Amperometric Immunosensors Based on Protein A Coupled Polyaniline−Perfluorosulfonated Ionomer Composite Electrodes

• Published in: Analytical chemistry (Washington) Vol. 72; no. 13; pp. 2925 - 2929
• Main Authors: Liu, Chih-Hung, Liao, Kuo-Tang, Huang, Hsuan-Jung
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.07.2000
• Subjects: Aniline Compounds - chemistry; Biological and medical sciences; Biosensing Techniques; Biosensors; Biotechnology; Chemistry; Electrodes; Enzymes; Fluorocarbon Polymers - chemistry; Fundamental and applied biological sciences. Psychology; Indicators and Reagents; Methods. Procedures. Technologies; Proteins; Staphylococcal Protein A - chemistry; Various methods and equipments; Immunoglobulins; Enzyme; IgG; Rabbit; Urease; Protein A; Lagomorpha; Immunosensor; Composite material; Immunological method; Electrodes; Vertebrata; Mammalia; Biosensor; Amperometry; Hydrolases; Quantitative analysis; Aniline polymer
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac9914317

A very sensitive immunosensor based on polyaniline/Nafion/protein A (PA/NF/PrA) composite electrodes has been developed for the amperometric immunoanalysis with urease-labeled immunoreagents. The use of urease conjugated goat anti-RIgG (GaRIgG-Ur) as the labeled antibody and urea as the substrate with an amperometric detection at −200 mV (vs Ag/AgCl) resulted in a dynamic range of 50−2000 ng mL-1 and a low detection limit of 10 ng/mL (64 pM) for the immunoanalysis of rabbit immunoglobulin G (RIgG). Because of the special affinity between protein A and RIgG, the PA/NF/PrA electrode can be regenerated repetitively by changing the pH of the buffer solutions. Characteristics of the PA/NF/PrA/RIgG immunosensor and optimal conditions for the competitive immunoanalysis of RIgG with FIA were studied.