Study on amperometric sensing performance of a crown-shaped phosphotungstate-based multilayer film

A multilayer film based on a crown-shaped phosphotungstate K28Li5H7P8W48O184·92H2O (P8W48) and cationic chitosan has been fabricated on quartz, silicon, and ITO substrates via the layer-by-layer (LbL) self-assembly technique. The {PEI/(P8W48/chitosan)n} multilayer film was characterized by UV–vis spectroscopy, atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and cyclic voltammetry (CV) measurements. The multilayer film exhibited good amperometric sensing performance toward H2O2 in a wide domain of pH 1–8. In pH 5, this H2O2 sensor has a linear range of 2.5 × 10−5 to 2.3 × 10−3 M, a low detection limit of 1.3 μM (S/N = 3), a high sensitivity of 0.53 mA mM−1 H2O2, and an excellent anti-interference property in the presence of common interfering species, such as ascorbic acid, glucose, uric acid, NaNO2, KBrO3, formic acid, Na2SO3, NaNO3 and acetic acid.