Journal articles: 'Conjugated Biomolecules'

1

Wang, Jian, Ting Ting Wang, Peng Fei Gao, and Cheng Zhi Huang. "Biomolecules-conjugated nanomaterials for targeted cancer therapy." J. Mater. Chem. B 2, no. 48 (2014): 8452–65. http://dx.doi.org/10.1039/c4tb01263a.

Full text

Abstract:

Now and in the future, with the development of artificial biomolecules as well as nanomaterials, targeted drug delivery based on elegant biomolecule–nanomaterial conjugation approaches is being developed to achieve great versatility, additional functions, and further advances.

APA, Harvard, Vancouver, ISO, and other styles

2

Park, Sinwook, Keren Buhnik-Rosenblau, Ramadan Abu-Rjal, Yechezkel Kashi, and Gilad Yossifon. "Periodic concentration–polarization-based formation of a biomolecule preconcentrate for enhanced biosensing." Nanoscale 12, no. 46 (2020): 23586–95. http://dx.doi.org/10.1039/d0nr05930g.

Full text

Abstract:

Periodic concentration–polarization-based formation of a preconcentrated biomolecule plug using the sandwich immunoassay approach, wherein the target biomolecules bind between immobilized magnetic bead-conjugated antibodies and reporter antibodies.

APA, Harvard, Vancouver, ISO, and other styles

3

Abes, S., H. Moulton, J. Turner, P. Clair, J. P. Richard, P. Iversen, M. J. Gait, and B. Lebleu. "Peptide-based delivery of nucleic acids: design, mechanism of uptake and applications to splice-correcting oligonucleotides." Biochemical Society Transactions 35, no. 1 (January 22, 2007): 53–55. http://dx.doi.org/10.1042/bst0350053.

Full text

Abstract:

CPPs (cell-penetrating peptides) have given rise to much interest for the delivery of biomolecules such as peptides, proteins or ONs (oligonucleotides). CPPs and their conjugates were initially thought to translocate through the cell membrane by a non-endocytotic mechanism which has recently been re-evaluated. Basic-amino-acid-rich CPPs first interact with cell-surface proteoglycans before being internalized by endocytosis. Sequestration and degradation in endocytotic vesicles severely limits the cytoplasmic and nuclear delivery of the conjugated biomolecules. Accordingly, splicing correction by CPP-conjugated steric-block ON analogues is inefficient in the absence of endosomolytic agents. New arginine-rich CPPs allowing efficient splicing correction by conjugated PNAs (peptide nucleic acids) or PMO (phosphorodiamidate morpholino oligomer) steric blockers in the absence of endosomolytic agents have recently been defined in our group and are currently being characterized. They offer promising leads for the development of efficient cellular delivery vectors for therapeutic steric-block ON analogues.

APA, Harvard, Vancouver, ISO, and other styles

4

Ni, Jielei, Bo Cao, Gang Niu, Danni Chen, Guotao Liang, Tingying Xia, Heng Li, et al. "Improved localization precision via restricting confined biomolecule stochastic motion in single-molecule localization microscopy." Nanophotonics 11, no. 1 (November 16, 2021): 53–65. http://dx.doi.org/10.1515/nanoph-2021-0481.

Full text

Abstract:

Abstract Single-molecule localization microscopy (SMLM) plays an irreplaceable role in biological studies, in which nanometer-sized biomolecules are hardly to be resolved due to diffraction limit unless being stochastically activated and accurately located by SMLM. For biological samples preimmobilized for SMLM, most biomolecules are cross-linked and constrained at their immobilizing sites but still expected to undergo confined stochastic motion in regard to their nanometer sizes. However, few lines of direct evidence have been reported about the detectability and influence of confined biomolecule stochastic motion on localization precision in SMLM. Here, we access the potential stochastic motion for each immobilized single biomolecule by calculating the displacements between any two of its localizations at different frames during sequential imaging of Alexa Fluor-647-conjugated oligonucleotides. For most molecules, localization displacements are remarkably larger at random frame intervals than at shortest intervals even after sample drift correction, increase with interval times and then saturate, showing that biomolecule stochastic motion is detected and confined around the immobilizing sizes in SMLM. Moreover, localization precision is inversely proportional to confined biomolecule stochastic motion, whereas it can be deteriorated or improved by enlarging the biomolecules or adding a post-crosslinking step, respectively. Consistently, post-crosslinking of cell samples sparsely stained for tubulin proteins results in a better localization precision. Overall, this study reveals that confined stochastic motion of immobilized biomolecules worsens localization precision in SMLM, and improved localization precision can be achieved via restricting such a motion.

APA, Harvard, Vancouver, ISO, and other styles

5

Katas, Haliza, Nik Nur Shamiha Nik Dzulkefli, and Shariza Sahudin. "Synthesis of a New Potential Conjugated TAT-Peptide-Chitosan Nanoparticles Carrier via Disulphide Linkage." Journal of Nanomaterials 2012 (2012): 1–7. http://dx.doi.org/10.1155/2012/134607.

Full text

Abstract:

Chitosan and TAT peptide have been widely investigated as delivery systems for various biomolecules such as plasmid DNA, oligonucleotides, and siRNAs. Conjugation of chitosan with TAT-peptide was therefore expected to produce a carrier with enhanced ability to facilitate cellular uptake. In this study, chitosan nanoparticles (CNs) were prepared by ionic gelation method prior to conjugation with TAT-peptide via disulphide linkage (CN-TAT). The conjugation was performed at various TAT-peptide-to-chitosan weight ratios ranging from 0.008 : 1 to 0.125 : 1. siRNA as a model biomolecule was loaded by adsorption onto the CN-TAT. Nanosize range particles were produced with a size range of less than 700 nm depending on TAT-peptide concentration used. HPLC and Raman spectrometry analysis revealed that TAT-peptide was successfully conjugated to the CN via disulphide linkage. siRNA loading efficiency for CN-TAT was 93% ±0.01.In vitrocytotoxicity studies showed that CN-TAT has relatively low toxicity. In conclusion, TAT conjugated onto CN via disulphide linkage was successfully synthesized, and its low cytoxicity demonstrates a potential for its use as a vector for biomolecules.

APA, Harvard, Vancouver, ISO, and other styles

6

Higashi, Sayuri L., Normazida Rozi, Sharina Abu Hanifah, and Masato Ikeda. "Supramolecular Architectures of Nucleic Acid/Peptide Hybrids." International Journal of Molecular Sciences 21, no. 24 (December 12, 2020): 9458. http://dx.doi.org/10.3390/ijms21249458.

Full text

Abstract:

Supramolecular architectures that are built artificially from biomolecules, such as nucleic acids or peptides, with structural hierarchical orders ranging from the molecular to nano-scales have attracted increased attention in molecular science research fields. The engineering of nanostructures with such biomolecule-based supramolecular architectures could offer an opportunity for the development of biocompatible supramolecular (nano)materials. In this review, we highlighted a variety of supramolecular architectures that were assembled from both nucleic acids and peptides through the non-covalent interactions between them or the covalently conjugated molecular hybrids between them.

APA, Harvard, Vancouver, ISO, and other styles

7

Khatchadourian, Rafael, Alexia Bachir, Samuel J. Clarke, Colin D. Heyes, Paul W. Wiseman, and Jay L. Nadeau. "Fluorescence Intensity and Intermittency as Tools for Following Dopamine Bioconjugate Processing in Living Cells." Journal of Biomedicine and Biotechnology 2007 (2007): 1–10. http://dx.doi.org/10.1155/2007/70145.

