Construction Of Light-induced Self-Powered Electrochemical Sensing Platforms

Self-powered electrochemical sensing platforms are generally operated on the basis of energy transformation in a fuel cell which can drive the sensing progress.In this thesis,photocatalytic fuel cells were contructed by employing different kinds of photoelectrochemically active species modified electrodes.Light induced self-powered electrochemical sensors for the analysis of glucose and bisphenol A were proposed by the utilization of the contructed photocatalytic fuel cells.The main contents include the following two parts:1.A Ni?OH?₂/TiO₂ photoanode possessing high photoelectrocatalytic activity toward glucose oxidation driven by visible light was fabricated.The results indicated that deposition of Ni?OH?₂ on TiO₂ film electrode could remarkably promote the catalytic oxidation of glucose under visible light illumination.By applying a low voltage,the Ni?OH?₂/TiO₂ electrode showed a linear photoelectrochemical response to glucose in the concentration range from 0.5?mol·L^-1to 20?mol·L^-1.Furthermore,the high photoelectrocatalytic activity of Ni?OH?₂/TiO₂ electrode toward glucose oxidation was utilized to construct a glucose-air photofuel cell,which generated electrical signal responding to glucose concentration from 5?mol·L-¹ to 100?mol·L-¹,without using external electrical power supply.Thus,dual non-enzymatic glucose sensors based on photocatalytic oxidation of glucose on the Ni?OH?₂/TiO₂ electrode under visible light illumination were demonstrated.2.A light induced self-powered electrochemical sensor for bisphenol A?BPA?detection based on photocatalytic fuel cell was constructed by the use of water-soluble graphite-phase carbon nitride?C₃N₄?and the molecular imprinting polymer?MIP?.The?MIP?of bisphenol A was synthesized using 4-vinylpyridine?4-vp?as functional monomer and ethylene glycol dimethacrylate?EGDMA?as crosslinker.MIP/C₃N₄/FTO modified electrode was prepared by loading the molecularly imprinted polymer on the surface of carbon nitride.The synthesized MIP possesses the specific recognition properties for bisphenol A while carbon nitride has a large surface area and can be used as a good carrier for immobilization of molecularly imprinted polymers.Meanwhile,carbon nitride owns good photoelectrochemical activity which can catalyze the oxidation of bisphenol A under visible light irradiation.A photocatalytic fuel cell based self-powered BPA sensor was fabricated by applying the MIP/C₃N₄/FTO modified electrode as photoanode and Pt electrode as the cathode.Under the optimum experimental condition,the self-powered sensor showed a linear response between the maximum output power density of the cell and the logarithm of BPA concentration in a range from 5 to 100?mol·L^-1?R²=0.997?.Moreover,the proposed self-powered electrochemical sensor exhibited excellent specific recognition ability toward bisphenol A and could avoid the interference of other structural analogues.