Journal articles: 'Biosenseur redox'

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Шохина, А. Г., В. В. Белоусов, and Д. С. Билан. "Генетически кодируемый биосенсор roKate для регистрации редокс-состояния пула глутатиона." Вестник Российского Государственного медицинского университета, no. 1 (March 14, 2019): 94–101. http://dx.doi.org/10.24075/vrgmu.2019.013.

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Генетически кодируемые биосенсоры на основе флуоресцентных белков представляют собой инструмент исследования ряда биологических процессов в живых системах в режиме реального времени. За последние годы было создано целое семейство биосенсоров, позволяющих визуализировать в живых клетках изменения редокс-состояния пула глутатиона. Целью настоящей работы была разработка нового биосенсора для регистрации соотношения 2GSH/GSSG на основе красного флуоресцентного белка mKate2. Для этого методом направленного мутагенеза в структуру флуоресцентного белка вносили пару аминокислотных остатков цистеина, которые при окислении окружающего пула глутатиона формируют дисульфидную связь, что приводит к изменению спектральных характеристик. Полученный биосенсор был протестирован in vitro на выделенном препарате белка, в частности, были исследованы спектральные характеристики, рН-чувствительность белка, окислительно-восстановительный потенциал. Кроме того, биосенсор, названный roKate, был протестирован в культуре живых клеток млекопитающих. Он отличается высокой яркостью и повышенной стабильностью сигнала при изменениях рН в физиологическом диапазоне. От других представителей данного семейства биосенсоров roKate отличается необратимым изменением сигнала при окислении в клетках млекопитающих. Применение данного сенсора предпочтительно в экспериментах с наличием длительного промежутка времени между воздействием на биологическую систему и последующим анализом вызванного эффекта, например в условиях длительной пробоподготовки.

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Albrecht, Simone C., Mirko C. Sobotta, Daniela Bausewein, Isabel Aller, Rüdiger Hell, Tobias P. Dick, and Andreas J. Meyer. "Redesign of Genetically Encoded Biosensors for Monitoring Mitochondrial Redox Status in a Broad Range of Model Eukaryotes." Journal of Biomolecular Screening 19, no. 3 (August 16, 2013): 379–86. http://dx.doi.org/10.1177/1087057113499634.

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The development of genetically encoded redox biosensors has paved the way toward chemically specific, quantitative, dynamic, and compartment-specific redox measurements in cells and organisms. In particular, redox-sensitive green fluorescent proteins (roGFPs) have attracted major interest as tools to monitor biological redox changes in real time and in vivo. Most recently, the engineering of a redox relay that combines glutaredoxin (Grx) with roGFP2 as a translational fusion (Grx1-roGFP2) led to a biosensor for the glutathione redox potential ( EGSH). The expression of this probe in mitochondria is of particular interest as mitochondria are the major source of oxidants, and their redox status is closely connected to cell fate decisions. While Grx1-roGFP2 can be expressed in mammalian mitochondria, it fails to enter mitochondria in various nonmammalian model organisms. Here we report that inversion of domain order from Grx1-roGFP2 to roGFP2-Grx1 yields a biosensor with perfect mitochondrial targeting while fully maintaining its biosensor capabilities. The redesigned probe thus allows extending in vivo observations of mitochondrial redox homeostasis to important nonmammalian model organisms, particularly plants and insects.

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Guo, Kai, Zirui Song, Gaoxing Wang, and Chengchun Tang. "Detecting Redox Potentials Using Porous Boron Nitride/ATP-DNA Aptamer/Methylene Blue Biosensor to Monitor Microbial Activities." Micromachines 13, no. 1 (January 4, 2022): 83. http://dx.doi.org/10.3390/mi13010083.

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Microbial activity has gained attention because of its impact on the environment and the quality of people’s lives. Most of today’s methods, which include genome sequencing and electrochemistry, are costly and difficult to manage. Our group proposed a method using the redox potential change to detect microbial activity, which is rooted in the concept that metabolic activity can change the redox potential of a microbial community. The redox potential change was captured by a biosensor consisting of porous boron nitride, ATP-DNA aptamer, and methylene blue as the fluorophore. This assembly can switch on or off when there is a redox potential change, and this change leads to a fluorescence change that can be examined using a multipurpose microplate reader. The results show that this biosensor can detect microbial community changes when its composition is changed or toxic metals are ingested.

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Li, Jiuming, Yuan Yu, Jun Qian, Yu Wang, Jinghua Zhang, and Jinfang Zhi. "A novel integrated biosensor based on co-immobilizing the mediator and microorganism for water biotoxicity assay." Analyst 139, no. 11 (2014): 2806–12. http://dx.doi.org/10.1039/c4an00243a.

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Zou, Quan, Gong Cheng, and Yu Zhang. "Study on electrochemical biosensor based on screen-printed electrode." Modern Physics Letters B 32, no. 34n36 (December 30, 2018): 1840061. http://dx.doi.org/10.1142/s0217984918400614.

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It is known that redox reaction can take place among the solutions of potassium ferrocyanide (K4[Fe(CN)6]), glucose (C6H[Formula: see text]O6) and glucose oxidase (Glucose Oxidase, GOD). In this work, the method of electrochemical biosensor detection based on screen printed electrode was used to observe the redox reaction among these solutions. The relationship between redox reaction and parameters was studied by examining the effects of concentration and scanning speed of three solutions.

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Perelmuter, Karen, Inés Tiscornia, Marcelo A. Comini, and Mariela Bollati-Fogolín. "Generation and Characterization of Stable Redox-Reporter Mammalian Cell Lines of Biotechnological Relevance." Sensors 22, no. 4 (February 9, 2022): 1324. http://dx.doi.org/10.3390/s22041324.

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Cellular functions such as DNA replication and protein translation are influenced by changes in the intracellular redox milieu. Exogenous (i.e., nutrients, deterioration of media components, xenobiotics) and endogenous factors (i.e., metabolism, growth) may alter the redox homeostasis of cells. Thus, monitoring redox changes in real time and in situ is deemed essential for optimizing the production of recombinant proteins. Recently, different redox-sensitive variants of green fluorescent proteins (e.g., rxYFP, roGFP2, and rxmRuby2) have been engineered and proved suitable to detect, in a non-invasive manner, perturbations in the pool of reduced and oxidized glutathione, the major low molecular mass thiol in mammals. In this study, we validate the use of cytosolic rxYFP on two cell lines widely used in biomanufacturing processes, namely, CHO-K1 cells expressing the human granulocyte macrophage colony-stimulating factor (hGM-CSF) and HEK-293. Flow cytometry was selected as the read-out technique for rxYFP signal given its high-throughput and statistical robustness. Growth kinetics and cellular metabolism (glucose consumption, lactate and ammonia production) of the redox reporter cells were comparable to those of the parental cell lines. The hGM-CSF production was not affected by the expression of the biosensor. The redox reporter cell lines showed a sensitive and reversible response to different redox stimuli (reducing and oxidant reagents). Under batch culture conditions, a significant and progressive oxidation of the biosensor occurred when CHO-K1-hGM-CSF cells entered the late-log phase. Medium replenishment restored, albeit partially, the intracellular redox homeostasis. Our study highlights the utility of genetically encoded redox biosensors to guide metabolic engineering or intervention strategies aimed at optimizing cell viability, growth, and productivity.

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Rafat, Neda, Paul Satoh, and Robert Mark Worden. "Electrochemical Biosensor for Markers of Neurological Esterase Inhibition." Biosensors 11, no. 11 (November 16, 2021): 459. http://dx.doi.org/10.3390/bios11110459.