Full text

Abstract:

CdSe/ZnS quantum dots (QDs) conjugated to biomolecules that quench their fluorescence, particularly dopamine, have particular spectral properties that allow determination of the number of conjugates per particle, namely, photoenhancement and photobleaching. In this work, we quantify these properties on a single-particle and ensemble basis in order to evaluate their usefulness as a tool for indicating QD uptake, breakdown, and processing in living cells. This creates a general framework for the use of fluorescence quenching and intermittency to better understand nanoparticle-cell interactions.

APA, Harvard, Vancouver, ISO, and other styles

8

Zhuravlova, Maryna, Nataliya Obernikhina, Stepan Pilyo, Maryna Kachaeva, Oleksiy Kachkovsky, and Volodymyr Brovarets. "In silico binding affinity studies of phenyl-substituted 1,3-oxazoles with protein molecules." Ukr. Bioorg. Acta 2020, Vol. 15, N1 15, no. 1 (June 30, 2020): 12–19. http://dx.doi.org/10.15407/bioorganica2020.01.012.

Full text

Abstract:

The new model approach of interaction between the pharmacophores with bio-molecules, fragment-to-fragment, is presented. It is a new step of the molecular modeling and takes correctly into consideration not only the spatial complementarity of the interacted molecules but also the contribution of the stacking π-π-electron interaction and hydrogen bonds. As an example, the correct analysis of the interaction of the biological active phenyl-substituted 1,3-oxazoles with protein fragments is performed. It was shown that the length and energy of the hydrogen bond uniquely depend on the chemical constitution of both components in the created complex [Pharmacophore(Oxazole)-Biomolecule (H-X)]. The binding energy regularly decreases in the series X → O, S, NH (fragments of the corresponding biomolecules). It should be pointed out that introduction of the conjugated phenyl groups at positions 2 and 5 of oxazoles increase the stability of the possibly generated complex Pharmacophore-Biomolecule [Pharm-BioM] with fragments of the corresponding biomolecules along the core of oxazole by 0.2 and 0.5 kcal/mole. At the same time, modeling of the possibly generated complex [Pharm-BioM] by phenyl substituents at position 2 and 5 of 1,3-oxazole with phenylalanine as a fragment of protein molecules additionally stabilizes complex by 2.5 kcal/mole by π-stacking mechanism. It seems, the observed biological activity of the phenyl substituted 1,3-oxazole is rather connected with the possibility to generate the stable complex due to the formation of additional bonds with other fragments (conjugated phenyl core). The calculations give that such substituents do not cause spatial hindrances with the polypeptide chain.

APA, Harvard, Vancouver, ISO, and other styles

9

McKenzie, Fiona, Victoria Steven, Andrew Ingram, and Duncan Graham. "Quantitation of biomolecules conjugated to nanoparticles by enzyme hydrolysis." Chemical Communications, no. 20 (2009): 2872. http://dx.doi.org/10.1039/b823057a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Yang, Meng, Susan Hoppmann, Luxi Chen, and Zhen Cheng. "Human Serum Albumin Conjugated Biomolecules for Cancer Molecular Imaging." Current Pharmaceutical Design 18, no. 8 (March 1, 2012): 1023–31. http://dx.doi.org/10.2174/138161212799315830.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Mekonnen, Tessema, Ulrich Panne, and Matthias Koch. "Glucosylation and Glutathione Conjugation of Chlorpyrifos and Fluopyram Metabolites Using Electrochemistry/Mass Spectrometry." Molecules 24, no. 5 (March 4, 2019): 898. http://dx.doi.org/10.3390/molecules24050898.

Full text

Abstract:

Xenobiotics and their reactive metabolites are conjugated with native biomolecules such as glutathione and glucoside during phase II metabolism. Toxic metabolites are usually detoxified during this step. On the other hand, these reactive species have a potential health impact by disrupting many enzymatic functions. Thus, it is crucial to understand phase II conjugation reactions of xenobiotics in order to address their fate and possible toxicity mechanisms. Additionally, conventional methods (in vivo and in vitro) have limitation due to matrix complexity and time-consuming. Hence, developing fast and matrix-free alternative method is highly demandable. In this work, oxidative phase I metabolites and reactive species of chlorpyrifos (insecticide) and fluopyram (fungicide) were electrochemically produced by using a boron-doped diamond electrode coupled online to electrospray mass spectrometry (ESI-MS). Reactive species of the substrates were trapped by biomolecules (glutathione and glucoside) and phase II conjugative metabolites were identified using liquid chromatography (LC)-MS/MS, and/or Triple time of flight (TripleTOF)-MS. Glutathione conjugates and glucosylation of chlorpyrifos, trichloropyridinol, oxon, and monohydroxyl fluopyram were identified successfully. Glutathione and glucoside were conjugated with chlorpyrifos, trichloropyridinol, and oxon by losing a neutral HCl. In the case of fluopyram, its monohydroxyl metabolite was actively conjugated with both glutathione and glucoside. In summary, seven bioconjugates of CPF and its metabolites and two bioconjugates of fluopyram metabolites were identified using electrochemistry (EC)/MS for the first time in this work. The work could be used as an alternative approach to identify glutathione and glucosylation conjugation reactions of other organic compounds too. It is important, especially to predict phase II conjugation within a short time and matrix-free environment.

APA, Harvard, Vancouver, ISO, and other styles

12

Tang, Wen, and Matthew L. Becker. "“Click” reactions: a versatile toolbox for the synthesis of peptide-conjugates." Chem. Soc. Rev. 43, no. 20 (2014): 7013–39. http://dx.doi.org/10.1039/c4cs00139g.

Full text

Abstract:

Peptides that comprise the functional subunits of proteins have been conjugated to versatile materials (biomolecules, polymers, surfaces and nanoparticles) in an effort to modulate cell responses, specific binding affinity and/or self-assembly behavior.

APA, Harvard, Vancouver, ISO, and other styles

13

Reisbeck, Felix, Stefanie Wedepohl, Mathias Dimde, Ann-Cathrin Schmitt, Jens Dernedde, Miguel Álvaro-Benito, Christian Freund, and Rainer Haag. "Synthesis and functionalization of dendritic polyglycerol-based nanogels: application in T cell activation." Journal of Materials Chemistry B 10, no. 1 (2022): 96–106. http://dx.doi.org/10.1039/d1tb02144c.

Full text

Abstract:

Synthesis of a dPG- and NG-based nanoplatform conjugated to avidin for the multivalent display of biotinylated biomolecules. Carriers were coupled to antibodies and their capability to activate T cells was assessed, showing a multivalency effect.

APA, Harvard, Vancouver, ISO, and other styles

14

Mendoza-Nava, Héctor, Guillermina Ferro-Flores, Flor de María Ramírez, Blanca Ocampo-García, Clara Santos-Cuevas, Liliana Aranda-Lara, Erika Azorín-Vega, Enrique Morales-Avila, and Keila Isaac-Olivé. "177Lu-Dendrimer Conjugated to Folate and Bombesin with Gold Nanoparticles in the Dendritic Cavity: A Potential Theranostic Radiopharmaceutical." Journal of Nanomaterials 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/1039258.

