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

A multilayer film based on a crown-shaped phosphotungstate K 28 Li 5 H 7 P 8 W 48 O 184 ·92H 2 O (P 8 W 48 ) and cationic chitosan has been fabricated on quartz, silicon , and ITO substrates via the layer-by-layer (LbL) self-assembly technique. The {PEI/(P 8 W 48 /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 H 2 O 2 in a wide domain of pH 1–8. In pH 5, this H 2 O 2 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 H 2 O 2 , and an excellent anti-interference property in the presence of common interfering species, such as ascorbic acid , glucose, uric acid , NaNO 2 , KBrO 3 , formic acid , Na 2 SO 3 , NaNO 3 and acetic acid.