Fabrication And Study On Amperometric Sensing Performance Of A Crown-shaped Phosphotungstate-based Multilayer Film

In this paper, two multilayer films were prepared. Firstly, thePEI/(P8W48/chitosan)n} multilayer film based on a crown-shapedphosphotungstate K28Li5H7P8W48O184·92H2O (P8W48) and cationic chitosan hasbeen fabricated on quartz, silicon, and ITO substrates via the layer-by-layer (LbL)self-assembly technique. The {PEI/(P8W48/chitosan)n} multilayer film wascharacterized reliably 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. Inaddition, the multilayer film exhibited good amperometric sensing performancetowards H2O2in a wide domain of pH1-8, which is an ideal hydrogen peroxidesensor. In pH5, this H2O2sensor has many advantages, such as a linear range of2.5×10-5to2.3×10-3M, a low detection limit of1.3μM (S/N=3), a highsensitivity of0.53mA·mM-1H2O2, and an excellent anti-interference property inthe presence of common interfering species, such as ascorbic acid, glucose, uricacid, NaNO2, KBrO3, formic acid, Na2SO3, NaNO3and acetic acid.Secondly, a multilayer film based on a crown-shaped phosphotungstateK28Li5H7P8W48O184·92H2O (P8W48) decorated by Core/Shell Cu@Agnanoparticle has been prepared on quartz, silicon and ITO substrates by the layer-by-layer self-assembly method. The growth process of the multilayer film wasmonitored by UV-vis spectroscopy, and the surface morphology and theelemental composition were surveyed by atomic force microscopy (AFM),scanning electron microscopy (SEM) and X-ray photoelectron spectra (XPS), andthe sensing performance of the multilayer film was surveyed by cyclic voltammetry (CV) measurements, respectively. In pH2.5, the {PEI/PSS-Cu@Ag/PEI/P8W48}nmultilayer film exhibited good amperometric sensingperformance towards IO3-. This IO3-sensor has a wide linear range of1.0×10-7to4.3×10-4M, a low detection limit of5.0×10-8M (S/N=3), a high sensitivityof1.4mA·mM-1IO3-, and an excellent anti-interference property in the presenceof common interfering species, such as ascorbic acid, glucose, uric acid, NaNO2,formic acid, Na2SO3and acetic acid.