Full text

Abstract:

177Lu-labeled nanoparticles conjugated to biomolecules have been proposed as a new class of theranostic radiopharmaceuticals. The aim of this research was to synthesize 177Lu-dendrimer(PAMAM-G4)-folate-bombesin with gold nanoparticles (AuNPs) in the dendritic cavity and to evaluate the radiopharmaceutical potential for targeted radiotherapy and the simultaneous detection of folate receptors (FRs) and gastrin-releasing peptide receptors (GRPRs) overexpressed in breast cancer cells. p-SCN-Benzyl-DOTA was conjugated in aqueous-basic medium to the dendrimer. The carboxylate groups of Lys1Lys3(DOTA)-bombesin and folic acid were activated with HATU and also conjugated to the dendrimer. The conjugate was mixed with 1% HAuCl4 followed by the addition of NaBH4 and purified by ultrafiltration. Elemental analysis (EDS), particle size distribution (DLS), TEM analysis, UV-Vis, and infrared and fluorescence spectroscopies were performed. The conjugate was radiolabeled using 177LuCl3 or 68GaCl3 and analyzed by radio-HPLC. Studies confirmed the dendrimer functionalization with high radiochemical purity (>95%). Fluorescence results demonstrated that the presence of AuNPs in the dendritic cavity confers useful photophysical properties to the radiopharmaceutical for optical imaging. Preliminary binding studies in T47D breast cancer cells showed a specific cell uptake (41.15±2.72%). 177Lu-dendrimer(AuNP)-folate-bombesin may be useful as an optical and nuclear imaging agent for breast tumors overexpressing GRPR and FRs, as well as for targeted radiotherapy.

APA, Harvard, Vancouver, ISO, and other styles

15

Mochizuki, Masahito, Shinichi Sato, Syifa Asatyas, Zbigniew J. Leśnikowski, Tomohiro Hayashi, and Hiroyuki Nakamura. "Raman cell imaging with boron cluster molecules conjugated with biomolecules." RSC Advances 9, no. 41 (2019): 23973–78. http://dx.doi.org/10.1039/c9ra04228h.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Li, Taihua, Hyun Gyu Park, Hee-Seung Lee, and Seong-Ho Choi. "Circular dichroism study of chiral biomolecules conjugated with silver nanoparticles." Nanotechnology 15, no. 10 (August 21, 2004): S660—S663. http://dx.doi.org/10.1088/0957-4484/15/10/026.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Torchynska, T. V., G. Polupan, and L. G. Vega Macotela. "Emission transformation in CdSe/ZnS quantum dots conjugated to biomolecules." Journal of Photochemistry and Photobiology B: Biology 170 (May 2017): 309–13. http://dx.doi.org/10.1016/j.jphotobiol.2017.04.012.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Molavipordanjani, Sajjad, and Seyed Jalal Hosseinimehr. "Strategies for Conjugation of Biomolecules to Nanoparticles as Tumor Targeting Agents." Current Pharmaceutical Design 25, no. 37 (December 17, 2019): 3917–26. http://dx.doi.org/10.2174/1381612825666190903154847.

Full text

Abstract:

Combination of nanotechnology, biochemistry, chemistry and biotechnology provides the opportunity to design unique nanoparticles for tumor targeting, drug delivery, medical imaging and biosensing. Nanoparticles conjugated with biomolecules such as antibodies, peptides, vitamins and aptamer can resolve current challenges including low accumulation, internalization and retention at the target site in cancer diagnosis and therapy through active targeting. In this review, we focus on different strategies for conjugation of biomolecules to nanoparticles such as inorganic nanoparticles (iron oxide, gold, silica and carbon nanoparticles), liposomes, lipid and polymeric nanoparticles and their application in tumor targeting.

APA, Harvard, Vancouver, ISO, and other styles

19

Murei, A., K. Pillay, and A. Samie. "Syntheses, Characterization, and Antibacterial Evaluation of P. grandiflora Extracts Conjugated with Gold Nanoparticles." Journal of Nanotechnology 2021 (December 24, 2021): 1–10. http://dx.doi.org/10.1155/2021/8687627.

Full text

Abstract:

Background. With the recent increase in antibiotic resistance to conventional antibiotics, gold nanoparticles, and medicinal plants, extracts present an interesting alternative. Objectives. This study aimed to synthesize, characterize, and evaluate Pyrenacantha grandiflora Baill extracts and gold nanoparticle conjugates against pathogenic bacteria. Methods. We synthesized gold nanoparticles by chemical and biological methods. The nanoparticles were characterized by the use of UV-visible spectrophotometry, followed by transmission electron microscopy (TEM) and energy-dispersive X-ray analysis (EDX). Gold nanoparticles were conjugated to plant extracts and analyzed with a Fourier-transform infrared spectroscope (FTIR). We determined the antimicrobial activity of the conjugates using well diffusion and the microdilution assays. Results. The UV–visible spectra of gold nanoparticles showed a synthesis peak at 530 nm. FTIR analysis indicated functional biomolecules that were associated with plant extract conjugated gold nanoparticles; the formation of C–H group and carbonyl (C=O) groups, –OH carbonyl, and C≡C groups were also observed. Biologically synthesized nanoparticles were star-shaped when observed by TEM with an average size of 11 nm. Gold nanoparticles synthesized with P. grandiflora water extracts showed the largest zone of inhibition (22 mm). When the gold nanoparticles synthesized by the biological method were conjugated with acetone extracts of P. grandiflora, MIC as low as 0.0063 mg/mL was observed against beta-lactamase producing K. pneumonia. The activity of acetone extracts was improved with chemically synthesized gold nanoparticles particularly when beta-lactamase producing E. coli and MRSA were used as test organisms. A synergistic effect was observed against all tested bacteria, except for MRSA when gold nanoparticles were conjugated with acetone extract. Conclusion. Overall, P. grandiflora tuber extracts conjugated with gold nanoparticles showed a very good antibacterial activity that improved both plant extract and gold nanoparticle’s individual activity.

APA, Harvard, Vancouver, ISO, and other styles

20

Kim, Soojung, Hyerin Song, Heesang Ahn, Seung Won Jun, Seungchul Kim, Young Min Song, Seung Yun Yang, Chang-Seok Kim, and Kyujung Kim. "3D super-resolved imaging in live cells using sub-diffractive plasmonic localization of hybrid nanopillar arrays." Nanophotonics 9, no. 9 (May 23, 2020): 2847–59. http://dx.doi.org/10.1515/nanoph-2020-0105.

Full text

Abstract:

AbstractAnalysing dynamics of a single biomolecule using high-resolution imaging techniques has been had significant attentions to understand complex biological system. Among the many approaches, vertical nanopillar arrays in contact with the inside of cells have been reported as a one of useful imaging applications since an observation volume can be confined down to few-tens nanometre theoretically. However, the nanopillars experimentally are not able to obtain super-resolution imaging because their evanescent waves generate a high optical loss and a low signal-to-noise ratio. Also, conventional nanopillars have a limitation to yield 3D information because they do not concern field localization in z-axis. Here, we developed novel hybrid nanopillar arrays (HNPs) that consist of SiO2 nanopillars terminated with gold nanodisks, allowing extreme light localization. The electromagnetic field profiles of HNPs are obtained through simulations and imaging resolution of cell membrane and biomolecules in living cells are tested using one-photon and 3D multiphoton fluorescence microscopy, respectively. Consequently, HNPs present approximately 25 times enhanced intensity compared to controls and obtained an axial and lateral resolution of 110 and 210 nm of the intensities of fluorophores conjugated with biomolecules transported in living cells. These structures can be a great platform to analyse complex intracellular environment.

APA, Harvard, Vancouver, ISO, and other styles

21

Farinola, Gianluca M., Francesco Babudri, Antonio Cardone, Omar Hassan Omar, and Francesco Naso. "Synthesis of substituted conjugated polymers: Tuning properties by functionalization." Pure and Applied Chemistry 80, no. 8 (January 1, 2008): 1735–46. http://dx.doi.org/10.1351/pac200880081735.

