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Sakata T, Shiratori R, Nishitani S. Aptamer-Based Glycated Albumin Sensor for Capacitive Spectroscopy. Anal Chem 2023; 95:1480-1489. [PMID: 36583969 DOI: 10.1021/acs.analchem.2c04505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Glycated albumin (GA) is a candidate for glycemic indicator to control prediabetes, the half-life of which is about 2 weeks, which is neither too long nor too short, considering that there is no longer any need for daily fingerstick sampling but glucose levels can be controlled in a relatively short term. Its usefulness as a glycemic indicator must be widely recognized by developing a simple and miniaturized GA sensor for point-of-care testing (POCT) devices. In this study, we propose an aptamer-based capacitive electrode for electrochemical capacitance spectroscopy (ECS) to specifically detect GA in an enzyme-/antibody-free manner. As a component of the bioelectrical interface between the sample solution and the electrode, a densely packed capacitive polyaryl film coated on a gold electrode contributes to the detection of GA by the ECS method. In addition, the GA aptamer tethered onto the polyaryl-film-coated gold electrode is useful for not only specifically capturing GA but also inducing changes in the concentration of cations released from the cation/GA aptamer complexes by GA/GA aptamer binding. Also, hydrophilic poly(ethylene glycol) (PEG) coated on the polyaryl film electrode in parallel with the GA aptamer prevents interfering proteins such as human serum albumin (HSA) and immunoglobulin G (IgG) from nonspecifically absorbing on the polyaryl film electrode. Such a GA aptamer-based capacitive electrode produces significant signals of GA against HSA and IgG with the change in GA concentration (0.1, 1, and 10 mg/mL) detected by the ECS method. This indicates that the ECS method contributes to the evaluation of the GA level, which is based on the rate of glycation of albumin. Thus, a platform based on ECS measurement using the aptamer-based capacitive electrode is useful for protein analysis in an enzyme-/antibody-free manner.
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Affiliation(s)
- Toshiya Sakata
- Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Reiko Shiratori
- Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Shoichi Nishitani
- Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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2
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Nishitani S, Fukuma T, Himori S, Man Y, Shiratori R, Sakata T. Densification of Diazonium-Based Organic Thin Film as Bioelectrical Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:14369-14379. [PMID: 34854684 DOI: 10.1021/acs.langmuir.1c02291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Aryl diazonium chemistry generates a covalently attached thin film on various materials. This chemistry has diverse applications owing to the stability, ease of functionalization, and versatility of the film. However, the uncontrolled growth into a polyaryl film has limited the controllability of the film's beneficial properties. In this study, we developed a multistep grafting protocol to densify the film while maintaining a thickness on the order of nanometers. This simple protocol enabled the full passivation of a nitrophenyl polyaryl film, completely eliminating the electrochemical reactions at the surface. We then applied this protocol to the grafting of phenylphosphorylcholine films, with which the densification significantly enhanced the antifouling property of the film. Together with its potential to precisely control the density of functionalized surfaces, we believe this grafting procedure will have applications in the development of bioelectrical interfaces.
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Affiliation(s)
- Shoichi Nishitani
- Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Toru Fukuma
- Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Shogo Himori
- Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Youyuan Man
- Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Reiko Shiratori
- Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Toshiya Sakata
- Department of Materials Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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3
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Legge EJ, Ali MM, Abbasi HY, Reed BP, Brennan B, Matjačić L, Tehrani Z, Stolojan V, Silva SRP, Guy OJ, Pollard AJ. Understanding the bonding mechanisms of organic molecules deposited on graphene for biosensing applications. J Chem Phys 2021; 155:174703. [PMID: 34742208 DOI: 10.1063/5.0064136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Graphene is an ideal material for biosensors due to the large surface area for multiple bonding sites, the high electrical conductivity allowing for high sensitivity, and the high tensile strength providing durability in fabricated sensor devices. For graphene to be successful as a biosensing platform, selectivity must be achieved through functionalization with specific chemical groups. However, the device performance and sensor sensitivity must still be maintained after functionalization, which can be challenging. We compare phenyl amine and 1,5-diaminonaphthalene functionalization methods for chemical vapor deposition grown graphene, both used to obtain graphene modified with amine groups-which is required for surface attachment of highly selective antibody bio-receptors. Through atomic force microscopy (AFM), Raman spectroscopy, and time-of-flight secondary ion mass spectrometry imaging of co-located areas, the chemistry, thickness, and coverage of the functional groups bound to the graphene surface have been comprehensively analyzed. We demonstrate the modification of functionalized graphene using AFM, which unexpectedly suggests the removal of covalently bonded functional groups, resulting in a "recovered" graphene structure with reduced disorder, confirmed with Raman spectroscopy. This removal explains the decrease in the ID/IG ratio observed in Raman spectra from other studies on functionalized graphene after mechanical strain or a chemical reaction and reveals the possibility of reverting to the non-functionalized graphene structure. Through this study, preferred functionalization processes are recommended to maintain the performance properties of graphene as a biosensor.
