Polyaniline modified electrodes acetylcholinesterase biosensor

Aniline was electropolymerized by cyclic voltammetry onto the surface of glassy carbon electrode (GCE) to fabricate the polyaniline (PANI) modified electrode, the modified electrode showed an excellent electrocatalytical effect on the oxidation of thiocholine (TCh). The PANI films were formed on the glassy carbon electrode (GCE) by cyclic voltammety between -0.2 and 0.9 V vs. saturated calomelelectrode (SCE), and acetylcholinesterase (AChE) was immobilized in chitosan membrane with a filter pore size of 0.45μm to prepare enzyme membrane. The enzyme membrane was then fixed on the surface of PANI/GCE with O-ring to prepare an amperometric AChE-PANI/GCE sensor for the detection of dichlorvos pesticides. The characteristics of the electrodeposition layer were observed to be dependent on the deposition time, PH, and aniline concentration. Under the optimal experimental conditions, the dichlorvos inhibition on AChE-PANI/ GCE was proportional to its concentration from 5 to 100μg/l, with the correlation coefficients of 0.9945. And the results showed high stability, good selectivity and reproducibility for determination of dichlorvos.