical professions because of their specific target recognition and catalytic properties. As appropriate, functional recognition elements, FNAs can be integrated into CRISPR/Cas systems to exploit the powerful capabilities of both. This review emphasizes the technical tricks of integrating CRISPR/Cas systems and FNAs for non-nucleic acid targeting diagnostic applications. We first offer a general overview and the current state of research in diagnostics for CRISPR/Cas and FNAs, respectively, highlighting strengths and shortcomings. A categorical summary of non-nucleic acid-targeted diagnostics is provided, with a key emphasis on fundamental insights into the versatile non-nucleic acid-targeted diagnostic toolbox. We then review emerging diagnostic strategies based on CRISPR/Cas systems and FNAs that are fast, accurate and efficient in detecting non-nucleic acid targets. Finally, we identify the challenges that remain in this emerging field and look to the future of the field, expanding to the integration of nanomaterials, development of wearable devices and point-of-care testing.
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Gurukandure, Asanka, Kacey G. Ortiz, Rashad R. Karimov i Christopher J. Easley. "Electrochemical Sensing of Cortisol in Human Saliva and Serum Using DNA-Steroid Conjugation with a Versatile DNA Nanostructure Sensor". ECS Meeting Abstracts MA2022-02, nr 61 (9.10.2022): 2270. http://dx.doi.org/10.1149/ma2022-02612270mtgabs.
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Having a generalizable point of care (POC) method for clinically relevant biomolecules would greatly enhance healthcare management and disease diagnosis. Recently our group developed a novel DNA nanostructure architecture for versatile detection of analytes which is generalizable for assaying several small molecules and their larger protein binding partners (e.g. antibodies) in human serum. The DNA nanostructure is built through on-electrode enzymatic ligation of three oligos for electrode attachment, anchor binding, and electrochemical signaling. In this study, we developed an economical synthetic approach for making oligonucleotide-steroid conjugates, and we explored the capability of these DNA nanostructure sensors for small molecule/steroid detection. Cortisol is a steroid hormone secreted by the hypothalamic-pituitary-adrenal system in response to the body’s stress level. As the main stress hormone, it controls processes such as immune, adrenal, circulatory, and metabolic. Moreover, anomalies of cortisol levels can result in serious conditions such as Addison’s disease, Cushing’s syndrome, and adrenal insufficiencies. Every year, 120,000 deaths are attributed, in part, to elevated levels of stress. To minimize these issues, a simplified method for cortisol sensing is vital. In this study, we conjugated cortisol to amine-tagged DNA and used the conjugates in our sensors. Anti-cortisol antibodies induced a 67% signal drop, validating conjugation. A calibration curve for cortisol showed a limit of detection of 800 pM and a dynamic range of 1 – 100 nM. The sensor was validated in saliva and human serum samples using the gold standard method, ELISA. Changing cortisol levels in two human patients' saliva samples were successfully detected after several collection times throughout a single day. As a potential point-of-care (POC) detection device, our novel cortisol biosensor could detect the hormone in human serum and saliva samples within 6 minutes.
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Correira, Joshua M., Paul R. Handali i Lauren J. Webb. "Characterizing Protein-Surface and Protein-Nanoparticle Conjugates: Activity, Binding, and Structure". Journal of Chemical Physics, 5.08.2022. http://dx.doi.org/10.1063/5.0101406.
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Many sensors and catalysts composed of proteins immobilized on inorganic materials have been reported over the past few decades. Despite some examples of functional protein-surface and protein-nanoparticle conjugates, thorough characterization of the biological-abiological interface at the heart of these materials and devices is often overlooked in lieu of demonstrating acceptable system performance. This has resulted in a focus on generating functioning protein-based devices without a concerted effort to develop reliable tools necessary to measure the fundamental properties of the bio-abio interface such as surface concentration, biomolecular structure, and activity. In this Perspective we discuss current methods used to characterize these critical properties of devices that operate by integrating a protein into both flat surfaces and nanoparticle materials. We highlight the advantages and drawbacks of each method as they relate to understanding the function of the protein-surface interface, and explore the manner in which an informed understanding of this complex interaction leads directly to the advancement of protein-based materials and technology.
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Naraprawatphong, Rinyarat, Genta Kawanaka, Masayoshi Hayashi, Akifumi Kawamura i Takashi Miyata. "Development of protein-recognition SPR devices by combination of SI-ATRP with biomolecular imprinting using protein ligands". Molecular Imprinting 4, nr 1 (16.01.2016). http://dx.doi.org/10.1515/molim-2016-0003.