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Affiliation(s)
| | - Muhammad M Ali
- Centre of NanoHealth, College of Engineering, Swansea University, Swansea SA2 8PP, United Kingdom
| | - Hina Y Abbasi
- Centre of NanoHealth, College of Engineering, Swansea University, Swansea SA2 8PP, United Kingdom
| | - Benjamen P Reed
- National Physical Laboratory, Teddington TW11 0LW, United Kingdom
| | - Barry Brennan
- National Physical Laboratory, Teddington TW11 0LW, United Kingdom
| | - Lidija Matjačić
- National Physical Laboratory, Teddington TW11 0LW, United Kingdom
| | - Zari Tehrani
- Centre of NanoHealth, College of Engineering, Swansea University, Swansea SA2 8PP, United Kingdom
| | - Vlad Stolojan
- Advanced Technology Institute, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - S Ravi P Silva
- Advanced Technology Institute, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - Owen J Guy
- Centre of NanoHealth, College of Engineering, Swansea University, Swansea SA2 8PP, United Kingdom
| | - Andrew J Pollard
- National Physical Laboratory, Teddington TW11 0LW, United Kingdom
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4
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The numerical probability of carcinogenicity to humans of some antimicrobials: Nitro-monoaromatics (including 5-nitrofurans and 5-nitroimidazoles), quinoxaline-1,4-dioxides (including carbadox), and chloramphenicol. Toxicol In Vitro 2021; 75:105172. [PMID: 33862175 DOI: 10.1016/j.tiv.2021.105172] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/11/2021] [Accepted: 04/08/2021] [Indexed: 12/14/2022]
Abstract
Many substances are already tested in the long-term rodent bioassay (RCB). Nonetheless, statements such as the following are common in the regulatory literature: "the significance of the carcinogenicity findings in rodents relative to the therapeutic use of drugs in humans is unknown." (U.S. FDA prescribing information for nitrofurantoin). In the absence of epidemiological data, chemicals carcinogenic in RCBs are typically classified as either possibly or probably carcinogenic to humans, particularly without the -numerical probability for the carcinogenicity to humans- (PPV) of the classified substance. Through the biostatistics-based and regulatorily pertinent -predictive values approach- (PVA), the present study investigated the PPV of several antimicrobials relevant to human or veterinary medicine. A combination of structure-activity relationship, mutagenicity, and tumor-related histopathology was used to resolve reliable and pertinent PPVs. For 62 specific antimicrobials (e.g., carbadox), a 97.9% (or more) probability of carcinogenicity to humans was estimated. For nitrofurantoin, a 99.9% probability of carcinogenicity to humans was reckoned. Therefore, a risk-benefit evaluation on the in-force authorization of nitrofurantoin for uncomplicated human urinary infections is needed. A discussion was provided on the involved mechanisms of carcinogenic action and some regulatory implications of the findings. Neither this study nor the PVA aimed to encourage indiscriminate animal testing but the contrary, to reduce unnecessary or redundant in vivo testing by powering the predictivity of nonclinical toxicology.