Full text

Abstract:

The review addresses features of special interest concerning two classes of functionalized semiconducting polymers: poly(aryleneethynylene)s (PAEs) bearing biomolecules as chiral nonracemic pendant groups and poly(phenylenevinylene)s (PPVs), which are fluorinated in various positions of the repeating units. Molecular design and choice of specific substituents, synthetic protocols, and the effect of functionalization on properties of the polymers both in solution and in the solid state are discussed.

APA, Harvard, Vancouver, ISO, and other styles

22

Jiménez-Balsa, Adrián, Sandra Pinto, Emanuel Quartin, Miguel M. Lino, Vitor Francisco, and Lino Ferreira. "Nanoparticles Conjugated with Photocleavable Linkers for the Intracellular Delivery of Biomolecules." Bioconjugate Chemistry 29, no. 5 (April 13, 2018): 1485–89. http://dx.doi.org/10.1021/acs.bioconjchem.7b00820.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Wang, Li Yong, Yuan Yuan Han, Yu Ding, Bo Na Li, and Chao Shan Liu. "Application of Carbon Nanoparticles as Fluorescent Quenchors in Biochemistry." Advanced Materials Research 998-999 (July 2014): 187–90. http://dx.doi.org/10.4028/www.scientific.net/amr.998-999.187.

Full text

Abstract:

carbon nanoparticles (CNPs ) prepared by electrochemical oxidation method possesses high surface activities, and based on strong affinities between water-soluble CNPs and fluorescent molecules, the mechanisms of fluorescence quenching towards Conjugated Polymers (CPs) was discussed, and CNPs could acted as a nanoquenchor for biochemistry application, such as detection of DNA molecules and other biomolecules by the similar way.

APA, Harvard, Vancouver, ISO, and other styles

24

Pillai, Sreenadh Sasidharan, Hiroshi Yukawa, Daisuke Onoshima, Vasudevanpillai Biju, and Yoshinobu Baba. "Quantum Dot-Peptide Nanoassembly on Mesoporous Silica Nanoparticle for Biosensing." Nano Hybrids and Composites 19 (February 2018): 55–72. http://dx.doi.org/10.4028/www.scientific.net/nhc.19.55.

Full text

Abstract:

Quantum dots (QDs) are powerful luminescent probes for detecting single-molecules and imaging live cells. Despite several reports on bioimaging and biosensing applications of QDs, controlled and targeted detection of biomolecules using quantum dots is an ongoing challenge. When a QD is conjugated with an ideal chromophore, which can be a fluorescent or a non-fluorescent dye molecule, QD luminescence can be quenched by Förster resonance energy transfer (FRET) to the quencher dye. However, the photoluminescence of QD can be recovered upon on-demand release of the quencher. Our study focuses on quenching of QD photoluminescence after conjugation with a non-fluorescent dye molecule, black hole quencher 1 (BHQ-1), intermediated with a molecular sensing target peptide GPLG↓VRGK. Based on steady-state and time-resolved photoluminescence measurements of QD and the QD-peptide-BHQ-1 sensor assemblies, we attribute the quenching of photoluminescence intensity and lifetime to FRET from the QD to BHQ-1molecules. Here the intermediate peptide GPLG↓VRGK can be cleaved by matrix metalloproteinase-2 (MMP-2), an enzyme that is upregulated in cancer cells extra cellular matrix (ECM), at its Gly and Val region shown by the down headed arrow. Here the QD-pep-BHQ-1 conjugate detected the MMP-2 presence at the extra cellular matrix of H1299 cancer cells. Further the QD-pep-BHQ-1 molecules were conjugated at the surface of a mesoporous silica nanoparticle (MSN) scaffold to localize maximum target peptide in a nanospace volume for the future αvβ3 integrin receptor targeted detection of MMP-2. The luminescence quenching of MSN-QD-pep-BHQ-1 conjugates were analyzed with time resolved photoluminescence measurement.

APA, Harvard, Vancouver, ISO, and other styles

25

Mahle, Reddhy, Debabrata Mandal, Partha Kumbhakar, Amreesh Chandra, Chandra Sekhar Tiwary, and Rintu Banerjee. "A study of microbially fabricated bio-conjugated quantum dots for pico-molar sensing of H2O2 and glucose." Biomaterials Science 9, no. 1 (2021): 157–66. http://dx.doi.org/10.1039/d0bm01206h.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Chiu, Chen-Feng, Ru-Huei Fu, Shan-hui Hsu, Yang-Hao (Alex) Yu, Shun-Fa Yang, Thomas Chang-Yao Tsao, Kai-Bo Chang, et al. "Delivery Capacity and Anticancer Ability of the Berberine-Loaded Gold Nanoparticles to Promote the Apoptosis Effect in Breast Cancer." Cancers 13, no. 21 (October 22, 2021): 5317. http://dx.doi.org/10.3390/cancers13215317.

Full text

Abstract:

Gold nanoparticles (AuNPs) were fabricated with biocompatible collagen (Col) and then conjugated with berberine (BB), denoted as Au-Col-BB, to investigate the endocytic mechanisms in Her-2 breast cancer cell line and in bovine aortic endothelial cells (BAEC). Owing to the superior biocompatibility, tunable physicochemical properties, and potential functionalization with biomolecules, AuNPs have been well studied as carriers of biomolecules for diseases and cancer therapeutics. Composites of AuNPs with biopolymer, such as fibronectin or Col, have been revealed to increase cell proliferation, migration, and differentiation. BB is a natural compound with impressive health benefits, such as lowering blood sugar and reducing weight. In addition, BB can inhibit cell proliferation by modulating cell cycle progress and autophagy, and induce cell apoptosis in vivo and in vitro. In the current research, BB was conjugated on the Col-AuNP composite (“Au-Col”). The UV-Visible spectroscopy and infrared spectroscopy confirmed the conjugation of BB on Au-Col. The particle size of the Au-Col-BB conjugate was about 227 nm, determined by dynamic light scattering. Furthermore, Au-Col-BB was less cytotoxic to BAEC vs. Her-2 cell line in terms of MTT assay and cell cycle behavior. Au-Col-BB, compared to Au-Col, showed greater cell uptake capacity and potential cellular transportation by BAEC and Her-2 using the fluorescence-conjugated Au-Col-BB. In addition, the clathrin-mediated endocytosis and cell autophagy seemed to be the favorite endocytic mechanism for the internalization of Au-Col-BB by BAEC and Her-2. Au-Col-BB significantly inhibited cell migration in Her-2, but not in BAEC. Moreover, apoptotic cascade proteins, such as Bax and p21, were expressed in Her-2 after the treatment of Au-Col-BB. The tumor suppression was examined in a model of xenograft mice treated with Au-Col-BB nanovehicles. Results demonstrated that the tumor weight was remarkably reduced by the treatment of Au-Col-BB. Altogether, the promising findings of Au-Col-BB nanocarrier on Her-2 breast cancer cell line suggest that Au-Col-BB may be a good candidate of anticancer drug for the treatment of human breast cancer.

APA, Harvard, Vancouver, ISO, and other styles

27

Yoon, Jinho, Minkyu Shin, Taek Lee, and Jeong-Woo Choi. "Highly Sensitive Biosensors Based on Biomolecules and Functional Nanomaterials Depending on the Types of Nanomaterials: A Perspective Review." Materials 13, no. 2 (January 9, 2020): 299. http://dx.doi.org/10.3390/ma13020299.