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AbstractMolecularly imprinted polymer brush layers and gel layers with both a lectin (ConA) and an antibody-IgG as biomolecular ligands for a target protein were formed on surface plasmon resonance (SPR) sensor chips via surface-initiated atom transfer radical polymerization (SIATRP) without and with a crosslinker, respectively. While the IgG-imprinted brush layers chip had almost the same affinity constant for target IgG as the nonimprinted brush layer chip, the affinity constant of the IgG-imprinted gel layer chip was approximately twice than that of the nonimprinted gel layer chip. These indicate that chemical crosslinks are very important factor to create distinct molecular recognition sites by molecular imprinting. Thus, biomolecular imprinting that uses biomolecular ligands and crosslinkers enables us to design polymer layer chips with distinct molecular recognition sites with a strong affinity for a target biomolecule. The molecularly imprinted gel layers chips with lectin and antibody ligands are promising candidates for fabricating SPR sensor systems to monitor target biomolecules such as proteins.
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"Precision Nanomedicine Vol. 3, Issue 1 Table of Contents". Precision Nanomedicine 3, nr 1 (30.01.2020). http://dx.doi.org/10.33218/prnano3(1).toc.
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Hunziker P. et al.: Schistosomiasis: from established diagnostic assays to emerging micro/nanotechnology-based rapid field testing for clinical management and epidemiology Precis. Nanomed. 2020 January;3(1):439-458 POTENTIAL CLINICAL SIGNIFICANCE Abstract Schistosomiasis is a neglected invasive worm disease with a huge disease burden in developing countries, particularly in children, and is seen increasingly in non-endemic regions through transfer by travellers, expatriates, and refugees. Undetected and untreated infections may be responsible for the persistence of transmission. Rapid and accurate diagnosis is the key to treatment and control. So far, parasitological detection methods remain the cornerstone of Schistosoma infection diagnosis in endemic regions, but conventional tests have limited sensitivity, in particular in low-grade infection. Recent advances contribute to improved detection in clinical and field settings. The recent progress in micro- and nanotechnologies opens a road by enabling the design of new miniaturized point-of-care devices and analytical platforms, which can be used for the rapid detection of these infections. This review starts with an overview of currently available laboratory tests and their Atyabi F. et al.: The Effect of Fibronectin Coating on Protein Corona Structure and Cellular Uptake of Single-Walled Carbon Nanotubes, Precis. Nanomed. 2020 January;3(1):459-470 BASIC SCIENCE Abstract Protein coating, as an outstanding surface modification strategy, influence the organization of biomolecules in the interface of nanomaterials. In the present study, fibronectin (FN) was used to modify the surface chemistry of single-walled carbon nanotubes (SWNTs) and carboxylated SWNTs (CO2-SWNTs) to analyze its effects on the protein corona composition and cellular uptake. At first, the successful coating of FN on the surface of both SWNTs was confirmed by transmission electron microscopy (TEM) and Raman spectroscopy. The results showed that the biomolecular organization of SWNTs and CO2-SWNTs coronas was changed after FN coating based on the evidence obtained from the surface plasmon intensity of the samples. Moreover, the MTT assay and confocal microscopy imaging revealed less cytotoxicity and cellular uptake of SWNTs coronas in comparison to bulk samples, respectively. It is suggested that protein coating of SWNTs can modify the corona pattern and consequently the biological behavior of carbon nanotubes. Eichenberger RM, Toth I et al.: Development of natural and unnatural amino acid delivery systems against hookworm infection, Precis. Nanomed. 2020 January;3(1):471-482 POTENTIAL CLINICAL SIGNIFICANCE Abstract Peptide-based vaccines consist of short antigen fragments derived from a specific pathogen. Alone, these peptide fragments are poorly or non-immunogenic; however, when incorporated into a proper delivery system, they can trigger strong immune responses. To eliminate the need for toxic and often ineffective oral adjuvants, we designed single molecule-based self-adjuvating vaccines against hookworms using natural and unnatural hydrophobic amino acids. Two vaccine conjugates were synthesized, consisting of B-cell epitope p3, derived from the hookworm Na-APR-1 protein; universal T-helper peptide P25; and either double copies of unnatural lipoamino acid (2-amino-D,L-eicosanoic acid), or ten copies of the natural amino acid leucine. After challenge with the model hookworm, Nippostrongylus brasiliensis, mice orally immunized with the conjugates, but without adjuvant, generated antibody responses against the hookworm epitope, resulting in significantly reduced worm and egg burdens compared to control mice. We have demonstrated that vaccine nanoparticles composed exclusively of natural amino acids can be effective even when administered orally.
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Romero-Muñiz, C., J. G. Vilhena, R. Pérez, J. C. Cuevas i L. A. Zotti. "Recent Advances in Understanding the Electron Transport Through Metal-Azurin-Metal Junctions". Frontiers in Physics 10 (4.07.2022). http://dx.doi.org/10.3389/fphy.2022.950929.