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Assessing Surface Coverage of Aminophenyl Bonding Sites on Diazotised Glassy Carbon Electrodes for Optimised Electrochemical Biosensor Performance. NANOMATERIALS 2021; 11:nano11020416. [PMID: 33562051 PMCID: PMC7915090 DOI: 10.3390/nano11020416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 01/31/2021] [Accepted: 02/02/2021] [Indexed: 01/09/2023]
Abstract
Electrochemical biosensors using carbon-based electrodes are being widely developed for the detection of a range of different diseases. Since their sensitivity depends on the surface coverage of bioreceptor moieties, it necessarily depends on the surface coverage of amine precursors. Electrochemical techniques, using ferrocene carboxylic acid as a rapid and cheap assay, were used to assess the surface coverage of amino-phenyl groups attached to the carbon electrode. While the number of electrons transferred in the first step of diazotisation indicated a surface coverage of 8.02 ± 0.2 × l0−10 (mol/cm2), and those transferred in the second step, a reduction of nitrophenyl to amino-phenyl, indicated an amine surface coverage of 4–5 × l0−10 (mol/cm2), the number of electrons transferred during attachment of the amine coupling assay compound, ferrocene carboxylic acid, indicated a much lower available amine coverage of only 2.2 × l0−11 (mol/cm2). Furthermore, the available amine coverage was critically dependent upon the number of cyclic voltammetry cycles used in the reduction, and thus the procedures used in this step influenced the sensitivity of any subsequent sensor. Amine coupling of a carboxyl terminated anti-beta amyloid antibody specific to Aβ(1-42) peptide, a potential marker for Alzheimer’s disease, followed the same pattern of coverage as that observed with ferrocene carboxylic acid, and at optimum amine coverage, the sensitivity of the differential pulse voltammetry sensor was in the range 0–200 ng/mL with the slope of 5.07 µA/ng·mL−1 and R2 = 0.98.
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6
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Electrochemical immunoassay for the detection of stress biomarkers. Heliyon 2020; 6:e03558. [PMID: 32211542 PMCID: PMC7082534 DOI: 10.1016/j.heliyon.2020.e03558] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 01/09/2020] [Accepted: 03/04/2020] [Indexed: 01/11/2023] Open
Abstract
A rapid electrochemical immunoassay method was developed to detect and measure stress biomarkers (cortisol and cortisone) in two biological samples (Zebrafish whole-body and artificial saliva). This methodology utilizes an immunoassay approach taking advantage of the lock and key mechanism that is related to the antibody-antigen interaction depending on the reliable immobilization of the antibody labelled with ferrocene tags (Ab-Fc) on a modified tin-doped indium oxide (ITO) electrode using electrochemical instrumentation to build a POC platform. The limit of detection (LOD) obtained for this biosensor was 1.03 pg ml−1 for cortisol and 0.68 pg ml−1 for cortisone, respectively. The correlation coefficient was 0.9852 and 0.9841 for cortisol and cortisone, respectively with a linear concentration from (0-50 ng ml−1) which covers the standard levels of stress hormones in both selected biological samples. The incubation time was investigated and 30 min was found to be the optimum incubation time. This time would be acceptable for the POC system as total process time can be determined within 35 min.
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Harris TGAA, Heidary N, Kozuch J, Frielingsdorf S, Lenz O, Mroginski MA, Hildebrandt P, Zebger I, Fischer A. In Situ Spectroelectrochemical Studies into the Formation and Stability of Robust Diazonium-Derived Interfaces on Gold Electrodes for the Immobilization of an Oxygen-Tolerant Hydrogenase. ACS APPLIED MATERIALS & INTERFACES 2018; 10:23380-23391. [PMID: 29943966 DOI: 10.1021/acsami.8b02273] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Surface-enhanced infrared absorption spectroscopy is used in situ to determine the electrochemical stability of organic interfaces deposited onto the surface of nanostructured, thin-film gold electrodes via the electrochemical reduction of diazonium salts. These interfaces are shown to exhibit a wide electrochemical stability window in both acetonitrile and phosphate buffer, far surpassing the stability window of thiol-derived self-assembled monolayers. Using the same in situ technique, the application of radical scavengers during the electrochemical reduction of diazonium salts is shown to moderate interface formation. Consequently, the heterogeneous charge-transfer resistance can be reduced sufficiently to enhance the direct electron transfer between an immobilized redox-active enzyme and the electrode. This was demonstrated for the oxygen-tolerant [NiFe] hydrogenase from the "Knallgas" bacterium Ralstonia eutropha by relating its electrochemical activity for hydrogen oxidation to the interface properties.