Full text

Abstract:

Biosensors are very important for detecting target molecules with high accuracy, selectivity, and signal-to-noise ratio. Biosensors developed using biomolecules such as enzymes or nucleic acids which were used as the probes for detecting the target molecules were studied widely due to their advantages. For example, enzymes can react with certain molecules rapidly and selectively, and nucleic acids can bind to their complementary sequences delicately in nanoscale. In addition, biomolecules can be immobilized and conjugated with other materials by surface modification through the recombination or introduction of chemical linkers. However, these biosensors have some essential limitations because of instability and low signal strength derived from the detector biomolecules. Functional nanomaterials offer a solution to overcome these limitations of biomolecules by hybridization with or replacing the biomolecules. Functional nanomaterials can give advantages for developing biosensors including the increment of electrochemical signals, retention of activity of biomolecules for a long-term period, and extension of investigating tools by using its unique plasmonic and optical properties. Up to now, various nanomaterials were synthesized and reported, from widely used gold nanoparticles to novel nanomaterials that are either carbon-based or transition-metal dichalcogenide (TMD)-based. These nanomaterials were utilized either by themselves or by hybridization with other nanomaterials to develop highly sensitive biosensors. In this review, highly sensitive biosensors developed from excellent novel nanomaterials are discussed through a selective overview of recently reported researches. We also suggest creative breakthroughs for the development of next-generation biosensors using the novel nanomaterials for detecting harmful target molecules with high sensitivity.

APA, Harvard, Vancouver, ISO, and other styles

28

Evren, Gizem, Eray Er, Esra Evrim Yalcinkaya, Nesrin Horzum, and Dilek Odaci. "Electrospun Nanofibers including Organic/Inorganic Nanohybrids: Polystyrene- and Clay-Based Architectures in Immunosensor Preparation for Serum Amyloid A." Biosensors 13, no. 7 (June 23, 2023): 673. http://dx.doi.org/10.3390/bios13070673.

Full text

Abstract:

Diagnostic techniques based on biomolecules have application potential that can be realized in many fields, such as disease diagnosis, bioprocess imaging, food/beverage industries, and environmental pollutant imaging. Successful surface immobilization of biomolecules is critical to increasing the stabilization, sensitivity, and selectivity of biomolecules used in bioassay systems. Nanofibers are good candidates for the immobilization of biomolecules owing to many advantages such as morphology and pore size. In this study, montmorillonite (MMT) clay is modified with poly(amidoamine) (PAMAM) generation 3 (PAMAMG3) and added to polystyrene (PS) solutions, following which PS/MMT-PAMAMG3 nanofibers are obtained using the electrospinning method. The nanofibers are obtained by testing PS% (wt%) and MMT-PAMAMG3% (wt%) ratios and characterized with scanning electron microscopy. Antiserum amyloid A antibody (Anti-SAA) is then conjugated to the nanofibers on the electrode surface via covalent bonds using a zero-length cross linker. Finally, the obtained selective surface is used for electrochemical determination of serum amyloid A (SAA) levels. The linear range of PS/MMT-PAMAM/Anti-SAA is between 1 and 200 ng/mL SAA, and the detection limit is 0.57 ng/mL SAA. The applicability of PS/MMT-PAMAMG3/Anti-SAA is investigated by taking measurements in synthetic saliva and serum both containing SAA.

APA, Harvard, Vancouver, ISO, and other styles

29

Shumi, Gemechu, Tegene Desalegn, Taye B. Demissie, Venkatesha Perumal Ramachandran, and Rajalakshmanan Eswaramoorthy. "Metal Complexes in Target-Specific Anticancer Therapy: Recent Trends and Challenges." Journal of Chemistry 2022 (May 17, 2022): 1–19. http://dx.doi.org/10.1155/2022/9261683.

Full text

Abstract:

Cancer is characterized by abnormal cell differentiation in or on the part of the body. The most commonly used chemotherapeutic drugs are developed to target rapidly dividing cells, such as cancer cells, but they also damage healthy epithelial cells. This has serious consequences for normal cells and become responsible for the development of various disorders. Several strategies for delivering the cytotoxic drugs to cancerous sites that limit systemic toxicity and other adverse effects have recently been evolved. Among them, biomolecule-conjugated metal complexes-based cancer targeting strategies have shown tremendous advantages in cancer therapy. This review focuses on several chemoselective biomolecules-bound metal complexes as prospective cancer therapy-targeted agents. In this review, we presented the details of the various extra- and intracellular targeting mechanisms in cancer therapy. We also addressed the current clinical issues and recent therapeutic strategies in targeted cancer therapy that may pave a way for the future direction of metal complexes-based targeted cancer therapy.

APA, Harvard, Vancouver, ISO, and other styles

30

Angarita, Angie V., Adriana Umaña-Perez, and Leon D. Perez. "Enhancing the performance of PEG-b-PCL-based nanocarriers for curcumin through its conjugation with lipophilic biomolecules." Journal of Bioactive and Compatible Polymers 35, no. 4-5 (July 2020): 399–413. http://dx.doi.org/10.1177/0883911520944416.

Full text

Abstract:

Curcumin is a natural substance extracted from Curcuma longa Linn with beneficial pharmaceutical properties such as anticancer activity against several cellular lines. However, it presents poor bioavailability due to its low solubility in aqueous media and chemical instability. In this research, curcumin was encapsulated in polymer micelles obtained by the self-assembly of a biodegradable poly (ethylene glycol)-block-poly(ɛ-caprolactone) copolymer conjugated with cholesterol or oleic acid. A hydroxyl-terminated poly (ethylene glycol)-block-poly(ɛ-caprolactone) was reacted with cholesteryl chloroformate or oleyl chloride to obtain conjugated copolymers. The resulting polymeric materials were characterised through proton nuclear magnetic resonance, gel permeation chromatography and differential scanning calorimetry, and their critical aggregation concentration was measured through fluorescence spectroscopy. Poly (ethylene glycol)-block-poly(ɛ-caprolactone) conjugated with cholesterol and oleic acid posed an improved capacity of encapsulating curcumin, resulting in the loading capacities of 8.8% and 15.2%, respectively. Cell viability studies confirmed that curcumin loaded in polymer micelles maintained its anticancer activity against MCF-7 human breast cancer cells but presented low cytotoxicity against mouse fibroblasts. Hence, these formulations have good potential for applications in drug delivery systems for breast cancer treatment.

APA, Harvard, Vancouver, ISO, and other styles

31

Obaid, Girgis, Isabelle Chambrier, Michael J. Cook, and David A. Russell. "Cancer targeting with biomolecules: a comparative study of photodynamic therapy efficacy using antibody or lectin conjugated phthalocyanine-PEG gold nanoparticles." Photochemical & Photobiological Sciences 14, no. 4 (2015): 737–47. http://dx.doi.org/10.1039/c4pp00312h.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Augusto-Jimenez, Yarelys Elena, Marcela González-Montoya, Dany Naranjo-Feliciano, Daniel Uribe-Ramírez, Eliseo Cristiani-Urbina, Carlos Díaz-Águila, Hernani Yee-Madeira, and Rosalva Mora-Escobedo. "Antioxidant Activity of Bioactive Peptide Fractions from Germinated Soybeans Conjugated to Fe3O4 Nanoparticles by the Ugi Multicomponent Reaction." Molecules 26, no. 19 (September 22, 2021): 5726. http://dx.doi.org/10.3390/molecules26195726.