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Azurin proteins are the workhorse of protein electronics. This is a branch of biomolecular electronics, a recent research field which investigates electronics based on biomolecules such as proteins, peptides, amino acids, bacterial nanowires or DNA. In general, the possibility of including biosystems in solid-state junctions has opened the way to the development of novel electrical devices, and proteins have attracted enormous attention thanks to their many interesting properties. In the particular case of metal-azurin-metal junctions, experimental measurements have revealed extremely efficient electron transport over large distances, showing conductance values which are higher than certain conjugated molecules of similar lengths. Moreover, the electrical current has often been found to be temperature-independent, which has been used as an evidence of coherent transport or quantum tunneling. Interesting effects have been observed, moreover, upon insertion of single amino-acid mutations. In spite of a huge amount of work, the exact mechanism for the charge flow through these systems is still under debate. In this review, we will revise the recent advances made in the electron-transport measurements of azurin-based junctions as well as the corresponding theoretical modelling. We will discuss the interpretation of the currently-available experimental results as well as the open issues which still remain to be clarified.
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Teker, Kasif. "A Scheme for Blocking Non-Specific Antibody Binding on Single Wall Carbon Nanotubes". MRS Proceedings 1092 (2008). http://dx.doi.org/10.1557/proc-1092-bb02-07.
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AbstractCarbon nanotubes have many unique properties such as high surface area, hollow cavities, and excellent mechanical and electrical properties. Interfacing carbon nanotubes with biological systems could lead to significant applications in various disease diagnoses. Significant progress in interfacing carbon nanotubes with biological materials has been made in key areas such as aqueous solubility, chemical and biological functionalization for biocompatibility and specificity, and electronic sensing of proteins. Bioconjugated nanotubes combined with the sensitive nanotube-based electronic devices would enable sensitive biosensors toward medical diagnostic. Furthermore, recent findings of improved cell membrane permeability for carbon nanotubes would also expand medical applications to therapeutics using carbon nanotubes as carriers in gene delivery systems. One of the main issues in nanobio systems is the specificity, which requires biofunctionalization of nanomaterials for recognition of only one type of target biomolecule. This study presents an effective functionalization scheme for preventing non-specific antibody binding on nanotubes. Non-specific antibody binding on nanotubes was successfully prevented by co-adsorption of a bio-compatible polymer PEG and a surfactant (NaDDBS) on nanotubes. Optical studies through confocal microscopy revealed very minimal non-specific antibody binding on the PEG/NaDDBS-coated nanotubes (WCC < 0.05) compared to high degree of non-specific antibody binding on nanotubes without PEG pretreatment (WCC > 0.80), as determined by weighted co-localization coefficients (WCC). In addition to the confocal microscopy studies, electronic detection studies revealed that PEG/NaDDBS pretreated devices exhibited very little conductance change due to antibody adsorption compared to the devices without any PEG/NaDDBS pretreatment. These findings indicate that the PEG/NaDDBS pretreatment is a very effective functionalization scheme in preventing non-specific antibody binding on nanotubes.
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Ho, Dean, Benjamin Chu, Hyeseung Lee, Karen Kuo i Carlo D. Montemagno. "Block Copolymer-Based Biomembranes Functionalized with Energy Transduction Proteins". MRS Proceedings 823 (2004). http://dx.doi.org/10.1557/proc-823-w11.8.
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AbstractBlock copolymer-based membranes can be functionalized with energy transducing proteins to reveal a versatile family of nanoscale materials. Our work has demonstrated the fabrication of protein-functionalized ABA triblock copolymer nanovesicles that possess a broad applicability towards areas like biosensing and energy production. ABA triblock copolymers possess certain advantages over lipid systems. For example, they can mimic biomembrane environments necessary for membrane protein refolding in a single chain (hydrophilic(A)- hydrophobic(B)-hydrophilic(A)), enabling large-area membrane fabrication using methods like Langmuir-Blodgett (LB) deposition. Furthermore, the robustness of the polymer molecules/structure result in spontaneous and rapid protein-functionalized nano-vesicle formation that retains structure as well as protein functionality for up to several months, compared to one to two weeks for the lipid systems (e.g. POPC). The membrane protein, Bacteriorhodopsin (BR), found in Halobacterium Halobium, is a light-actuated proton pump that develops gradients towards the demonstration of coupled functionality with other membrane proteins, such as the production of electricity through Bacteriorhodopsin activity-dependent reversal of Cytochrome C Oxidase (COX), found in Rhodobacter Sphaeroides. Protein-functionalized materials have the exciting potential of serving as the core technology behind a series of fieldable devices that are driven completely by biomolecules.