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A novel, integrated experimental and modeling framework was applied to an inhibition-based bi-enzyme (IBE) electrochemical biosensor to detect acetylcholinesterase (AChE) inhibitors that may trigger neurological diseases. The biosensor was fabricated by co-immobilizing AChE and tyrosinase (Tyr) on the gold working electrode of a screen-printed electrode (SPE) array. The reaction chemistry included a redox-recycle amplification mechanism to improve the biosensor’s current output and sensitivity. A mechanistic mathematical model of the biosensor was used to simulate key diffusion and reaction steps, including diffusion of AChE’s reactant (phenylacetate) and inhibitor, the reaction kinetics of the two enzymes, and electrochemical reaction kinetics at the SPE’s working electrode. The model was validated by showing that it could reproduce a steady-state biosensor current as a function of the inhibitor (PMSF) concentration and unsteady-state dynamics of the biosensor current following the addition of a reactant (phenylacetate) and inhibitor phenylmethylsulfonylfluoride). The model’s utility for characterizing and optimizing biosensor performance was then demonstrated. It was used to calculate the sensitivity of the biosensor’s current output and the redox-recycle amplification factor as a function of experimental variables. It was used to calculate dimensionless Damkohler numbers and current-control coefficients that indicated the degree to which individual diffusion and reaction steps limited the biosensor’s output current. Finally, the model’s utility in designing IBE biosensors and operating conditions that achieve specific performance criteria was discussed.

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Cheng, Tzong-Jih, Hsien-Yi Hsiao, Pei-Chia Tsai, and Richie L. C. Chen. "Redoxless Electrochemical Capacitance Spectroscopy for Investigating Surfactant Adsorption on Screen-Printed Carbon Electrodes." Chemosensors 11, no. 6 (June 11, 2023): 343. http://dx.doi.org/10.3390/chemosensors11060343.

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Electrochemical impedance spectroscopy (EIS) is a sensitive analytical method for surface and bulk properties. Classical EIS and derived electrochemical capacitance spectroscopy (ECS) with a redox couple are label-free approaches for biosensor development, but doubts arise regarding interpretability when a redox couple is employed (redox EIS) due to interactions between electroactive probes and interfacial charges or forced potential. Here, we demonstrated redoxless ECS for directly determining surfactant adsorption on screen-printed carbon electrodes (SPCEs), validated through a simulation of equivalent circuits and the electrochemistry of electronic dummy cells. Redoxless ECS provides excellent capacitance plot loci for quantifying the interfacial permittivity of di-electric layers on electrode surfaces. Redoxless ECS was compared with redox EIS/ECS, revealing a favorable discrimination of interfacial capacitances under both low and high SDS coverage on SPCEs and demonstrating potential for probeless (reagentless) sensing. Furthermore, the proposed method was applied in an electrolyte without a redox couple and bare electrodes, obtaining a high performance for the adsorption of surfactants Tween-20, Triton-X100, sodium dodecyl sulfate, and tetrapropylammonium bromide. This approach offers a simple and straightforward means for a semi-quantitative evaluation of small molecule interactions with electrode surfaces. Our proposed approach may serve as a starting point for future probeless (reagentless) and label-free biosensors based on electrochemistry, eliminating disturbance with surface charge properties and minimizing forced potential bias by avoiding redox couples. An unambiguous and quantitative determination of physicochemical properties of biochemically recognizable layers will be relevant for biosensor development.

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Zhou, Yaoyu, Lin Tang, Xia Xie, Guangming Zeng, Jiajia Wang, Yaocheng Deng, Guide Yang, Chen Zhang, Yi Zhang, and Jun Chen. "Sensitive impedimetric biosensor based on duplex-like DNA scaffolds and ordered mesoporous carbon nitride for silver(i) ion detection." Analyst 139, no. 24 (2014): 6529–35. http://dx.doi.org/10.1039/c4an01607f.

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Bunea, Mihaela-Cristina, Teodor Adrian Enache, and Victor Constantin Diculescu. "In situ Electrochemical Evaluation of the Interaction of dsDNA with the Proteasome Inhibitor Anticancer Drug Bortezomib." Molecules 28, no. 7 (April 6, 2023): 3277. http://dx.doi.org/10.3390/molecules28073277.

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Bortezomib is an inhibitor of proteasomes and an anti-cancer drug. Although bortezomib is considered a safe drug, as confirmed by cytotoxicity assays, recent reports highlighted the possibility of interaction between bortezomib and cellular components, with detrimental long-term effects. The evaluation of the interaction between bortezomib and dsDNA was investigated in bulk solution and using a dsDNA electrochemical biosensor. The binding of bortezomib to dsDNA involved its electroactive centers and led to small morphological modifications in the dsDNA double helix, which were electrochemically identified through changes in the guanine and adenine residue oxidation peaks and confirmed by electrophoretic and spectrophotometric measurements. The redox product of bortezomib amino group oxidation was electrochemically generated in situ on the surface of the dsDNA electrochemical biosensor. The redox product of bortezomib was shown to interact primarily with guanine residues, preventing their oxidation and leading to the formation of bortezomib–guanine adducts, which was confirmed by control experiments with polyhomonucleotides electrochemical biosensors and mass spectrometry. An interaction mechanism between dsDNA and bortezomib is proposed, and the formation of the bortezomib redox product–guanine adduct explained.

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Quynh Anh, Le Huu. "SYNTHESIS OF BIOTINYLATED FERROCENE, AND ITS APPLICATION AS A REDOX PROBE FOR ELECTROCHEMICAL IMMUNOSENSOR." Vietnam Journal of Science and Technology 54, no. 2C (March 19, 2018): 441. http://dx.doi.org/10.15625/2525-2518/54/2c/11873.

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The coupling compound of Biotin (Vitamin H) and redox molecule ferrocene throughcovalent bonding was studied. Synthesis and structure identification of Biotinylated 1 - (- 2-aminoethyl) ferrocene were performed by 1H-NMR, 13C-NMR and MS. The ultimate goal of thispaper is to develop derivatives of ferroceneservingas an electrochemical probe that wouldenhance the performance of immunosensor.An immunosensor based on polypyrrole-streptavidinlayer as platform for immobilization of biotinylatedferrocene and antibodies was developed. Themeasurement of redox signal of ferrocene was analyzed by differential pulse voltammetry(DPV) method and underlined a variation of redox properties upon the antigen interaction. Theintroduction of the redox biotinylatedferrocene into streptavidin-polypyrrole layer affords a goodsensitivity of the biosensor with a detection limit of 0.16 pg.mL-1.

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Fusco, Giovanni, Paolo Bollella, Franco Mazzei, Gabriele Favero, Riccarda Antiochia, and Cristina Tortolini. "Catalase-Based Modified Graphite Electrode for Hydrogen Peroxide Detection in Different Beverages." Journal of Analytical Methods in Chemistry 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/8174913.

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A catalase-based (NAF/MWCNTs) nanocomposite film modified glassy carbon electrode for hydrogen peroxide (H2O2) detection was developed. The developed biosensor was characterized in terms of its bioelectrochemical properties. Cyclic voltammetry (CV) technique was employed to study the redox features of the enzyme in the absence and in the presence of nanomaterials dispersed in Nafion® polymeric solution. The electron transfer coefficient, α, and the electron transfer rate constant, ks, were found to be 0.42 and 1.71 s−1, at pH 7.0, respectively. Subsequently, the same modification steps were applied to mesoporous graphite screen-printed electrodes. Also, these electrodes were characterized in terms of their main electrochemical and kinetic parameters. The biosensor performances improved considerably after modification with nanomaterials. Moreover, the association of Nafion with carbon nanotubes retained the biological activity of the redox protein. The enzyme electrode response was linear in the range 2.5–1150 μmol L−1, with LOD of 0.83 μmol L−1. From the experimental data, we can assess the possibility of using the modified biosensor as a useful tool for H2O2 determination in packaged beverages.

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Medvedeva, Anastasia S., Elena I. Dyakova, Lyubov S. Kuznetsova, Vladislav G. Mironov, George K. Gurkin, Tatiana V. Rogova, Anna S. Kharkova, et al. "A Two-Mediator System Based on a Nanocomposite of Redox-Active Polymer Poly(thionine) and SWCNT as an Effective Electron Carrier for Eukaryotic Microorganisms in Biosensor Analyzers." Polymers 15, no. 16 (August 8, 2023): 3335. http://dx.doi.org/10.3390/polym15163335.