Full text

Abstract:

The conjugation of biomolecules to magnetic nanoparticles has emerged as promising approach in biomedicine as the treatment of several diseases, such as cancer. In this study, conjugation of bioactive peptide fractions from germinated soybeans to magnetite nanoparticles was achieved. Different fractions of germinated soybean peptides (>10 kDa and 5–10 kDa) were for the first time conjugated to previously coated magnetite nanoparticles (with 3-aminopropyltriethoxysilane (APTES) and sodium citrate) by the Ugi four-component reaction. The crystallinity of the nanoparticles was corroborated by X-ray diffraction, while the particle size was determined by scanning transmission electron microscopy. The analyses were carried out using infrared and ultraviolet–visible spectroscopy, dynamic light scattering, and thermogravimetry, which confirmed the coating and functionalization of the magnetite nanoparticles and conjugation of different peptide fractions on their surfaces. The antioxidant activity of the conjugates was determined by the reducing power and hydroxyl radical scavenging activity. The nanoparticles synthesized represent promising materials, as they have found applications in bionanotechnology for enhanced treatment of diseases, such as cancer, due to a higher antioxidant capacity than that of fractions without conjugation. The highest antioxidant capacity was observed for a >10 kDa peptide fraction conjugated to the magnetite nanoparticles coated with APTES.

APA, Harvard, Vancouver, ISO, and other styles

33

Kim, Dongmin, and Seungmin Yoo. "Aptamer-Conjugated Quantum Dot Optical Biosensors: Strategies and Applications." Chemosensors 9, no. 11 (November 12, 2021): 318. http://dx.doi.org/10.3390/chemosensors9110318.

Full text

Abstract:

Quantum dots (QDs) represent the promising new generation of luminophores owing to their size-, composition-, and surface-dependent tunable photoluminescence (PL) and photochemical stability. The development of various QD composites with high PL and good biocompatibility has facilitated the use of aptamer-functionalized QD biosensors for highly sensitive and specific detection of molecules in clinical and environmental settings. In addition to describing the recent advances in aptamer-based QD biosensor technology for the detection of diverse chemicals and biomolecules, this review provides recent examples of sensing strategies based on optical signal enhancement and quenching of QDs. It also discusses potential strategies for the development of biosensors to widen their practical applications across various scientific and technological fields.

APA, Harvard, Vancouver, ISO, and other styles

34

Barba-Vicente, Víctor, María Jesús Almendral Parra, Juan Francisco Boyero-Benito, Carlota Auría-Soro, Pablo Juanes-Velasco, Alicia Landeira-Viñuela, Álvaro Furones-Cuadrado, Ángela-Patricia Hernández, Raúl Manzano-Román, and Manuel Fuentes. "Detection of Human p53 In-Vitro Expressed in a Transcription-Translation Cell-Free System by a Novel Conjugate Based on Cadmium Sulphide Nanoparticles." Nanomaterials 10, no. 5 (May 21, 2020): 984. http://dx.doi.org/10.3390/nano10050984.

Full text

Abstract:

Here, cadmium sulphide quantum dots (CdS QDs) have been synthetized and functionalized with Bovine Serum Albumin (BSA) in a colloidal aqueous solution with a stability of over 3 months. Specific synthesis conditions, in homogeneous phase and at low temperature, have allowed limitation of S2− concentration, hence, as a consequence, there is restricted growth of the nanoparticles (NPs). This fact allows binding with BSA in the most favorable manner for the biomolecule. The presence of Cd2+ ions on the surface of the CdS nanoparticle is counteracted by the negatively charged domains of the BSA, resulting in the formation of small NPs, with little tendency for aggregation. Temperature and pH have great influence on the fluorescence characteristics of the synthetized nanoparticles. Working at low temperatures (4 °C) and pH 10–11 have proven the best result as shown by hydrolysis kinetic control of the thioacetamide precursor of S2− ion. Biological activity of the coupled BSA is maintained allowing subsequent bioconjugation with other biomolecules such as antibodies. The chemical conjugation with anti-Glutathione S-transferase (α-GST) antibody, a common tag employed in human recombinant fusion proteins, produces a strong quenching of fluorescence that proves the possibilities of its use in biological labelling. Finally, p53, onco-human recombinant protein (GST tagged in COOH terminus), has been in situ IVTT (in vitro transcription-translation) expressed and efficiently captured by the α-GST-CdS QD conjugate as a proof of the biocompatibility on IVTT systems and the functionality of conjugated antibody.

APA, Harvard, Vancouver, ISO, and other styles

35

Siti, Rabizah Makhsin, Abdul Razak Khairunisak, Abdul Aziz Azlan, and Rahmah Noordin. "Green Synthesis of 10 nm Gold Nanoparticles via Seeded-Growth Method and its Conjugation Properties on Lateral Flow Immunoassay." Advanced Materials Research 686 (April 2013): 8–12. http://dx.doi.org/10.4028/www.scientific.net/amr.686.8.

Full text

Abstract:

In this work, 10 nm gold nanoparticles (AuNPs) was successfully synthesized via seeded-growth method. The green chemically synthesis of this AuNPs becomes attractive because the growth process does not involve heat. Moreover, this technique has advantages of quick, simple, and low cost process. Sodium borohydrate (NaBH4) was used as a reducing agent while trisodium citrate was used as a source of OH- ions in the seed stage. Hydroxylamine hydrochloride (NH4.3H2O) was used as a slow reducing agent to enlarge 4 nm seeds to 10 nm AuNPs. A 4 ml AuNPs seed was the optimized volume to produce 10 nm AuNPs with great homogeneity and dispersity. A sharp peak of surface plasmon resonance (SPR) measurement at 517 nm proved that 10 nm AuNPs was successfully synthesized via this method. Optical properties of the seeds and grown AuNPs were analyzed using UV-Vis spectroscopy while size and surface morphology were observed using a transmission electron microscopy (TEM). Particle size distribution was measured using Zetasizer. 10 nm AuNPs was then conjugated with streptavidin and goat anti-human IgA. Depending on type of protein, 10 µg/ml of streptavidin and 11.2 µg/ml of goat anti-human IgA were required to conjugate with 10 nm AuNPs. The produced products had binding capability on lateral flow immunoassay (LFI). A few nanometer red-shifted absorption spectrum of 10 nm AuNPs conjugated protein revealed successful conjugation instead of agglomeration. 1% BSA was determined as the optimum concentration to stabilize 10 nm AuNPs conjugated biomolecules.

APA, Harvard, Vancouver, ISO, and other styles

36

Anniebell, Stanley, and Subash C. B. Gopinath. "Polymer Conjugated Gold Nanoparticles in Biomedical Applications." Current Medicinal Chemistry 25, no. 12 (April 19, 2018): 1433–45. http://dx.doi.org/10.2174/0929867324666170116123633.

Full text

Abstract:

Background: Research interest on the properties of polymer conjugated gold nanoparticle (GNP) in biomedicine is rapidly rising because of the extensive evidences for their unique properties. In the field of biomedicine, GNPs have been widely used because of their inertness and low levels of cytotoxicity. Therefore, when exposed to cells, they are less prone to exert damaging effects. GNPs are capable of being functionalized as desired and are ideal as they do not encourage undesired side reactions that might counter react with the intention of the functionalization. Biofouling is an occurrence that takes place at cellular and biological molecular level, binds non-specifically on the detection surface and forms a wrong output. This undesired incidence can be avoided by conjugating the surface of biomolecules with polymers. Densely packed repeating chains of polymers such as polyethylene glycol are capable of decreasing non-specific reactions. Applications of polymer conjugated GNPs in the field of biomedicine are as biosensors, delivery and therapeutic agents. Conclusion: Therefore, the properties and applications of polymer conjugated GNPs are studied widely as overviewed here.