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Affiliation(s)
- Tomos G A A Harris
- Institut für Chemie , Technische Universität Berlin , PC 14, Str. des 17. Juni 135 , 10623 Berlin , Germany
- Institut für Anorganische und Analytische Chemie , Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany
| | - Nina Heidary
- Institut für Chemie , Technische Universität Berlin , PC 14, Str. des 17. Juni 135 , 10623 Berlin , Germany
- Institut für Anorganische und Analytische Chemie , Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany
| | - Jacek Kozuch
- Institut für Chemie , Technische Universität Berlin , PC 14, Str. des 17. Juni 135 , 10623 Berlin , Germany
| | - Stefan Frielingsdorf
- Institut für Chemie , Technische Universität Berlin , PC 14, Str. des 17. Juni 135 , 10623 Berlin , Germany
| | - Oliver Lenz
- Institut für Chemie , Technische Universität Berlin , PC 14, Str. des 17. Juni 135 , 10623 Berlin , Germany
- FMF - Freiburger Materialforschungszentrum , Universität Freiburg , Stefan-Meier-Straße 21 , 79104 Freiburg , Germany
- FIT - Freiburger Zentrum für interaktive Werkstoffe und bioinspirierte Technologien , Georges-Köhler-Allee 105 , 79110 Freiburg , Germany
| | - Maria-Andrea Mroginski
- Institut für Chemie , Technische Universität Berlin , PC 14, Str. des 17. Juni 135 , 10623 Berlin , Germany
| | - Peter Hildebrandt
- Institut für Chemie , Technische Universität Berlin , PC 14, Str. des 17. Juni 135 , 10623 Berlin , Germany
| | - Ingo Zebger
- Institut für Chemie , Technische Universität Berlin , PC 14, Str. des 17. Juni 135 , 10623 Berlin , Germany
| | - Anna Fischer
- Institut für Anorganische und Analytische Chemie , Universität Freiburg , Albertstr. 21 , 79104 Freiburg , Germany
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8
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Adkins JA, Boehle K, Friend C, Chamberlain B, Bisha B, Henry CS. Colorimetric and Electrochemical Bacteria Detection Using Printed Paper- and Transparency-Based Analytic Devices. Anal Chem 2017; 89:3613-3621. [DOI: 10.1021/acs.analchem.6b05009] [Citation(s) in RCA: 145] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
| | | | | | | | - Bledar Bisha
- Department
of Animal Science, University of Wyoming, Laramie, Wyoming 82071, United States
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9
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Aryldiazonium salt derived mixed organic layers: From surface chemistry to their applications. J Electroanal Chem (Lausanne) 2017. [DOI: 10.1016/j.jelechem.2016.11.043] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Gearba RI, Mueller KM, Veneman PA, Holliday BJ, Chan CK, Stevenson KJ. Atom-scale covalent electrochemical modification of single-layer graphene on SiC substrates by diaryliodonium salts. J Electroanal Chem (Lausanne) 2015. [DOI: 10.1016/j.jelechem.2015.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Song Y, Chen C, Wang C. Graphene/enzyme-encrusted three-dimensional carbon micropillar arrays for mediatorless micro-biofuel cells. NANOSCALE 2015; 7:7084-7090. [PMID: 25619639 DOI: 10.1039/c4nr06856d] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Two-dimensional graphene is a promising candidate material for use in high-performance enzymatic biofuel cells (EBFCs). In this work, graphene/enzyme has been integrated onto three-dimensional (3D) micropillar arrays in order to obtain efficient enzyme immobilisation and enhanced enzyme loading and facilitate direct electron transfer. The fabrication process of this system combines top-down carbon microelectromechanical systems (C-MEMS) to fabricate the 3D micropillar array platform and bottom-up electrophoretic deposition (EPD) to deposit the graphene/enzyme onto the electrode surface. The amperometric response of the graphene-based bioelectrode exhibited excellent electrochemical activity, which indicated the successful co-deposition of graphene with the enzymes. The developed 3D graphene/enzyme network-based EBFC generated a maximum power density of 136.3 μW cm(-2) at 0.59 V, which is almost seven times the maximum power density of the bare 3D carbon micropillar array-based EBFC.
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Affiliation(s)
- Yin Song
- Department of Mechanical and Materials Engineering, Florida International University, 10555 W. Flagler St., Miami, FL 33174, USA.
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12
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Jiang C, Tanzirul Alam M, Parker SG, Gooding JJ. Zwitterionic Phenyl Phosphorylcholine on Indium Tin Oxide: a Low-Impedance Protein-Resistant Platform for Biosensing. ELECTROANAL 2015. [DOI: 10.1002/elan.201400557] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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13
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Menanteau T, Levillain E, Breton T. Spontaneous grafting of nitrophenyl groups on carbon: effect of radical scavenger on organic layer formation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:7913-7918. [PMID: 24932574 DOI: 10.1021/la501437g] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The effect of a radical scavenger (DPPH: 2,2-diphenyl-1-picrylhydrazyl) on the spontaneous covalent grafting of nitrophenyl functionalities on a vitreous carbon substrate using the 4-nitrobenzene diazonium cation has been studied by electrochemical measurements and X-ray photoelectron spectroscopy. The addition of micromolar concentrations of DPPH to the diazonium solution efficiently limits the multilayer formation and leads to monolayer surface coverage. Control of polyaryl layer formation via the capture of the reactive nitrophenyl radical was also found to increase the proportion of nitrophenyl groups grafted to the surface via azo bridges. This work validates the recently reported strategy using a radical scavenger to prevent the formation of a polyaryl layer without interfering with direct surface grafting.
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Affiliation(s)
- Thibaud Menanteau
- MOLTECH-Anjou, Université d'Angers - UMR CNRS 6200 , 2 Boulevard Lavoisier, 49045 Angers, France
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14
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15
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Parviz M, Darwish N, Alam MT, Parker SG, Ciampi S, Gooding JJ. Investigation of the Antifouling Properties of Phenyl Phosphorylcholine-Based Modified Gold Surfaces. ELECTROANAL 2014. [DOI: 10.1002/elan.201400102] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Liu G, Guo W, Song D. A multianalyte electrochemical immunosensor based on patterned carbon nanotubes modified substrates for detection of pesticides. Biosens Bioelectron 2014; 52:360-6. [DOI: 10.1016/j.bios.2013.09.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 09/05/2013] [Accepted: 09/05/2013] [Indexed: 01/29/2023]
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17
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An Immunosensor for Pathogenic Staphylococcus aureus Based on Antibody Modified Aminophenyl-Au Electrode. ACTA ACUST UNITED AC 2013. [DOI: 10.1155/2013/367872] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The objective of this work is to elaborate an immunosensing system which will detect and quantify Staphylococcus aureus bacteria. A gold electrode was modified by electrografting of 4-nitrophenyl diazonium, in situ synthesized in acidic aqueous solution. The immunosensor was fabricated by immobilizing affinity-purified polyclonal anti S. aureus antibodies on the modified gold electrode. Cyclic voltammetry (CV) and Faradaic Electrochemical Impedance Spectroscopy (EIS) were employed to characterize the stepwise assembly of the immunosensor. The performance of the developed immunosensor was evaluated by monitoring the electron-transfer resistance detected using Faradaic EIS. The experimental results indicated a linear relationship between the relative variation of the electron transfer resistance and the logarithmic value of S. aureus concentration, with a slope of 0.40 ± 0.08 per decade of concentration. A low quantification limit of 10±2 CFU per ml and a linear range up to 107±2×106 CFU per mL were obtained. The developed immunosensors showed high selectivity to Escherichia coli and Staphylococcus saprophyticus.
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18
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Fairman C, Ginges JZ, Lowe SB, Gooding JJ. Protein Resistance of Surfaces Modified with Oligo(Ethylene Glycol) Aryl Diazonium Derivatives. Chemphyschem 2013; 14:2183-9. [DOI: 10.1002/cphc.201300040] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Indexed: 11/06/2022]
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19
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Kibena E, Marandi M, Mäeorg U, Venarusso LB, Maia G, Matisen L, Kasikov A, Sammelselg V, Tammeveski K. Electrochemical modification of gold electrodes with azobenzene derivatives by diazonium reduction. Chemphyschem 2013; 14:1043-54. [PMID: 23420610 DOI: 10.1002/cphc.201200934] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Indexed: 11/10/2022]
Abstract
An electrochemical study of Au electrodes electrografted with azobenzene (AB), Fast Garnet GBC (GBC) and Fast Black K (FBK) diazonium compounds is presented. Electrochemical quartz crystal microbalance, ellipsometry and atomic force microscopy investigations reveal the formation of multilayer films. The elemental composition of the aryl layers is examined by X-ray photoelectron spectroscopy. The electrochemical measurements reveal a quasi-reversible voltammogram of the Fe(CN)6 (3-/4-) redox couple on bare Au and a sigmoidal shape for the GBC- and FBK-modified Au electrodes, thus demonstrating that electron transfer is blocked due to the surface modification. The electrografted AB layer results in strongest inhibition of the Fe(CN)6 (3-/4-) response compared with other aryl layers. The same tendencies are observed for oxygen reduction; however, the blocking effect is not as strong as in the Fe(CN)6 (3-/4-) redox system. The electrochemical impedance spectroscopy measurements allowed the calculation of low charge-transfer rates to the Fe(CN)6 (3-) probe for the GBC- and FBK-modified Au electrodes in relation to bare Au. From these measurements it can be concluded that the FBK film is less compact or presents more pinholes than the electrografted GBC layer.