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Electropolymerized thionine was used as a redox-active polymer to create a two-mediated microbial biosensor for determining biochemical oxygen demand (BOD). The electrochemical characteristics of the conducting system were studied by cyclic voltammetry and electrochemical impedance spectroscopy. It has been shown that the most promising in terms of the rate of interaction with the yeast B. adeninivorans is the system based on poly(thionine), single-walled carbon nanotubes (SWCNT), and neutral red (kint = 0.071 dm3/(g·s)). The biosensor based on this system is characterized by high sensitivity (the lower limit of determined BOD concentrations is 0.4 mgO2/dm3). Sample analysis by means of the developed analytical system showed that the results of the standard dilution method and those using the biosensor differed insignificantly. Thus, for the first time, the fundamental possibility of effectively using nanocomposite materials based on SWCNT and the redox-active polymer poly(thionine) as one of the components of two-mediator systems for electron transfer from yeast microorganisms to the electrode has been shown. It opens up prospects for creating stable and highly sensitive electrochemical systems based on eukaryotes.

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Zhang, Yun, Fang Liu, Jinfang Nie, Fuyang Jiang, Caibin Zhou, Jiani Yang, Jinlong Fan, and Jianping Li. "An electrochemical sensing platform based on local repression of electrolyte diffusion for single-step, reagentless, sensitive detection of a sequence-specific DNA-binding protein." Analyst 139, no. 9 (2014): 2193–98. http://dx.doi.org/10.1039/c4an00096j.

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This paper describes for the first time an electrochemical biosensor, which employs a DNA probe modified with a redox tag close to electrode surface, for picomolar detection of a sequence-specific DNA-binding protein.

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Le, Hien T. Ngoc, Jinsoo Park, and Sungbo Cho. "A Probeless Capacitive Biosensor for Direct Detection of Amyloid Beta 1-42 in Human Serum Based on an Interdigitated Chain-Shaped Electrode." Micromachines 11, no. 9 (August 21, 2020): 791. http://dx.doi.org/10.3390/mi11090791.

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Amyloid beta (aβ) 1-42, a peptide that is 1-42 amino acids long, is a major component of senile plaques in the brains of patients with Alzheimer’s disease. Aβ detection has become an essential antecedence to predict the declining mental abilities of patients. In this paper, a probeless capacitive biosensor for the non-Faradaic detection of aβ 1-42 peptide was developed by immobilizing a specific anti-aβ antibody onto a self-assembled monolayer functionalized interdigitated chain-shaped electrode (anti-aβ/SAM/ICE). The novelty and difference of this article from previous studies is the direct detection of aβ peptide with no redox probe ((Fe(CN)6)3−/4−), which can avoid the denaturation of the protein caused by the metallization (binding of aβ to metal ion Fe which is presented in the redox couple). The direct detection of aβ with no redox probe is performed by non-Faradaic capacitive measurement, which is greatly different from the Faradaic measurement of the charge transfer resistance of the redox probe. The detection of various aβ 1-42 peptide concentrations in human serum (HS) was performed by measuring the relative change in electrode interfacial capacitance due to the specific antibody-aβ binding. Capacitance change in the anti-aβ/SAM/ICE biosensor showed a linear detection range between 10 pg mL−1 and 104 pg mL−1, and a detection limit of 7.5 pg mL−1 in HS, which was much lower than the limit of detection for CSF aβ 1-42 (~500 pg mL−1) and other biosensors. The small dissociation constant Kd of the antibody-antigen interaction was also found to be 0.016 nM in HS, indicating the high binding affinity of the anti-aβ/SAM/ICE biosensor in the recognizing of aβ 1-42. Thus, the developed sensor can be used for label-free and direct measurement of aβ 1-42 peptide and for point-of-care diagnosis of Alzheimer’s disease without redox probe.

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Shokhina, Arina G., Alexander I. Kostyuk, Yulia G. Ermakova, Anastasiya S. Panova, Dmitry B. Staroverov, Evgeny S. Egorov, Mikhail S. Baranov, et al. "Red fluorescent redox-sensitive biosensor Grx1-roCherry." Redox Biology 21 (February 2019): 101071. http://dx.doi.org/10.1016/j.redox.2018.101071.

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Piras, L., M. Adami, S. Fenu, M. Dovis, and C. Nicolini. "Immunoenzymatic application of a redox potential biosensor." Analytica Chimica Acta 335, no. 1-2 (December 1996): 127–35. http://dx.doi.org/10.1016/s0003-2670(96)00321-2.

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Yuhana Ariffin, Eda, Lee Yook Heng, Ling Ling Tan, Nurul Huda Abd Karim, and Siti Aishah Hasbullah. "A Highly Sensitive Impedimetric DNA Biosensor Based on Hollow Silica Microspheres for Label-Free Determination of E. coli." Sensors 20, no. 5 (February 26, 2020): 1279. http://dx.doi.org/10.3390/s20051279.

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A novel label-free electrochemical DNA biosensor was constructed for the determination of Escherichia coli bacteria in environmental water samples. The aminated DNA probe was immobilized onto hollow silica microspheres (HSMs) functionalized with 3-aminopropyltriethoxysilane and deposited onto a screen-printed electrode (SPE) carbon paste with supported gold nanoparticles (AuNPs). The biosensor was optimized for higher specificity and sensitivity. The label-free E. coli DNA biosensor exhibited a dynamic linear response range of 1 × 10−10 µM to 1 × 10−5 µM (R2 = 0.982), with a limit of detection at 1.95 × 10−15 µM, without a redox mediator. The sensitivity of the developed DNA biosensor was comparable to the non-complementary and single-base mismatched DNA. The DNA biosensor demonstrated a stable response up to 21 days of storage at 4 ℃ and pH 7. The DNA biosensor response was regenerable over three successive regeneration and rehybridization cycles.

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Mauzeroll, Janine. "A High-Throughput Strategy for Glycine Oxidase Biosensor Development Reveals Glycine Release from Cultured Cells." ECS Meeting Abstracts MA2022-01, no. 43 (July 7, 2022): 1861. http://dx.doi.org/10.1149/ma2022-01431861mtgabs.

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Glycine is an important biomarker in clinical analysis due to its involvement in multiple physiological processes. As such, the need for low-cost analytical tools for glycine detection is growing. As a neurotransmitter, glycine is involved in inhibitory and excitatory neurochemical transmission in the central nervous system. In this work, we present a 10 μM Pt-based electrochemical enzymatic biosensor for localized real time measurements of glycine. This biosensor relies on amperometric readout and does not require additional redox mediators. The biosensor was characterized and applied for real-time glycine detection from cells, mainly HEK 293 cells and primary rat astrocytes. Taken together, this study demonstrates a glycine oxidase based biosensor useful for extracting pertinent information about glycine levels in a wide range of biological contexts.

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Shokhina, AG, VV Belousov, and DS Bilan. "A genetically encoded biosensor roKate for monitoring the redox state of the glutathione pool." Laboratory diagnostics, no. 1 (March 14, 2019): 86–92. http://dx.doi.org/10.24075/brsmu.2019.013.

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Genetically encoded fluorescent sensors are exploited to study a variety of biological processes in living organisms in real time. In recent years, a whole family of biosensors has been developed, serving to visualize changes in the glutathione redox state. The aim of our experiment was to design a biosensor based on the red fluorescent protein mKate2 for measuring the 2GSH/GSSG ratio. A pair of cysteine amino acid residues were introduced into the structure of the fluorescent protein using site-directed mutagenesis. These residues form a disulfide bridge when the surrounding glutathione pool is oxidized, affecting the spectral characteristics of the protein. Our biosensor, which we called roKate, was tested in vitro on an isolated protein. Specifically, we examined the spectral characteristics, pH and the redox potential of the sensor. Additionally, the performance of roKate was evaluated using the culture of living mammalian cells. The fluorescent signal emitted by the sensor was very bright and remarkably stable under pH conditions varying in the physiological range. Irreversibly oxidized in mammalian cells, roKate stands out from other members of this biosensor family. This biosensor should be preferred in the experiments when the time between the manipulations with the biological object and the subsequent analysis of the induced effect is substantial, as is the case with long sample preparation.