APA, Harvard, Vancouver, ISO, and other styles

37

Pashazadeh-Panahi, Paria, Simin Belali, Hessamaddin Sohrabi, Fatemeh Oroojalian, Mahmoud Hashemzaei, Ahad Mokhtarzadeh, and Miguel de la Guardia. "Metal-organic frameworks conjugated with biomolecules as efficient platforms for development of biosensors." TrAC Trends in Analytical Chemistry 141 (August 2021): 116285. http://dx.doi.org/10.1016/j.trac.2021.116285.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Wang, Lihua, Shiping Song, Dun Pan, Di Li, and Chunhai Fan. "Gold nanoparticle-based sensing strategies for biomolecular detection." Pure and Applied Chemistry 82, no. 1 (January 12, 2010): 81–89. http://dx.doi.org/10.1351/pac-con-09-01-20.

Full text

Abstract:

Gold nanoparticles (AuNPs) have been extensively employed in biological studies for several decades. More recently, progress has well demonstrated that DNA-conjugated AuNPs are highly promising nanoprobes for the sensitive detection of various biomolecules, based on the unique optical and electronic properties of AuNPs. In this short review, we focus on the use of AuNP-based nanoprobes for biological detection of nucleic acids, proteins, and other biologically relevant small-molecule targets, mainly based on the recent progress in our laboratory.

APA, Harvard, Vancouver, ISO, and other styles

39

Ngo, An Thien, Pierre Karam, and Gonzalo Cosa. "Conjugated polyelectrolyte–lipid interactions: Opportunities in biosensing." Pure and Applied Chemistry 83, no. 1 (December 3, 2010): 43–55. http://dx.doi.org/10.1351/pac-con-10-11-02.

Full text

Abstract:

Fluorescent conjugated polyelectrolytes (CPEs) have attracted considerable interest over the past decade as novel materials for developing biosensing schemes and sensing devices for biomolecules. This interest stems from the exquisite polymer sensitivity to the presence of fluorescence quenchers, enabling amplified sensing of molecules of interest. Efficient energy transport along the polymer backbone is critical to their sensing capabilities. Considerable research efforts have thus gone into understanding and controlling energy transport along the polymer backbone. In particular, it has been shown that interactions between CPEs with either surfactants or lipid molecules may significantly reduce energy transport along the polymer backbone that in turn may provide for unique biosensing opportunities. In the first half of this review, we give a historical overview on energy transport in conjugated polymers and polyelectrolytes. In the second half, we summarize the most recent work on the interaction of CPEs with surfactants with an emphasis on our own work elucidating electronic energy transport in CPEs encapsulated into lipid vesicles or embedded within the membrane of lipid vesicles.

APA, Harvard, Vancouver, ISO, and other styles

40

Perera, Yasiru Randika, Joanna Xiuzhu Xu, Dhanush L. Amarasekara, Alex C. Hughes, Ibraheem Abbood, and Nicholas C. Fitzkee. "Understanding the Adsorption of Peptides and Proteins onto PEGylated Gold Nanoparticles." Molecules 26, no. 19 (September 24, 2021): 5788. http://dx.doi.org/10.3390/molecules26195788.

Full text

Abstract:

Polyethylene glycol (PEG) surface conjugations are widely employed to render passivating properties to nanoparticles in biological applications. The benefits of surface passivation by PEG are reduced protein adsorption, diminished non-specific interactions, and improvement in pharmacokinetics. However, the limitations of PEG passivation remain an active area of research, and recent examples from the literature demonstrate how PEG passivation can fail. Here, we study the adsorption amount of biomolecules to PEGylated gold nanoparticles (AuNPs), focusing on how different protein properties influence binding. The AuNPs are PEGylated with three different sizes of conjugated PEG chains, and we examine interactions with proteins of different sizes, charges, and surface cysteine content. The experiments are carried out in vitro at physiologically relevant timescales to obtain the adsorption amounts and rates of each biomolecule on AuNP-PEGs of varying compositions. Our findings are relevant in understanding how protein size and the surface cysteine content affect binding, and our work reveals that cysteine residues can dramatically increase adsorption rates on PEGylated AuNPs. Moreover, shorter chain PEG molecules passivate the AuNP surface more effectively against all protein types.

APA, Harvard, Vancouver, ISO, and other styles

41

Nawade, Ashwini, Imran Pancha, and Sabyasachi Mukhopadhyay. "Electron Transport across Phycobiliprotein Films and Its Optoelectronic Properties." ECS Journal of Solid State Science and Technology 11, no. 4 (April 1, 2022): 045004. http://dx.doi.org/10.1149/2162-8777/ac627f.

Full text

Abstract:

Biomolecules such as proteins, peptides being the most crucial life-forms, have an intimate relationship with various life activities for biological functions. Recent, contemporary work with biomolecules mainly focuses on its evolving potential associated with nanoscale electronics where proteins and peptides are integrated as sensing materials. We have explored the optoelectronics functionality of combined proteins known as phycobiliproteins. We have investigated electron transport behavior across the phycobiliproteins films under dark and white light illumination. We affirm that the photochemical activity of the protein is more stable in a solid-state/ thin film with tightly bonded water molecules than its presence in a buffer solution. Furthermore, our studies demonstrate that phycobiliproteins films modulate their electrical conductivity within their different conformation states. We speculate that the electrical conductance variation could originate from the chemical alteration of cysteine-conjugated bilin chromophores to protein and the electrostatic environment around the chromophores.

APA, Harvard, Vancouver, ISO, and other styles

42

Vos, Rita, Tim Steylaerts, Alexis Franquet, Alain Moussa, Tim Stakenborg, and Karolien Jans. "Vapor-Phase Deposition of N₃-Containing Monolayers on SiO₂ and Si₃N₄ for Wafer Scale Biofunctionalization." Solid State Phenomena 282 (August 2018): 31–36. http://dx.doi.org/10.4028/www.scientific.net/ssp.282.31.

Full text

Abstract:

The vapor-phase deposition of 11-azidoundecyltrimethoxysilanes at reduced pressure and elevated temperature allows the introduction of azido (N3) functionalized silicon wafer substrates. This process can be optimized by controlling the amount of surface adsorbed water and results in uniform and reproducible self-assembled monolayers (SAMs). The N3-SAM density as investigated via TOF-SIMS is comparable on thermal oxide and Si3N4substrates. Furthermore, it is demonstrated that biomolecules can be successfully conjugated on both substrates using azide-alkyne ‘click’ reactions.

APA, Harvard, Vancouver, ISO, and other styles

43

Wu, Zhengliang L., Anthony D. Person, Andrew J. Burton, Ravinder Singh, Barbara Burroughs, Dan Fryxell, Timothy J. Tatge, et al. "Direct fluorescent glycan labeling with recombinant sialyltransferases." Glycobiology 29, no. 11 (July 30, 2019): 750–54. http://dx.doi.org/10.1093/glycob/cwz058.

Full text

Abstract:

Abstract Glycosylation is a common modification found on numerous proteins and lipids. However, direct detection of glycans on these intact biomolecules has been challenge. Here, utilizing enzymatic incorporation of fluorophore-conjugated sialic acids, dubbed as direct fluorescent glycan labeling, we report the labeling and detection of N- and O-glycans on glycoproteins. The method allows detection of specific glycans without the laborious gel blotting and chemiluminescence reactions used in Western blotting. The method can also be used with a variety of fluorescent dyes.

APA, Harvard, Vancouver, ISO, and other styles

44

Arnusch, Christopher J., Hannah Ulm, Michaele Josten, Yana Shadkchan, Nir Osherov, Hans-Georg Sahl, and Yechiel Shai. "Ultrashort Peptide Bioconjugates Are Exclusively Antifungal Agents and Synergize with Cyclodextrin and Amphotericin B." Antimicrobial Agents and Chemotherapy 56, no. 1 (October 17, 2011): 1–9. http://dx.doi.org/10.1128/aac.00468-11.

