Impedimetric immunosensor using avidin–biotin for antibody immobilization

Ouerghi, Oussama; Touhami, Ahmed; Jaffrézic‐Renault, Nicole; Martelet, C.; Ouada, H. Ben; Cosnier, Serge

doi:10.1016/s1567-5394(02)00029-4

Cited by 103 publications

(44 citation statements)

References 6 publications

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“…A large variety of chemical coupling reactions was applied to covalently link antigen or antibody molecules to functional groups provided by selfassembled thiol monolayers [70]. Non-covalent affinity binding of antibodies to an electrode surface has been exemplified with a biotinylated antibody (anti-human IgG) bound to a biotinylated polypyrrole layer through avidin linker [71], Scheme 6D. Direct visualization of IgG binding on different surfaces was achieved using AFM, and the results were compared with impedance spectra changes [72].…”

Section: Immunosensors Based On Interfacial Impedance Measurements Atmentioning

confidence: 99%

Probing Biomolecular Interactions at Conductive and Semiconductive Surfaces by Impedance Spectroscopy: Routes to Impedimetric Immunosensors, DNA‐Sensors, and Enzyme Biosensors

2003

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Impedance spectroscopy is a rapidly developing electrochemical technique for the characterization of biomaterialfunctionalized electrodes and biocatalytic transformations at electrode surfaces, and specifically for the transduction of biosensing events at electrodes or field-effect transistor devices. The immobilization of biomaterials, e.g., enzymes, antigens/antibodies or DNA on electrodes or semiconductor surfaces alters the capacitance and interfacial electron transfer resistance of the conductive or semiconductive electrodes. Impedance spectroscopy allows analysis of interfacial changes originating from biorecognition events at electrode surfaces. Kinetics and mechanisms of electron transfer processes corresponding to biocatalytic reactions occurring at modified electrodes can be also derived from Faradaic impedance spectroscopy. Different immunosensors that use impedance measurements for the transduction of antigen-antibody complex formation on electronic transducers were developed. Similarly, DNA biosensors using impedance measurements as readout signals were developed. Amplified detection of the analyte DNA using Faradaic impedance spectroscopy was accomplished by the coupling of functionalized liposomes or by the association of biocatalytic conjugates to the sensing interface providing biocatalyzed precipitation of an insoluble product on the electrodes. The amplified detections of viral DNA and single-base mismatches in DNA were accomplished by similar methods. The changes of interfacial features of gate surfaces of field-effect transistors (FET) upon the formation of antigen-antibody complexes or assembly of protein arrays were probed by impedance measurements and specifically by transconductance measurements. Impedance spectroscopy was also applied to characterize enzymebased biosensors. The reconstitution of apo-enzymes on cofactor-functionalized electrodes and the formation of cofactor-enzyme affinity complexes on electrodes were probed by Faradaic impedance spectroscopy. Also biocatalyzed reactions occurring on electrode surfaces were analyzed by impedance spectroscopy. The theoretical background of the different methods and their practical applications in analytical procedures were outlined in this article.

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Section: Immunosensors Based On Interfacial Impedance Measurements Atmentioning

confidence: 99%

Probing Biomolecular Interactions at Conductive and Semiconductive Surfaces by Impedance Spectroscopy: Routes to Impedimetric Immunosensors, DNA‐Sensors, and Enzyme Biosensors

2003

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“…Methods for immobilizing proteins on gold film, which have been investigated for years, include the SPA method (15,23 ), the avidin and biotin method (24,25 ), and the self-assembled monolayers method (26,27 ). The SPA method was adopted in the present experiment because it can create more reproducible and stable immobilization layers with less added mass for IgG coating (28 ).…”

Section: Results and Discussion Optimization Of Immobilized Antibody mentioning

confidence: 99%

Rapid and Simultaneous Quantification of 4 Urinary Proteins by Piezoelectric Quartz Crystal Microbalance Immunosensor Array

Luo¹,

Chen²,

Qin

et al. 2006

Clinical Chemistry

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Background: Urinary proteins are predictive and prognostic markers for diabetes nephropathy. Conventional methods for the quantification of urinary proteins, however, are time-consuming, and most require radioactive labeling. We designed a label-free piezoelectric quartz crystal microbalance (QCM) immunosensor array to simultaneously quantify 4 urinary proteins. Methods: We constructed a 2 ؋ 5 model piezoelectric immunosensor array fabricated with disposable quartz crystals for quantification of microalbumin, ␣ 1 -microglobulin, ␤ 2 -microglobulin, and IgG in urine. We made calibration curves after immobilization of antibodies at an optimal concentration and then evaluated the performance characteristics of the immunosensor with a series of tests. In addition, we measured 124 urine samples with both QCM immunosensor array and immunonephelometry to assess the correlation between the 2 methods. Results: With the QCM immunosensor array, we were able to quantify 4 urinary proteins within 15 min. This method had an analytical interval of 0.01-60 mg/L. The intraassay and interassay imprecisions (CVs) were <10%, and the relative recovery rates were 90.3%-109.1%. Nonspecificity of the immunosensor was insignificant (frequency shifts <20 Hz). ROC analyses indicated sensitivities were >95.8% and, specificities were

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“…This can result in an improved immunosensor response as the conductivity of the polymer film is strongly affected by conformal changes induced during the binding event [76,77]. Biotinylated polypyrrol films have been used to immobilize biotinylated antibodies via avidin [78]. The antigen binding results in an increase in the Rct with a LOD of 10 pg ml −1 observed for human IgG.…”

Section: Faradaic Impedance Immunosensorsmentioning

confidence: 99%