Low energy nitrogen ion beam implanted tungsten trioxide thin films modified indium tin oxide electrode based acetylcholine sensor

Abstract

Abstract This paper reports the fabrication of non-enzymatic acetylcholine (ACh) electrochemical sensor based on low energy nitrogen ion (100 keV) implanted tungsten trioxide (WO3) thin films modified indium tin oxide (ITO) electrode. The WO3 thin films deposited on ITO by spin coating technique was subjected to nitrogen ion implantation with the optimum fluence of 1 × 1015 ions/cm2. The implanted electrode was characterized by X-ray diffraction, field emission scanning electron microscopy (FESEM), photoluminescence spectra, Hall Effect measurements, cyclic voltammetry and amperometry. The implanted WO3 modified ITO electrode induces desirable changes in the crystal structure, surface morphology and electron mobility. Compared with pristine WO3/ITO, nitrogen ion implanted WO3/ITO displayed improved electrical conductivity and electrocatalytic activity towards ACh oxidation in 0.1 M potassium hydroxide solution (KOH). Amperometric measurements showed that the fabricated electrode had a wide linear response range of 0.1–8000 µM, higher sensitivity of 140.57 ± 0.62 mA/M/cm2 and the lowest detection limit of 28 nM, which are superior among the non-enzymatic ACh electrochemical sensors. The proposed sensor exhibits an excellent anti-interferential ability, good stability and reproducibility and successfully applied for the determination of ACh levels in human serum samples.