Full text

Abstract:

ABSTRACTMany natural broad-spectrum cationic antimicrobial peptides (AMPs) possess a general mode of action that is dependent on lipophilicity and charge. Modulating the lipophilicity of AMPs by the addition of a fatty acid has been an effective strategy to increase the lytic activity and can further broaden the spectrum of AMPs. However, lipophilic modifications that narrow the spectrum of activity and exclusively direct peptides to fungi are less common. Here, we show that short peptide sequences can be targeted to fungi with structured lipophilic biomolecules, such as vitamin E and cholesterol. The conjugates were active againstAspergillus fumigatus,Cryptococcus neoformans, andCandida albicansbut not against bacteria and were observed to cause membrane perturbation by transmission electron microscopy and in membrane permeability studies. However, forC. albicans, selected compounds were effective without the perturbation of the cell membrane, and synergism was seen with a vitamin E conjugate and amphotericin B. Moreover, in combination with β-cyclodextrin, antibacterial activity emerged in selected compounds. Biocompatibility for selected active compounds was testedin vitroandin vivousing toxicity assays on erythrocytes, macrophages, and mice.In vitrocytotoxicity experiments led to selective toxicity ratios (50% lethal concentration/MIC) of up to 64 for highly active antifungal compounds, and noin vivomurine toxicity was seen. Taken together, these results highlight the importance of the conjugated lipophilic structure and suggest that the modulation of other biologically relevant peptides with hydrophobic moieties, such as cholesterol and vitamin E, generate compounds with unique bioactivity.

APA, Harvard, Vancouver, ISO, and other styles

45

Abes, R., A. A. Arzumanov, H. M. Moulton, S. Abes, G. D. Ivanova, P. L. Iversen, M. J. Gait, and B. Lebleu. "Cell-penetrating-peptide-based delivery of oligonucleotides: an overview." Biochemical Society Transactions 35, no. 4 (July 20, 2007): 775–79. http://dx.doi.org/10.1042/bst0350775.

Full text

Abstract:

Cationic CPPs (cell-penetrating peptides) have been used largely for intracellular delivery of low-molecular-mass drugs, biomolecules and particles. Most cationic CPPs bind to cell-associated glycosaminoglycans and are internalized by endocytosis, although the detailed mechanisms involved remain controversial. Sequestration and degradation in endocytic vesicles severely limits the efficiency of cytoplasmic and/or nuclear delivery of CPP-conjugated material. Re-routing the splicing machinery by using steric-block ON (oligonucleotide) analogues, such as PNAs (peptide nucleic acids) or PMOs (phosphorodiamidate morpholino oligomers), has consequently been inefficient when ONs are conjugated with standard CPPs such as Tat (transactivator of transcription), R9 (nona-arginine), K8 (octalysine) or penetratin in the absence of endosomolytic agents. New arginine-rich CPPs such as (R-Ahx-R)4 (6-aminohexanoic acid-spaced oligo-arginine) or R6 (hexa-arginine)–penetratin conjugated to PMO or PNA resulted in efficient splicing correction at non-cytotoxic doses in the absence of chloroquine. SAR (structure–activity relationship) analyses are underway to optimize these peptide delivery vectors and to understand their mechanisms of cellular internalization.

APA, Harvard, Vancouver, ISO, and other styles

46

Jiang, Nan, Jing Ma, and Yuansheng Jiang. "Electrostatic field-adapted molecular fractionation with conjugated caps for energy calculations of charged biomolecules." Journal of Chemical Physics 124, no. 11 (March 21, 2006): 114112. http://dx.doi.org/10.1063/1.2178796.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Kim, Young‐Pil, Hyun Kyong Shon, Seung Koo Shin, and Tae Geol Lee. "Probing nanoparticles and nanoparticle‐conjugated biomolecules using time‐of‐flight secondary ion mass spectrometry." Mass Spectrometry Reviews 34, no. 2 (June 2, 2014): 237–47. http://dx.doi.org/10.1002/mas.21437.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Goodge, Katarina, and Margaret Frey. "Biotin-Conjugated Cellulose Nanofibers Prepared via Copper-Catalyzed Alkyne-Azide Cycloaddition (CuAAC) “Click” Chemistry." Nanomaterials 10, no. 6 (June 16, 2020): 1172. http://dx.doi.org/10.3390/nano10061172.

Full text

Abstract:

As potential high surface area for selective capture in diagnostic or filtration devices, biotin-cellulose nanofiber membranes were fabricated to demonstrate the potential for specific and bio-orthogonal attachment of biomolecules onto nanofiber surfaces. Cellulose acetate was electrospun and substituted with alkyne groups in either a one- or two-step process. The alkyne reaction, confirmed by FTIR and Raman spectroscopy, was dependent on solvent ratio, time, and temperature. The two-step process maximized alkyne substitution in 10/90 volume per volume ratio (v/v) water to isopropanol at 50 °C after 6 h compared to the one-step process in 80/20 (v/v) at 50 °C after 48 h. Azide-biotin conjugate “clicked” with the alkyne-cellulose via copper-catalyzed alkyne-azide cycloaddition (CuAAC). The biotin-cellulose membranes, characterized by FTIR, SEM, Energy Dispersive X-ray spectroscopy (EDX), and XPS, were used in proof-of-concept assays (HABA (4′-hydroxyazobenzene-2-carboxylic acid) colorimetric assay and fluorescently tagged streptavidin assay) where streptavidin selectively bound to the pendant biotin. The click reaction was specific to alkyne-azide coupling and dependent on pH, ratio of ascorbic acid to copper sulfate, and time. Copper (II) reduction to copper (I) was successful without ascorbic acid, increasing the viability of the click conjugation with biomolecules. The surface-available biotin was dependent on storage medium and time: Decreasing with immersion in water and increasing with storage in air.

APA, Harvard, Vancouver, ISO, and other styles

49

Wang, Zi Ye, Kang Wang, and Xue Mei Ma. "Gold Magnetic Particle Based Immunoassay on a Disposable Microchips." Advanced Materials Research 236-238 (May 2011): 1931–34. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.1931.

Full text

Abstract:

Microchips appear to offer important opportunities for modern research. Microchips based on gold magnetic nanoparticles make manipulation of biomolecules more conveniently, and has the advantage of deducing reaction time. In this study, we first achieved microchips design and fabrication through CO2 laser ablation for immunoassay, and then conjugated mouse IgG to gold magnetic nanoparticles serve as a target. Finally, HRP labeled goat anti mouse IgG binding assay and substrate reaction were performed with disposable microchips and other devices. The results indicated that the reactions carried on successfully and magnetic particles moved well in chips.

APA, Harvard, Vancouver, ISO, and other styles

50

Singh, Abha, Siddhartha Samanta, Nirgaman Bage, Barnali Dasgupta Ghosh, Pradip Kar, and Poulomi Roy. "Synthesis of stable aqueous colloid of functionalized silver nanorod." Functional Materials Letters 12, no. 05 (September 17, 2019): 1950076. http://dx.doi.org/10.1142/s1793604719500760.

Full text

Abstract:

The aqueous colloid of mercapto ligand-functionalized silver nanorod was successfully synthesized by citric acid reduction method. The bigger silver nanospheres were preferably stabilizing in nanorod structure due to the presence of very high concentrations of both silver salts as well as mercapto ligand stabilizer. The properties and stability of the mercapto ligand-functionalized silver nanorod in aqueous colloid was investigated from standard characterizations. These types of surface functionalization silver nanorod conjugated with various biomolecules have been considered as interesting probe in electrochemical bioassay with improved sensitivity, selectivity for biomedical application and clinical analysis purpose.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Conjugated Biomolecules'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles