Sensitive Determination of Nicotine on PolyNiTSPc Electrodeposited Glassy Carbon Electrode: Investigation of Reaction Mechanism

In this paper, we report an electrochemical material for nicotine detection in aqueous solution by using glassy carbon electrode (GCE) electrodeposited with Nickel(II) phthalocyanine‐tetrasulfonic acid tetrasodium salt (polyNiTSPc) in Tetra n‐bütil ammonium hydroxide (TnBAH) alkaline solution. The detection performance of the polyNiTSPc/GCE and the reaction mechanism of nicotine electro‐oxidation process is investigated using Cyclic Voltammetry (CV) and Square Wave Voltammetry (SWV) techniques in 0.1 M phosphate buffer solution (pH 7.5). The conductivity properties of the bare GCE and polyNiTSPc/GCE were analysed using Electrochemical impedance spectroscopy (EIS). The surface morphology of bare GCE and polyNiTSPc/GCE are characterized by Atomic Force Microscopy (AFM). PolyNiTSPc shows high catalytic activity for the electro‐oxidation of nicotine, with the limit of detection at 146 nM nicotine. PolyNiTSPc/GCE can be used as a biosensor with very low detection limit for nicotine. Electrode process for nicotine oxidation is diffusion controlled, including irreversible one‐electron transfer attributed to the nicotine/nicotine‐Δ1′,(5′)‐iminium ion conversion on the polyNiTSPc coated electrode. Electrochemical measurements indicated that the polyNiTSPc against nicotine plays a similar role as CYP2A6 enzyme which catalyses the intermediate reaction product of nicotine‐cotinine transformation in most mammalian species.