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Dey, Swarup, Adam Dorey, Leeza Abraham, Yongzheng Xing, Irene Zhang, Fei Zhang, Stefan Howorka i Hao Yan. "A reversibly gated protein-transporting membrane channel made of DNA". Nature Communications 13, nr 1 (28.04.2022). http://dx.doi.org/10.1038/s41467-022-28522-2.
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AbstractControlled transport of biomolecules across lipid bilayer membranes is of profound significance in biological processes. In cells, cargo exchange is mediated by dedicated channels that respond to triggers, undergo a nanomechanical change to reversibly open, and thus regulate cargo flux. Replicating these processes with simple yet programmable chemical means is of fundamental scientific interest. Artificial systems that go beyond nature’s remit in transport control and cargo are also of considerable interest for biotechnological applications but challenging to build. Here, we describe a synthetic channel that allows precisely timed, stimulus-controlled transport of folded and functional proteins across bilayer membranes. The channel is made via DNA nanotechnology design principles and features a 416 nm2 opening cross-section and a nanomechanical lid which can be controllably closed and re-opened via a lock-and-key mechanism. We envision that the functional DNA device may be used in highly sensitive biosensing, drug delivery of proteins, and the creation of artificial cell networks.
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Turhan, Berk, i Zeynep H. Gümüş. "A Brave New World: Virtual Reality and Augmented Reality in Systems Biology". Frontiers in Bioinformatics 2 (6.04.2022). http://dx.doi.org/10.3389/fbinf.2022.873478.
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How we interact with computer graphics has not changed significantly from viewing 2D text and images on a flatscreen since their invention. Yet, recent advances in computing technology, internetworked devices and gaming are driving the design and development of new ideas in other modes of human-computer interfaces (HCIs). Virtual Reality (VR) technology uses computers and HCIs to create the feeling of immersion in a three-dimensional (3D) environment that contains interactive objects with a sense of spatial presence, where objects have a spatial location relative to, and independent of the users. While this virtual environment does not necessarily match the real world, by creating the illusion of reality, it helps users leverage the full range of human sensory capabilities. Similarly, Augmented Reality (AR), superimposes virtual images to the real world. Because humans learn the physical world through a gradual sensory familiarization, these immersive visualizations enable gaining familiarity with biological systems not realizable in the physical world (e.g., allosteric regulatory networks within a protein or biomolecular pathways inside a cell). As VR/AR interfaces are anticipated to be explosive in consumer markets, systems biologists will be more immersed into their world. Here we introduce a brief history of VR/AR, their current roles in systems biology, and advantages and disadvantages in augmenting user abilities. We next argue that in systems biology, VR/AR technologies will be most useful in visually exploring and communicating data; performing virtual experiments; and education/teaching. Finally, we discuss our perspective on future directions for VR/AR in systems biology.
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Rocha, Igor, Gabrielle Cerqueira, Felipe Varella Penteado i Susana I. Córdoba de Torresi. "Electrical Stimulation and Conductive Polymers as a Powerful Toolbox for Tailoring Cell Behaviour in vitro". Frontiers in Medical Technology 3 (29.07.2021). http://dx.doi.org/10.3389/fmedt.2021.670274.
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Electrical stimulation (ES) is a well-known method for guiding the behaviour of nerve cells in in vitro systems based on the response of these cells to an electric field. From this perspective, understanding how the electrochemical stimulus can be tuned for the design of a desired cell response is of great importance. Most biomedical studies propose the application of an electrical potential to cell culture arrays while examining the cell response regarding viability, morphology, and gene expression. Conversely, various studies failed to evaluate how the fine physicochemical properties of the materials used for cell culture influence the observed behaviours. Among the various materials used for culturing cells under ES, conductive polymers (CPs) are widely used either in pristine form or in addition to other polymers. CPs themselves do not possess the optimal surface for cell compatibility because of their hydrophobic nature, which leads to poor protein adhesion and, hence, poor bioactivity. Therefore, understanding how to tailor the chemical properties on the material surface will determine the obtention of improved ES platforms. Moreover, the structure of the material, either in a thin film or in porous electrospun scaffolds, also affects the biochemical response and needs to be considered. In this review, we examine how materials based on CPs influence cell behaviour under ES, and we compile the various ES setups and physicochemical properties that affect cell behaviour. This review concerns the culture of various cell types, such as neurons, fibroblasts, osteoblasts, and Schwann cells, and it also covers studies on stem cells prone to ES. To understand the mechanistic behaviour of these devices, we also examine studies presenting a more detailed biomolecular level of interaction. This review aims to guide the design of future ES setups regarding the influence of material properties and electrochemical conditions on the behaviour of in vitro cell studies.