The Research Of Screen-printed Electrochemical Biosensor And Its Applications In Water Environmental Monitoring

With the appearance of low-cost and disposable screen-printed electrodes （SPEs）,electrochemical biosensor become miniature and portable gradually. Therefore, theresearch on electrochemical biosensor based on SPEs will expand the application ofbiosensors. This article aims at the whole method for the development ofelectrochemical biosensor, including fabrication of SPEs, preparation of the biosensorand measurement of electrochemical. The main contents are as follows:（1） The fabrication of SPEs: The structure of SPE was designed with threeelectrodes and the SPEs were fabricated through mechanized screen-printed techniquewhich could provide basic electrodes for the biosensors described in the work. Theresearch has also introduced the fabrication process in detail, discussed the problemsin the course of preparation and investigated the electrochemical performance of SPE.SPEs can be mass-produced at low cost and possess more application value thanconventional electrodes.（2） The primary applications of SPE: The DNA film modified SPEs wereprepared by drop-coating method and are denoted as DNA/SPE biosensor. Thecomplex of Ru（bpy）32+was used as signal molecule and cyclic voltammetry wasapplied in determining α-naphthylamine in the water. The experimental parameterswere optimized. Under the optimal conditions, the voltammetric peak currentincreased linearly with the concentration of α-naphthylamine over the range of5.0×10-7².0×10-5mol/L（r=0.996）.（3） Preparation of coreshell Fe₃O₄@Au magnetic nanoparticles modified SPEmmunosensor: the antibody of microcystin-（leucine-arginine）（anti-MCLR） wasimmobilized on the modified electrode surface by the adsorption between Aunanoparticles and the antibody to obtain the immunosensor for the detection of MCLR.The immunosensor was based on the direct competitive immunoassay format betweenthe labeled agent of horseradish peroxidase-conjugated MCLR （MCLR-HRP） and theanalyte. MCLR was determined by differential pulse voltammetry （DPV）. Under theoptimal experimental conditions, the peak current response decreased proportionallywith the concentration of MCLR over the range of0.79¹2.9μg/L with a detectionlimit of0.38μg/L.The electrochemical biosensors which were prepared in this paper exhibitedgood recovery and reproducibility when they were used to analyze practical watersamples. The biosensors have many advantages, such as high sensitivity, goodreproducibility, fast response, etc. In addition, the SPE will promote theproductization and commercialization of electrochemical biosensor and be conduciveto achieving the rapid on-site determination of the related genetic toxic pollutants.