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Perchikov, Roman N., Daria V. Provotorova, Anna S. Kharkova, Vyacheslav A. Arlyapov, Anastasia S. Medvedeva, Andrey V. Machulin, Andrey E. Filonov, and Anatoly N. Reshetilov. "Bioanalytical System for Determining the Phenol Index Based on Pseudomonas putida BS394(pBS216) Bacteria Immobilized in a Redox-Active Biocompatible Composite Polymer “Bovine Serum Albumin–Ferrocene–Carbon Nanotubes”." Polymers 14, no. 24 (December 8, 2022): 5366. http://dx.doi.org/10.3390/polym14245366.

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The possibility of using the microorganisms Pseudomonas sp. 7p-81, Pseudomonas putida BS394(pBS216), Rhodococcus erythropolis s67, Rhodococcus pyridinivorans 5Ap, Rhodococcus erythropolis X5, Rhodococcus pyridinivorans F5 and Pseudomonas veronii DSM 11331T as the basis of a biosensor for the phenol index to assess water environments was studied. The adaptation of microorganisms to phenol during growth was carried out to increase the selectivity of the analytical system. The most promising microorganisms for biosensor formation were the bacteria P. putida BS394(pBS216). Cells were immobilized in redox-active polymers based on bovine serum albumin modified by ferrocenecarboxaldehyde and based on a composite with a carbon nanotube to increase sensitivity. The rate constants of the interaction of the redox-active polymer and the composite based on it with the biomaterial were 193.8 and 502.8 dm3/(g·s) respectively. For the biosensor created using hydrogel bovine serum albumin-ferrocene-carbon nanotubes, the lower limit of the determined phenol concentrations was 1 × 10−3 mg/dm3, the sensitivity coefficient was (5.8 ± 0.2)∙10−3 μA·dm3/mg, Michaelis constant KM = 230 mg/dm3, the maximum rate of the enzymatic reaction Rmax = 217 µA and the long-term stability of the bioanalyzer was 11 days. As a result of approbation, it was found that the urban water phenol content differed insignificantly, measured by creating a biosensor and using the standard photometric method.

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Hidalgo, Miltha, Vania Rodríguez, Christine Kreindl, and Omar Porras. "Biological Redox Impact of Tocopherol Isomers Is Mediated by Fast Cytosolic Calcium Increases in Living Caco-2 Cells." Antioxidants 9, no. 2 (February 14, 2020): 155. http://dx.doi.org/10.3390/antiox9020155.

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Most of the biological impacts of Vitamin E, including the redox effects, have been raised from studies with α-tocopherol only, despite the fact that tocopherol-containing foods carry mixed tocopherol isomers. Here, we investigated the cellular mechanisms involved in the immediate antioxidant responses evoked by α-, γ- and δ-tocopherol in Caco-2 cells. In order to track the cytosolic redox impact, we performed imaging on cells expressing HyPer, a fluorescent redox biosensor, while cytosolic calcium fluctuations were monitored by means of Fura-2 dye and imaging. With this approach, we could observe fast cellular responses evoked by the addition of α-, γ- and δ-tocopherol at concentrations as low as 2.5 μM. Each isomer induced rapid and consistent increases in cytosolic calcium with fast kinetics, which were affected by chelation of extracellular Ca2+, suggesting that tocopherols promoted a calcium entry upon the contact with the plasma membrane. In terms of redox effects, δ-tocopherol was the only isomer that evoked a significant change in the HyPer signal at 5 μM. By mimicking Ca2+ entry with ionomycin and monensin, a decline in the HyPer signal was induced as well. Finally, by silencing calcium with 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA), an intracellular Ca2+ chelator, none of the isomers were able to induce redox changes. Altogether, our data indicate that an elevation in cytoplasmic Ca2+ is necessary for the development of a tocopherol-induced antioxidant impact on the cytoplasm of Caco-2 cells reported by HyPer biosensor.

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Ben Jrad, Amani, Hussein Kanso, Delphine Raviglione, Thierry Noguer, Nicolas Inguimbert, and Carole Calas-Blanchard. "Salen/salan metallic complexes as redox labels for electrochemical aptasensors." Chemical Communications 55, no. 85 (2019): 12821–24. http://dx.doi.org/10.1039/c9cc07575e.

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Jayawardena, Asanka, Sher Maine Tan, Mark B. Richardson, Jianxiong Chan, Helmut Thissen, Nicolas H. Voelcker, and Patrick Kwan. "Industry Viable Electrochemical DNA Detection Sensor Architecture via a Stem-Loop Methylene Blue Redox Reporter and Rapid In Situ Probe Immobilization Method for Pharmacogenetic Biomarker Testing Application." Journal of The Electrochemical Society 169, no. 1 (January 1, 2022): 017508. http://dx.doi.org/10.1149/1945-7111/ac4a4d.

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Identification of biomarkers in clinical applications for diagnostics at the point-of-care (POC) setting requires the development of industry viable biosensing platform. Herein, we report such development of biosensor architecture for the detection of pharmacogenetic biomarker HLA-B*15:02 gene. The biosensor architecture comprises of an oligonucleotide stem-loop probe modified with a methylene blue redox (MB) reporter, immobilized via a rapid “printing” method on the commercially available disposable screen-printed electrodes (SPE). The square wave voltammetric measurements on the DNA sensor showed a clear peak difference of ∼80 nA with a significant difference in peak height values of the faradaic current generated for the MB redox moiety between the positive control (biotin-modified 19 based oligonucleotides with the sequence mimicking the specific region of the HLA-B*15:02 allele and complementary to the probe sequence) and negative control samples (biotin-modified 19 based oligonucleotides with the sequence unrelated to the probe sequence and the HLA-B*15:02 allele). These initial proof of concept results provide support for the possibility of using this signal-off biosensor architecture in the intended pharmacogenetic biomarker testing.

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Wong, Elicia L. S., and J. Justin Gooding. "Electrochemical Transduction of DNA Hybridization by Long-Range Electron Transfer." Australian Journal of Chemistry 58, no. 4 (2005): 280. http://dx.doi.org/10.1071/ch04265.

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For the detection of DNA hybridization, there are two main challenges that current research aims to overcome: lower detection limits and higher selectivity. We describe here the development of an electrochemical biosensor that used redox-active intercalators to transduce DNA hybridization by long-range electron transfer through DNA duplexes. This study outlines how the sensitivity and selectivity of the biosensor was tuned by careful control of the surface chemistry of the DNA-modified interface. The DNA-modified interface is composed of thiolated DNA and a diluent component, both of which are self-assembled onto a gold electrode. The resultant DNA biosensor has excellent selectivity towards single-base mismatch detection, whilst both the detection limit and sensitivity can easily be adjusted by varying the length of the diluent molecule relative to the length of the thiol linker at the 3´ end of the DNA. The one limitation of such a detection scheme is the slow assay time, which is a consequence of the slow kinetics of intercalation of the redox molecule into the duplexes. Approaches to reducing the assay time to a more commercially viable timescale are outlined.

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Sun, Xiao Bin, and Zhan Fang Ma. "An Amperometric Glucose Biosensor Based on Pd-Pt Nanodendrites and Chitosan Matrix." Advanced Materials Research 643 (January 2013): 162–65. http://dx.doi.org/10.4028/www.scientific.net/amr.643.162.

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We report on the utilization of Pd-Pt nanodendrites (Pd-Pt NDs) to create a highly responsive glucose biosensor. Glucose oxidase was simply mixed with Pd-Pt NDs and cross-linked on the Pt electrode with chitosan (CHIT) medium by glutaraldehyde. The biosensor showed low linear detection limit (0.6 μM), wide linear detection range (0.001-5 mM). The excellent performance of the biosensor is attributed to relatively large surface areas and particularly catalytic active of Pd-Pt NDs, and good biocompatibility of CHIT, which enhances the enzyme absorption and promotes electron transfer between redox enzymes and the surface of electrodes. This composite film can be easily extended to immobilize other biomolecules.

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Tsujimoto, Masaki, Kenichi Maruyama, Yuji Mishima, and Junko Motonaka. "Enzyme Biosensor Based on an Electropolymerized Osmium Redox Polymer." International Journal of Modern Physics B 17, no. 08n09 (April 10, 2003): 1517–22. http://dx.doi.org/10.1142/s0217979203019253.

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Electrochemical polymerizations of metal complex as electron mediator in aqueous solution have been developed. The metal complexes as electron mediator of biosensor for practical application have a rapid electron transfer rate, a chemical stability, and an accessible manipulation. The electro-polymerized redox polymer relatively decreased the enzyme and catalytic activity, although these could be treated in organic solvent. In this work, the water-soluble osmium complex-modified pyrrole derivatives with long, flexible spacer chain were synthesized. The electro-polymerized redox polymer was generally produced by potential sweep copolymerization (-400 mV -/+1200 mV (vs. Ag|AgCl(sat.KCl))) of water-soluble osmium complex-modified pyrrole monomer and glucose oxidase (GOD) on the top of a Pt electrode in aqueous solution. With the electro-polymerized osmium redox polymer modified electrode, calibration graphs for measurements of glucose and the effect of concomitant compounds, dissolved oxygen and the lifetimes of the sensor were electrochemistry examined, respectively. Under optimal conditions, the response of the sensors was in the concentration ranges of 0.6 mM-100 mM for glucose.

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Ulianas, Alizar, Lee Yook Heng, Han-Yih Lau, Zamri Ishak, and Tan Ling Ling. "Single-step and reagentless analysis of genetically modified soybean DNA with an electrochemical DNA biosensor." Anal. Methods 6, no. 16 (2014): 6369–74. http://dx.doi.org/10.1039/c4ay00881b.

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A simple procedure for voltammetric determination of genetically modified DNA without introduction of a redox indicator into DNA hybridization medium is described. The DNA biosensor is designed where both DNA hybridization and indicator intercalation detections can be performed in a single-step.

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Amin, Mohsin, Badr M. Abdullah, Stephen R. Wylie, Samuel J. Rowley-Neale, Craig E. Banks, and Kathryn A. Whitehead. "The Voltammetric Detection of Cadaverine Using a Diamine Oxidase and Multi-Walled Carbon Nanotube Functionalised Electrochemical Biosensor." Nanomaterials 13, no. 1 (December 22, 2022): 36. http://dx.doi.org/10.3390/nano13010036.

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Cadaverine is a biomolecule of major healthcare importance in periodontal disease; however, current detection methods remain inefficient. The development of an enzyme biosensor for the detection of cadaverine may provide a cheap, rapid, point-of-care alternative to traditional measurement techniques. This work developed a screen-printed biosensor (SPE) with a diamine oxidase (DAO) and multi-walled carbon nanotube (MWCNT) functionalised electrode which enabled the detection of cadaverine via cyclic voltammetry and differential pulse voltammetry. The MWCNTs were functionalised with DAO using carbodiimide crosslinking with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and N-Hydroxysuccinimide (NHS), followed by direct covalent conjugation of the enzyme to amide bonds. Cyclic voltammetry results demonstrated a pair of distinct redox peaks for cadaverine with the C-MWCNT/DAO/EDC-NHS/GA SPE and no redox peaks using unmodified SPEs. Differential pulse voltammetry (DPV) was used to isolate the cadaverine oxidation peak and a linear concentration dependence was identified in the range of 3–150 µg/mL. The limit of detection of cadaverine using the C-MWCNT/DAO/EDC-NHS/GA SPE was 0.8 μg/mL, and the biosensor was also found to be effective when tested in artificial saliva which was used as a proof-of-concept model to increase the Technology Readiness Level (TRL) of this device. Thus, the development of a MWCNT based enzymatic biosensor for the voltammetric detection of cadaverine which was also active in the presence of artificial saliva was presented in this study.

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Lowery, William, Pragun R. Tuladhar, and David E. Cliffel. "Optimization of Osmium Metal Loading in Redox Polymer for Biosensing Applications." ECS Meeting Abstracts MA2023-02, no. 64 (December 22, 2023): 3281. http://dx.doi.org/10.1149/ma2023-02643281mtgabs.

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Historically, polymers have been utilized to provide a three-dimensional interface for proteins and enzymes in devices such as biosensors and biohybrid solar cells. While these polymers can provide a scaffold onto which biomolecules can be immobilized, their true utility comes from the ability of some polymers to enhance electrochemical processes. Osmium-containing redox polymers are crucial in biosensor applications because they can exclude signals from interferent molecules by shifting the operating voltage of the working electrode. While osmium redox polymers have been used for many years, there is little literature available discussing the incorporation of the osmium onto the polymer backbone. Specifically, how the polymer properties are affected by varying metal loadings is particularly lacking. In this work, the metal loading, or the percentage of polymer side chains containing an osmium unit, is varied from 2 – 32% (as determined by 1H NMR). The electrochemical properties of the osmium-containing polymers are then determined by cyclic voltammetry. It is hypothesized that higher osmium loading will correlate with easier electron transfer and overall improved sensor performance when interfaced with biosensors. Preliminary data has supported this hypothesis and further reinforces the need for such a comprehensive, yet fundamental study of osmium redox polymers to inform the biosensor community.

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Liu, Chun Xiu, Hong Min Liu, Qing De Yang, Nan Sen Lin, Yi Lin Song, Li Wang, and Xin Xia Cai. "Highly Sensitive Determination of Dopamine Using Osmium/Nafion Modified Disposable Integrated Biosensor." Advanced Materials Research 60-61 (January 2009): 311–14. http://dx.doi.org/10.4028/www.scientific.net/amr.60-61.311.

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A biosensor based on gold electrode modified by Pt nanaoparticles/Osmium redox polymer/Nafion trilayer film was fabricated and used for selective and sensitive determination of dopamine. The biosensor is explored for DA sensing using the cyclic voltammetry (CV), amperometric and differential pulse voltammetric (DPV) methods. The CV anodic peak currents showed a linear range with a correlation coefficient of 0.996, localized in the concentration range 0~192 μM. The differential pulse voltammetric (DPV) peak currents were linear with DA concentration during 2~425 μM with correlation coefficient of 0.99. The biosensor showed high sensitivity of 0.5 nA /nM cm2 and excellent reproducibility with the detection limit of ~10 nM (S/N=3) for the determination of DA. The easy fabrication, low detection limit and high sensitivity of the integrated biosensor making it particularly suitable for the analytical purposes.

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El Aamri, Maliana, Ghita Yammouri, Hasna Mohammadi, Aziz Amine, and Hafsa Korri-Youssoufi. "Electrochemical Biosensors for Detection of MicroRNA as a Cancer Biomarker: Pros and Cons." Biosensors 10, no. 11 (November 20, 2020): 186. http://dx.doi.org/10.3390/bios10110186.

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Cancer is the second most fatal disease in the world and an early diagnosis is important for a successful treatment. Thus, it is necessary to develop fast, sensitive, simple, and inexpensive analytical tools for cancer biomarker detection. MicroRNA (miRNA) is an RNA cancer biomarker where the expression level in body fluid is strongly correlated to cancer. Various biosensors involving the detection of miRNA for cancer diagnosis were developed. The present review offers a comprehensive overview of the recent developments in electrochemical biosensor for miRNA cancer marker detection from 2015 to 2020. The review focuses on the approaches to direct miRNA detection based on the electrochemical signal. It includes a RedOx-labeled probe with different designs, RedOx DNA-intercalating agents, various kinds of RedOx catalysts used to produce a signal response, and finally a free RedOx indicator. Furthermore, the advantages and drawbacks of these approaches are highlighted.