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Affiliation(s)
- Elo Kibena
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia
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Electrochemical immunosensor for the milk allergen β-lactoglobulin based on electrografting of organic film on graphene modified screen-printed carbon electrodes. Biosens Bioelectron 2012; 38:308-13. [DOI: 10.1016/j.bios.2012.06.008] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 06/05/2012] [Accepted: 06/06/2012] [Indexed: 11/17/2022]
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21
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Richard W, Evrard D, Gros P. New insight into 4-nitrobenzene diazonium reduction process: Evidence for a grafting step distinct from NO2 electrochemical reactivity. J Electroanal Chem (Lausanne) 2012. [DOI: 10.1016/j.jelechem.2012.09.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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González-Fuentes MA, Díaz-Sánchez BR, Vela A, González FJ. Radical grafting of carbon surfaces by oxidation of 5-nitroindole derived anions. J Electroanal Chem (Lausanne) 2012. [DOI: 10.1016/j.jelechem.2012.02.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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23
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Pilan L, Raicopol M, Pruna A, Branzoi V. Polyaniline/carbon nanotube composite films electrosynthesis through diazonium salts electroreduction and electrochemical polymerization. SURF INTERFACE ANAL 2012. [DOI: 10.1002/sia.4920] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Luisa Pilan
- University Politehnica of Bucharest; Faculty of Applied Chemistry and Materials Science; 1 Polizu 010737 Bucharest Romania
| | - Matei Raicopol
- University Politehnica of Bucharest; Faculty of Applied Chemistry and Materials Science; 1 Polizu 010737 Bucharest Romania
| | - Alina Pruna
- University Politehnica of Bucharest; Faculty of Applied Chemistry and Materials Science; 1 Polizu 010737 Bucharest Romania
| | - Viorel Branzoi
- University Politehnica of Bucharest; Faculty of Applied Chemistry and Materials Science; 1 Polizu 010737 Bucharest Romania
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24
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Raicopol M, Necula L, Ionita M, Pilan L. Electrochemical reduction of aryl diazonium salts: a versatile way for carbon nanotubes functionalisation. SURF INTERFACE ANAL 2012. [DOI: 10.1002/sia.4830] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Matei Raicopol
- Faculty of Applied Chemistry and Materials Science; University Politehnica of Bucharest; 1 Polizu; 010737; Bucharest; Romania
| | - Luiza Necula
- Faculty of Applied Chemistry and Materials Science; University Politehnica of Bucharest; 1 Polizu; 010737; Bucharest; Romania
| | - Mariana Ionita
- Faculty of Applied Chemistry and Materials Science; University Politehnica of Bucharest; 1 Polizu; 010737; Bucharest; Romania
| | - Luisa Pilan
- Faculty of Applied Chemistry and Materials Science; University Politehnica of Bucharest; 1 Polizu; 010737; Bucharest; Romania
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Voltammetry at graphite electrodes: The oxidation of hexacyanoferrate (II) (ferrocyanide) does not exhibit pure outer-sphere electron transfer kinetics and is sensitive to pre-exposure of the electrode to organic solvents. J Electroanal Chem (Lausanne) 2011. [DOI: 10.1016/j.jelechem.2011.07.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Blocking properties of gold electrodes modified with 4-nitrophenyl and 4-decylphenyl groups. J Solid State Electrochem 2011. [DOI: 10.1007/s10008-011-1381-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Moscoso R, Carbajo J, Lopez M, Núñez-Vergara L, Squella J. A simple derivatization of multiwalled carbon nanotubes with nitroaromatics in aqueous media: Modification with nitroso/hydroxylamine groups. Electrochem commun 2011. [DOI: 10.1016/j.elecom.2010.12.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Li Q, Batchelor-McAuley C, Lawrence NS, Hartshorne RS, Compton RG. The synthesis and characterisation of controlled thin sub-monolayer films of 2-anthraquinonyl groups on graphite surfaces. NEW J CHEM 2011. [DOI: 10.1039/c1nj20461k] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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