Study Of Sensing Material Based On Hybrid Molecularly Imprinted Polymer

Based on electrochemically driven cross-linking a pendant polymer precursor, a composite constituting by self-assembing the thiolated polymer precursor with Au nanoparticles, we have prepared novelty molecular imprinted sensing materials using L-Phenylalanine and adenosine as template, respectively In the experiment, we have studied the synthsis conditions and methods of the pendant polymer, the electrochemical polymerization conditions, characterization of the sensing materials and the performance of the MIP sensors. The main contents of this paper are showed as follow:1. Hybrid Chiral Molecularly Imprinted Film:Preperation, Characteration and ApplicationA novel chiral molecularly imprinted polymer (MIP) sensing material for L-Phenylalanine has been developed, which is constructed by electrochemically driven cross-linking a pendant polymer precursor, poly[2-(N-carbazolyl)ethyl methacrylate-co-meth-acrylic acid]s (PCEMMAs). In this MIP sensing material, the recognition sites, the insulating polymethylacrylic acid (PMAA), were covalently bonded to the conducting polycarbazole which could be used as signal transfer interface between recognition layer and electrode. The mole ratio of copolymerizing monomers,2-(N-carbazolyl) ethyl methacrylate:methylacrylic acid (CE:MAA), and the scanning cycles of electropolymerization were adjusted during the preparation of MIP sensing material. The optimized conditions, CE:MAA=3:2and20scanning cycles, were obtained. And then the properties of MIP films were characterized by atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS) and water contact angle. Open circuit potential-time technique was used to estimate the enantioselectivity of the MIP sensor. The results indicate that the promising sensor preferentially responses L-Phenylalanine (L-Phe) over D-Phenylalanine (D-Phe) with a selectivity coefficient KDL=5.75×10-4and the limit of detection (LOD) is1.37μmol·L-1, which reveals its good enantioselectivity and sensitivity.2. The Composite Sensing Material of Hybrid Molecularly Imprinted Polymer-AUNPs:Preperation, Characteration and ApplicationThe electropolymerization of the thiolated pendant polymer self-assembling with AuNPs in the presence of adenosine results in a molecular-imprinted matrix for the recognition of adenosine. In this sensing material, the molecular-imprinted site enabled the high selectivity for adenosine and Au nanoparticles could catalyze the oxidation of adenosine, which results in material with biomaterial-like properties, specificity and high efficiency, such as enzyme and antibody. The material was characterized by different methods including AFM, and SEM means. And differential pulse voltammetry (DPV) technique is used to estimate the performance of the sensor. Compare with the MIP sensor, the results indicate that the MIP-Au sensor has better catalysis for adenosine detection, and the MIP-Au sensor shows good selectivity, the limit of detection (LOD) is0.17μmol·L-1.