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Liu, Yang, Robert Landick, and Srivatsan Raman. "A Regulatory NADH/NAD+ Redox Biosensor for Bacteria." ACS Synthetic Biology 8, no. 2 (January 11, 2019): 264–73. http://dx.doi.org/10.1021/acssynbio.8b00485.

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Zhang, Jie, Nikolaus Sonnenschein, Thomas P. B. Pihl, Kasper R. Pedersen, Michael K. Jensen, and Jay D. Keasling. "Engineering an NADPH/NADP+Redox Biosensor in Yeast." ACS Synthetic Biology 5, no. 12 (July 25, 2016): 1546–56. http://dx.doi.org/10.1021/acssynbio.6b00135.

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Hamami, M., M. Bouaziz, N. Raouafi, A. Bendounan, and H. Korri-Youssoufi. "MoS2/PPy Nanocomposite as a Transducer for Electrochemical Aptasensor of Ampicillin in River Water." Biosensors 11, no. 9 (September 1, 2021): 311. http://dx.doi.org/10.3390/bios11090311.

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We report the design of an electrochemical aptasensor for ampicillin detection, which is an antibiotic widely used in agriculture and considered to be a water contaminant. We studied the transducing potential of nanostructure composed of MoS2 nanosheets and conductive polypyrrole nanoparticles (PPyNPs) cast on a screen-printed electrode. Fine chemistry is developed to build the biosensors entirely based on robust covalent immobilizations of naphthoquinone as a redox marker and the aptamer. The structural and morphological properties of the nanocomposite were studied by SEM, AFM, and FT-IR. High-resolution XPS measurements demonstrated the formation of a binding between the two nanomaterials and energy transfer affording the formation of heterostructure. Cyclic voltammetry and electrochemical impedance spectroscopy were used to analyze their electrocatalytic properties. We demonstrated that the nanocomposite formed with PPyNPs and MoS2 nanosheets has electro-catalytic properties and conductivity leading to a synergetic effect on the electrochemical redox process of the redox marker. Thus, a highly sensitive redox process was obtained that could follow the recognition process between the apatamer and the target. An amperometric variation of the naphthoquinone response was obtained regarding the ampicillin concentration with a limit of detection (LOD) of 10 pg/L (0.28 pM). A high selectivity towards other contaminants was demonstrated with this biosensor and the analysis of real river water samples without any treatment showed good recovery results thanks to the antifouling properties. This biosensor can be considered a promising device for the detection of antibiotics in the environment as a point-of-use system.

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Zhao, Dong Jiao, Yan Hong Chen, Chen Di Tu, Yao Fang Xuan, and Feng Na Xi. "Construction of Reagentless Biosensor Based on Self-Assembly and Electrodeposition for Determination of Hydrogen Peroxide." Advanced Materials Research 441 (January 2012): 442–46. http://dx.doi.org/10.4028/www.scientific.net/amr.441.442.

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A general methodology to prepare reagentless biosensor was developed based on self-assembly and electrodeposition. Redox active inorganic multilayers consisting of copper hexacyanoferrate (CuHCF) multilayers were formed by successive self-assembly. A simple and controllable electrodeposition approach was established for one-step fabrication of chitosan-enzyme layer on CuHCF modified electrode. Horseradish peroxidase was selected as the model enzyme. With CuHCF as the electroactive mediator, the developed reagentless biosensor exhibited a fast amperometric response for the determination of hydrogen peroxide (H2O2). The linear response ranged from 1.4 × 10-5 to 2.0 × 10-4 M with a detection limit of 1.2 × 10-6 M. The biosensor exhibited high reproducibility and long-time storage stability. The proposed methodology could serve as a versatile platform for fabrication of electrochemical biosensors.

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Lee, Yu-Jin, Da-Jung Chung, Sang-Hyub Oh, and Seong-Ho Choi. "Introduction of Bifunctional Group onto MWNT by Radiation-Induced Graft Polymerization and Its Use as Biosensor-Supporting Materials." Journal of Nanomaterials 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/127613.

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A biosensor comprisingtyrosinaseimmobilized on bifunctionalized multiwalled carbon nanotube (MWNT) supports was prepared for the detection of phenolic compounds in drinks such as red wine and juices. The MWNT supports were prepared by radiation-induced graft polymerization (RIGP) of epoxy-containing glycidyl methacrylate (GMA), to covalently immobilize thetyrosinase, and vinyl ferrocene (VF), which can act as an electron transfer mediator via redox reactions. The bifunctionalized MWNTs were characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA). Electrodes prepared with the MWNTs showed increased current with increasing VF content. A biosensor comprisingtyrosinaseimmobilized on the bifunctionalized MWNTs could detect phenol at 0.1–20 mM. Phenolics in red wine and juices were determined using the biosensor after its calibration.

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Antunes, Rafael Souza, Douglas Vieira Thomaz, Luane Ferreira Garcia, Eric de Souza Gil, and Flavio Marques Lopes. "Development and Optimization of Solanum Lycocarpum Polyphenol Oxidase-Based Biosensor and Application towards Paracetamol Detection." Advanced Pharmaceutical Bulletin 11, no. 3 (July 7, 2020): 469–76. http://dx.doi.org/10.34172/apb.2021.054.

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Purpose: The development biosensing technologies capable of delivering fast and reliable analysis is a growing trend in drug quality control. Considering the emerging use of plant-based polyphenol oxidases (PPO) as biological component of electrochemical biosensors, this work reports the first Solanum lycocarpum PPO biosensor and its use in the pharmaceutical analysis of paracetamol in tablet formulations. Methods: The biosensor was optimized regarding fruit maturation (immature and mature-ripe), vegetal extract volume to be used in biosensor construction as well as optimal pH of electrochemical cell fluid. Results: Results evidenced that the extract which rendered the biosensor with best analytical performance was from immature fruits, and the biosensor produced using 100 µL of crude plant extract promoted better faradaic signal gathering. Moreover, when neutral pH media was used in the electrochemical cell, the biosensor showcased best faradaic signal output from the used redox probe (catechol), suggesting thence that the method presents high sensibility for phenolic compounds detection. Furthermore, the biosensor was able to quantify paracetamol in a linear range from 50 to 300 μM, showcasing LoD and LoQ of 3 μM and 10 μM, respectively. Conclusion: after careful evaluation, this biosensor might be a low-cost alternative for conventional pharmaceutical quality control methods.

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Meyer, Andreas J., Thorsten Brach, Laurent Marty, Susanne Kreye, Nicolas Rouhier, Jean-Pierre Jacquot, and Rüdiger Hell. "Redox-sensitive GFP inArabidopsis thalianais a quantitative biosensor for the redox potential of the cellular glutathione redox buffer." Plant Journal 52, no. 5 (December 2007): 973–86. http://dx.doi.org/10.1111/j.1365-313x.2007.03280.x.

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Kafi, A. K. M., Dong-Yun Lee, Sang-Hyun Park, and Young-Soo Kwon. "A Hydrogen Peroxide Biosensor Based on Peroxidase Activity of Hemoglobin in Polymeric Film." Journal of Nanoscience and Nanotechnology 7, no. 11 (November 1, 2007): 4005–8. http://dx.doi.org/10.1166/jnn.2007.095.

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A Hydrogen peroxide (H2O2) biosensor, based on hemoglobin (Hb) and ortho-phenylenediamine (o-PD) gold electrode, was fabricated. Hb was immobilized onto the electrode surface by electrochemical polymerize method with o-PD. The designed biosensor showed a well defined redox peak which was attributed to the direct electrochemical response of Hb. The immobilized Hb exhibited an excellent electrocatalytical response to the reduction of hydrogen peroxide, enabling the sensitivity determination of H2O2. Factors and performances such as pH, potential, influencing the designed biosensor, were studied carefully. The amperometric detection of H2O2 was carried out at −300 mV in phosphate buffer solution (PBS) (0.1 M) with pH 6.0. This biosensor showed a fast amperometric response (less then 5 s) to H2O2. The levels of the (Relative standard deviation) RSDs (<3 5%) for the entire analyses reflected a highly reproducible sensor performance. Using the optimized conditions, the detection limit of the biosensor was 1 × 10−7 M and linear range was from 5 × 10−6 to 1.25 × 10−4 M. In addition, this sensor showed long term stability and good sensitivity.

