Preparation Of Photoelectrochemical Sensor And Their Applications On The Determination Of Organic Pollutants

With the development of modern life standard, industrial civilization and rapid progress of production technology, environmental pollution has become one of the common concerned problems in the worldwide. Therefore, rapid determination and reliable quantification of trace level of environmental pollutions have become increasingly important. Well established methods over the past decades for organic pollutants quantification include gas chromatography, high performance liquid chromatography and capillary electrophoresis. These methods often require complicated pretreatment steps, expensive labor resources, and are not applicable for in situ analysis.A newly developed photoelectrochemical (PEC) approach may address this problem, because whether electroactive or nonelectroactive organic species can be photocatalytically oxidized and generate a photocurrent. Owing to the efficient separation of excitation source (light) and detection signal (current), the PEC sensor is considered to be a more sensitive technique with its remarkable sensitivity, portability and easy integration.Based on the above understanding, the content of this paper revolves around the photoelectrochemical detection of organic pollutants.1. Here we report a novel, highly sensitive visible-light photoelectrochemical (PEC) sensor for the detection of 2,4-D, whereby a nanocomposite of crossed bismuth oxyiodide nanoflake arrays (BiOINFs) modified with molecularly imprinted gold nanoparticles-polypyrrole polymer (MIP AuNPs-PPy) is used as a photoactive electrode. Our results demonstrate that the smart combination of BiOINFs with MIP AuNPs-PPy offers a high-performance photoactive sensing platform. The detection limit for 2,4-D is found to be as low as about 0.04 ng mL-1 (S/N= 3).2. We developed a new sensitive and selective sensor based on molecularly imprinted polypyrrole-Au coated AgI/BiOI for the photoelectrochemical (PEC) detection of Perfluorooctanoic Acid (PFOA) under visible-light irradiation. The detection limit was found to be as low as about 0.01 ng.mL-1 (S/N= 3).3. A highly sensitive and selective biosensor for the photoelectrochemical (PEC) detection of organophosphate pesticides (OPs) has been developed, whereby newly synthesized nitrogen-doped graphene(GN)/ZnSe with biomolecules acetylcholinesterase (AChE) yields a novel AChE/n-graphene/ZnSe hybrid. The detection limit was found to be as low as about 0.05 ng.mL-1 (S/N= 3).