Preparation Of Environmental Hormone Bisphenol A Imprinted Polymer And Application In Sensor

Bisphenol A as typical environmental hormones is a serious threat to human health, and has attracted widespread attention in recent years. It is necessary to develop a fast, sensitive, high selective and cheap method for determining BPA in complex sample matrices. In this paper imprinted polymer was prepared via surface imprinted polymerization, multi-step swelling polymerization and mesoporous imprinting polymerization, using bisphenol A as template molecule. It has been used as sensor electrode sensitive materials. Meanwhile, the synthesis of polymer, surface properties, the character of adsorption and selectivity, and the performance of the sensor were studied. The main results of this study were as follows:1. Electrochemical sensors for bisphenol A based on surface molecularly imprinting technology and phase inversion processSurface molecularly imprinted polymer (sMIP), which has specific selectivity to bisphenol A (BPA), was synthesized using BPA as template molecules and aminated silica gel as carrier. Based on that, MIP membrane was prepared by a phase inversion process using PVC as support substratum and the amperometric sensor was constructed through immobilization of the MIP membrane on golden electrode surface by the PVC solution. The sensor displayed a good linear range of 10～120μg mL-1 under optimized pH and temperature conditions. The water samples were determined with satisfactory results.2. Preparation, characteristics and application of molecularly imprinted polymer for bisphenol A by multi-step swelling polymerizationThe product of surface imprinted polymer obtained has small adsorption capacity, so we used the traditional multi-step swelling polymerization method to prepare imprinted polymer. And then the products were mechanically mixed with graphite powder and paraffin oil, to construct carbon paste sensor. The result showed that the response of the imprinted sensor response to BPA was stronger than to the structurally similar BP. The linear range of the promise sensor is from 1.0×10-6 to 5.0×10-4 mol L-1 and a detection limit of 4.28×10-7 mol L-1.3. Surface molecularly imprinted ordered mesoporous silica:synthesis and application in bisphenol A sensingMesoporous silica possesses enormous specific surface area, and it can provide more binding/active sites compared with traditional silica. Molecular imprinted polymer synthesized by the multi-step swelling polymerization method, couldn't be easily accessed, because its binding site and imprint cavities are embedded too deeply. The imprint cavities in surface imprinted polymer are located only on the surface which has overcome that problem, and the sorption capacities are much lower. However, mesoporous silica as support would overcome these problems. Molecularly imprinted ordered mesoporous silica is synthesized by using bisphenol A (BPA) as the template and 3-aminopropyltriethoxysilane modified hexagonal structure mesoporous silica (SBA-15) as carrier. And then the products were mechanically mixed with graphite powder and paraffin oil, to constructed carbon paste sensors, the novel chemosensor for bisphenol A is prepared, which displayed enhanced sensitivity contributed by ordered mesoporous structure and excellent selectivity due to successfully molecular imprinting. The linear range of the promise sensor is from 1.0×10-7 to 5.0×10-4 mol L-1 and a detection limit of 3.22×10-8 mol L-1. The water samples are determined by it with satisfactory results.