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Villalonga, Anabel, Concepción Parrado, Raúl Díaz, Alfredo Sánchez, Beatriz Mayol, Paloma Martínez-Ruíz, Diana Vilela, and Reynaldo Villalonga. "Supramolecular Enzymatic Labeling for Aptamer Switch-Based Electrochemical Biosensor." Biosensors 12, no. 7 (July 12, 2022): 514. http://dx.doi.org/10.3390/bios12070514.

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Here we report a novel labeling strategy for electrochemical aptasensors based on enzymatic marking via supramolecular host–guest interactions. This approach relies on the use of an adamantane-modified target-responsive hairpin DNA aptamer as an affinity bioreceptor, and a neoglycoconjugate of β-cyclodextin (CD) covalently attached to a redox enzyme as a labeling element. As a proof of concept, an amperometric aptasensor for a carcinoembryonic antigen was assembled on screen-printed carbon electrodes modified with electrodeposited fern-like gold nanoparticles/graphene oxide and, by using a horseradish peroxidase-CD neoglycoenzyme as a biocatalytic redox label. This aptasensor was able to detect the biomarker in the concentration range from 10 pg/mL to 1 ng/mL with a high selectivity and a low detection limit of 3.1 pg/mL in human serum samples.

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Chaibun, Thanyarat, Patcharanin Thanasapburachot, Patutong Chatchawal, Lee Su Yin, Sirimanas Jiaranuchart, Patcharee Jearanaikoon, Chamras Promptmas, Waranun Buajeeb, and Benchaporn Lertanantawong. "A Multianalyte Electrochemical Genosensor for the Detection of High-Risk HPV Genotypes in Oral and Cervical Cancers." Biosensors 12, no. 5 (May 2, 2022): 290. http://dx.doi.org/10.3390/bios12050290.

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Infection with high-risk human papillomavirus (HPV) is a major risk factor for oral and cervical cancers. Hence, we developed a multianalyte electrochemical DNA biosensor that could be used for both oral and cervical samples to detect the high-risk HPV genotypes 16 and 18. The assay involves the sandwich hybridization of the HPV target to the silica-redox dye reporter probe and capture probe, followed by electrochemical detection. The sensor was found to be highly specific and sensitive, with a detection limit of 22 fM for HPV-16 and 20 fM for HPV-18, between the range of 1 fM and 1 µM. Evaluation with oral and cervical samples showed that the biosensor result was consistent with the nested PCR/gel electrophoresis detection. The biosensor assay could be completed within 90 min. Due to its simplicity, rapidity, and high sensitivity, this biosensor could be used as an alternative method for HPV detection in clinical laboratories as well as for epidemiological studies.

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Svintradze, David V., Darrell L. Peterson, Evys A. Collazo-Santiago, Janina P. Lewis, and H. Tonie Wright. "Structures of thePorphyromonas gingivalisOxyR regulatory domain explain differences in expression of the OxyR regulon inEscherichia coliandP. gingivalis." Acta Crystallographica Section D Biological Crystallography 69, no. 10 (September 20, 2013): 2091–103. http://dx.doi.org/10.1107/s0907444913019471.

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OxyR transcriptionally regulatesEscherichia colioxidative stress response genes through a reversibly reducible cysteine disulfide biosensor of cellular redox status. Structural changes induced by redox changes in these cysteines are conformationally transmitted to the dimer subunit interfaces, which alters dimer and tetramer interactions with DNA. In contrast toE. coliOxyR regulatory-domain structures, crystal structures ofPorphyromonas gingivalisOxyR regulatory domains show minimal differences in dimer configuration on changes in cysteine disulfide redox status. This locked configuration of theP. gingivalisOxyR regulatory-domain dimer closely resembles the oxidized (activating) form of theE. coliOxyR regulatory-domain dimer. It correlates with the observed constitutive activation of some oxidative stress genes inP. gingivalisand is attributable to a single amino-acid insertion inP. gingivalisOxyR relative toE. coliOxyR. Modelling of full-lengthP. gingivalis,E. coliandNeisseria meningitidisOxyR–DNA complexes predicts different modes of DNA binding for the reduced and oxidized forms of each.

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Srivastava, Monika, S. K. Srivastava, N. R. Nirala, and Rajiv Prakash. "A chitosan-based polyaniline–Au nanocomposite biosensor for determination of cholesterol." Anal. Methods 6, no. 3 (2014): 817–24. http://dx.doi.org/10.1039/c3ay41812j.

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Yagi-Utsumi, Maho, Haruko Miura, Christian Ganser, Hiroki Watanabe, Methanee Hiranyakorn, Tadashi Satoh, Takayuki Uchihashi, Koichi Kato, Kei-ichi Okazaki, and Kazuhiro Aoki. "Molecular Design of FRET Probes Based on Domain Rearrangement of Protein Disulfide Isomerase for Monitoring Intracellular Redox Status." International Journal of Molecular Sciences 24, no. 16 (August 16, 2023): 12865. http://dx.doi.org/10.3390/ijms241612865.

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Multidomain proteins can exhibit sophisticated functions based on cooperative interactions and allosteric regulation through spatial rearrangements of the multiple domains. This study explored the potential of using multidomain proteins as a basis for Förster resonance energy transfer (FRET) biosensors, focusing on protein disulfide isomerase (PDI) as a representative example. PDI, a well-studied multidomain protein, undergoes redox-dependent conformational changes, enabling the exposure of a hydrophobic surface extending across the b’ and a’ domains that serves as the primary binding site for substrates. Taking advantage of the dynamic domain rearrangements of PDI, we developed FRET-based biosensors by fusing the b’ and a’ domains of thermophilic fungal PDI with fluorescent proteins as the FRET acceptor and donor, respectively. Both experimental and computational approaches were used to characterize FRET efficiency in different redox states. In vitro and in vivo evaluations demonstrated higher FRET efficiency of this biosensor in the oxidized form, reflecting the domain rearrangement and its responsiveness to intracellular redox environments. This novel approach of exploiting redox-dependent domain dynamics in multidomain proteins offers promising opportunities for designing innovative FRET-based biosensors with potential applications in studying cellular redox regulation and beyond.

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Deng, Ying, Zuorui Wen, Guiling Luo, Hui Xie, Juan Liu, Yaru Xi, Guangjiu Li, and Wei Sun. "Carbon Nitride Nanosheet and Myoglobin Modified Electrode for Electrochemical Sensing Investigations." Current Analytical Chemistry 16, no. 6 (August 13, 2020): 703–10. http://dx.doi.org/10.2174/1573411015666190710223818.

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Background: Carbon-based nanomaterials, especially carbon nitride (C3N4) has attracted tremendous interest in biosensor applications. Meanwhile, the mechanism of redox protein sensing and related electrocatalytic reactions can provide a valid basis for understanding the process of biological redox reaction. Objective: The aim of this paper is to construct a new electrochemical enzyme sensor to achieve direct electron transfer of myoglobin (Mb) on CILE surface and display electrocatalytic reduction activity to catalyze trichloroacetic acid (TCA) and H2O2. Methods: The working electrode was fabricated based on ionic liquid modified Carbon Paste Electrode (CILE) and C3N4 nanosheets were modified on the CILE surface, then Mb solution was fixed on C3N4/CILE surface and immobilized by using Nafion film. The as-prepared biosensor displayed satisfactory electrocatalytic ability towards the reduction of TCA and H2O2 in an optimum pH 7.0 buffer solution. Results: The results indicated that C3N4 modified electrode retained the activity of the enzyme and displayed quasi-reversible redox behavior in an optimum pH 7.0 buffer solution. The electrochemical parameters of the immobilized Mb on the electrode surface were further calculated with the results of the electron transfer number (n) as 1.27, the charge transfer coefficient (α) as 0.53 and the electrontransfer rate constant (ks) as 3.32 s-1, respectively. The Nafion/Mb/C3N4/CILE displayed outstanding electrocatalytic reduction activity to catalyze trichloroacetic acid and H2O2. Conclusion: The Nafion/Mb/C3N4/CILE displayed outstanding electrocatalytic reduction, which demonstrated the promising applications of C3N4 nanosheet in the field electrochemical biosensing.

