New antibodies immobilization system into a graphite-polysulfone membrane for amperometric immunosensors.
Polysulfone membrane is used for the first time for the preparation of electrochemical immunosensors. A disposable immunosensor based on a porous conductor polymer graphite-polysulfone-electrode has been developed using a phase inversion technique for the determination of anti-rabbit IgG (anti-RIgG) as a model analyte. To construct the sensor, a conductor membrane was deposited on the surface of working graphite-epoxy composite (GEC) electrode. The membrane was characterized by SEM. This sensor was based on the competitive assay between free and labeled anti-RIgG for the available binding sites of immobilized rabbit IgG (RIgG). Incubation parameters were optimized in this work. The immunological reaction was detected using an enzymatic-labeling procedure (HRP enzyme) combined with the amperometric detection using H(2)O(2) as substrate and hydroquinone as mediator. This sensor shows stability during a week and a good reproducibility. The current was monitored amperometrically at -0.1 V versus SCE and this method showed a linear range of the anti-RIgG from 1 to 6 microg/ml. The detection limit was determined to be 0.77 microg/ml.
Ordóñez
Samuel Sánchez
SS
Grup de Sensors i Biosensors, Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08113, Spain.
Fàbregas
Esteve
E
D000327:Adsorption; D000818:Animals; D000906:Antibodies / Q000032:analysis* / Q000276:immunology; D000936:Antigen-Antibody Complex / Q000032:analysis / Q000276:immunology; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006108:Graphite / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D007074:Immunoglobulin G / Q000032:analysis* / Q000276:immunology; D011108:Polymers / Q000737:chemistry*; D011817:Rabbits; D013450:Sulfones / Q000737:chemistry*
D000906:Antibodies; D000936:Antigen-Antibody Complex; D020099:Coated Materials, Biocompatible; D007074:Immunoglobulin G; D011108:Polymers; D013450:Sulfones; C017662:polysulfone P 1700; D006108:Graphite