PoPD Modified ITO Based Capacitive Immunosensor for Sulphathiazole

A capacitive immunosensor for determination of sulphathaizole (STZ) has been developed on polymer coated indium tin oxide glass chip (ITO). The immunosensor chip was fabricated by polymerizing, ortho-phenylenediamine (oPD) on ITO followed by surface modification with anti-sulphathiazole antibody. The developed immunosensor chip was characterized by using Atomic force microscopy (AFM), Cyclicvoltammetry (CV) and Electrochemical impedance spectroscopy (EIS). The capacitive measurement of the developed immunosensor was performed by using EIS in spiked drinking water and milk. The developed sensor showed liner detection range 0.1-100 mu gL(-1) for STZ with a limit of detection 0.01 mu gL(-1) in water with recovery between 95-106%. The biosensor showed excellent selectivity and storage stability upto 4 weeks when preserved at 4 degrees C.