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Negahdary, Masoud, Saeed Rezaei-Zarchi, Neda Rousta, and Soheila Samei Pour. "Direct Electron Transfer of Cytochrome c on ZnO Nanoparticles Modified Carbon Paste Electrode." ISRN Biophysics 2012 (March 25, 2012): 1–6. http://dx.doi.org/10.5402/2012/937265.

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The direct electrochemistry of cytochrome c (cyt c) immobilized on a modified carbon paste electrode (CPE) was described. The electrode was modified with ZnO nanoparticles. Direct electrochemistry of cytochrome c in this paste electrode was easily achieved, and a pair of well-defined quasireversible redox peaks of a heme Fe (III)/Fe(II) couple appeared with a formal potential (E0) of −0.303 V (versus SCE) in pH 7.0 phosphate buffer solution (PBS). The fabricated modified bioelectrode showed good electrocatalytic ability for reduction of H2O2. The preparation process of the proposed biosensor was convenient, and the resulting biosensor showed high sensitivity, low detection limit, and good stability.

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Baluta, Sylwia, Marta Romaniec, Kinga Halicka-Stępień, Michalina Alicka, Aleksandra Pieła, Katarzyna Pala, and Joanna Cabaj. "A Novel Strategy for Selective Thyroid Hormone Determination Based on an Electrochemical Biosensor with Graphene Nanocomposite." Sensors 23, no. 2 (January 5, 2023): 602. http://dx.doi.org/10.3390/s23020602.

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This article presents a novel and selective electrochemical bioassay with antibody and laccase for the determination of free thyroid hormone (free triiodothyronine, fT3). The biosensor was based on a glassy carbon electrode modified with a Fe3O4@graphene nanocomposite with semiconducting properties, an antibody (anti-PDIA3) with high affinity for fT3, and laccase, which was responsible for catalyzing the redox reaction of fT3. The electrode modification procedure was investigated using a cyclic voltammetry technique, based on the response of the peak current after modifications. All characteristic working parameters of the developed biosensor were analyzed using differential pulse voltammetry. Obtained experimental results showed that the biosensor revealed a sensitive response to fT3 in a concentration range of 10–200 µM, a detection limit equal to 27 nM, and a limit of quantification equal to 45.9 nM. Additionally, the constructed biosensor was selective towards fT3, even in the presence of interference substances: ascorbic acid, tyrosine, and levothyroxine, and was applied for the analysis of fT3 in synthetic serum samples with excellent recovery results. The designed biosensor also exhibited good stability and can find application in future medical diagnostics.

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Kreindl, Christine, Sandra A. Soto-Alarcón, Miltha Hidalgo, Ana L. Riveros, Carolina Añazco, Rodrigo Pulgar, and Omar Porras. "Selenium Compounds Affect Differently the Cytoplasmic Thiol/Disulfide State in Dermic Fibroblasts and Improve Cell Migration by Interacting with the Extracellular Matrix." Antioxidants 13, no. 2 (January 26, 2024): 159. http://dx.doi.org/10.3390/antiox13020159.

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Deficient wound healing is frequently observed in patients diagnosed with diabetes, a clinical complication that compromises mobility and leads to limb amputation, decreasing patient autonomy and family lifestyle. Fibroblasts are crucial for secreting the extracellular matrix (ECM) to pave the wound site for endothelial and keratinocyte regeneration. The biosynthetic pathways involved in collagen production and crosslinking are intimately related to fibroblast redox homeostasis. In this study, two sets of human dermic fibroblasts were cultured in normal (5 mM) and high (25 mM)-glucose conditions in the presence of 1 µM selenium, as sodium selenite (inorganic) and the two selenium amino acids (organic), Se-cysteine and Se-methionine, for ten days. We investigated the ultrastructural changes in the secreted ECM induced by these conditions using scanning electron microscopy (SEM). In addition, we evaluated the redox impact of these three compounds by measuring the basal state and real-time responses of the thiol-based HyPer biosensor expressed in the cytoplasm of these fibroblasts. Our results indicate that selenium compound supplementation pushed the redox equilibrium towards a more oxidative tone in both sets of fibroblasts, and this effect was independent of the type of selenium. The kinetic analysis of biosensor responses allowed us to identify Se-cysteine as the only compound that simultaneously improved the sensitivity to oxidative stimuli and augmented the disulfide bond reduction rate in high-glucose-cultured fibroblasts. The redox response profiles showed no clear association with the ultrastructural changes observed in matrix fibers secreted by selenium-treated fibroblasts. However, we found that selenium supplementation improved the ECM secreted by high-glucose-cultured fibroblasts according to endothelial migration assessed with a wound healing assay. Direct application of sodium selenite and Se-cysteine on purified collagen fibers subjected to glycation also improved cellular migration, suggesting that these selenium compounds avoid the undesired effect of glycation.

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Stoikov, Dmitry, Alexey Ivanov, Insiya Shafigullina, Milena Gavrikova, Pavel Padnya, Igor Shiabiev, Ivan Stoikov, and Gennady Evtugyn. "Flow-Through Amperometric Biosensor System Based on Functionalized Aryl Derivative of Phenothiazine and PAMAM-Calix-Dendrimers for the Determination of Uric Acid." Biosensors 14, no. 3 (February 23, 2024): 120. http://dx.doi.org/10.3390/bios14030120.

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A flow-through biosensor system for the determination of uric acid was developed on the platform of flow-through electrochemical cell manufactured by 3D printing from poly(lactic acid) and equipped with a modified screen-printed graphite electrode (SPE). Uricase was immobilized to the inner surface of a replaceable reactor chamber. Its working volume was reduced to 10 μL against a previously reported similar cell. SPE was modified independently of the enzyme reactor with carbon black, pillar[5]arene, poly(amidoamine) dendrimers based on the p-tert-butylthiacalix[4]arene (PAMAM-calix-dendrimers) platform and electropolymerized 3,7-bis(4-aminophenylamino) phenothiazin-5-ium chloride. Introduction of the PAMAM-calix-dendrimers into the electrode coating led to a fivefold increase in the redox currents of the electroactive polymer. It was found that higher generations of the PAMAM-calix-dendrimers led to a greater increase in the currents measured. Coatings consisted of products of the electropolymerization of the phenothiazine with implemented pillar[5]arene and PAMAM-calix-dendrimers showing high efficiency in the electrochemical reduction of hydrogen peroxide that was formed in the enzymatic oxidation of uric acid. The presence of PAMAM-calix-dendrimer G2 in the coating increased the redox signal related to the uric acid assay by more than 1.5 times. The biosensor system was successfully applied for the enzymatic determination of uric acid in chronoamperometric mode. The following optimal parameters for the chronoamperometric determination of uric acid in flow-through conditions were established: pH 8.0, flow rate 0.2 mL·min−1, 5 U of uricase per reactor. Under these conditions, the biosensor system made it possible to determine from 10 nM to 20 μM of uric acid with the limit of detection (LOD) of 4 nM. Glucose (up to 1 mM), dopamine (up to 0.5 mM), and ascorbic acid (up to 50 μM) did not affect the signal of the biosensor toward uric acid. The biosensor was tested on spiked artificial urine samples, and showed 101% recovery for tenfold diluted samples. The ease of assembly of the flow cell and the low cost of the replacement parts make for a promising future application of the biosensor system in routine clinical analyses.

Journal articles on the topic 'Biosenseur redox'

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