Disposable amperometric immunosensor system for rabbit IgG using a conducting polymer modified screen-printed electrode.
A disposable and mediatorless immunosensor based on a conducting polymer (5,2':5'2"-terthiophene-3'-carboxylic acid) coated screen-printed carbon electrode has been developed using a separation-free homogeneous technique for the detection of rabbit IgG as a model analyte. Horseradish peroxidase (HRP) and streptavidin were covalently bonded with the polymer on the electrode and biotinylated antibody was immobilized on the electrode surface using avidin-biotin coupling. This sensor was based on the competitive assay between free and labeled antigen for the available binding sites of antibody. Glucose oxidase was used as a label and in the presence of glucose, H(2)O(2) formed by the analyte-enzyme conjugate was reduced by the enzyme channeling via HRP bonded on the electrode. The catalytic current was monitored amperometrically at -0.35 V vs. Ag/AgCl and this method showed a linear range of RIgG concentrations from 0.5 to 2 microg/ml with standard deviation +/-0.0145 (n=4). Detection limit was determined to be 0.33 microg/ml.
Darain
Farzana
F
Department of Chemistry, Pusan National University, 609-735, Pusan, South Korea.
Park
Sang-Un
SU
Shim
Yoon-Bo
YB
D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002264:Carboxylic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis / Q000737:chemistry; D004209:Disposable Equipment; D004553:Electric Conductivity; D004563:Electrochemistry / Q000295:instrumentation* / Q000458:organization & administration; D004566:Electrodes; D004800:Enzymes, Immobilized; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005949:Glucose Oxidase / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007074:Immunoglobulin G / Q000032:analysis*; D010781:Photography / Q000379:methods; D011817:Rabbits; D013696:Temperature
D002264:Carboxylic Acids; D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D007074:Immunoglobulin G; D006861:Hydrogen Peroxide; D005949:Glucose Oxidase