Enhancing binding properties of imprinted polymers for the detection of small molecules

[摘要] This study demonstrates the promising steps towards improving the detection of small analytes in an aqueous solutionby the quartz crystal microbalance (QCM) modified with a molecularly imprinted polymer (MIP) based sensitive layer.A homogeneous thin polymer film of poly(m-phenylenediamine) (PmPD) was electrochemically deposited on the surface ofa QCM sensor in the presence of sulphamethizole (SMZ) acting as a template molecule. The binding capacity of the resultingSMZ–MIP films was enhanced by modifying the sensing surface with a diethylaminoethyl-dextran (DEAE-Dex) layer, forminga SMZ–MIP(Dex) film. The dextran layer allows further preconcentration of template molecules on the sensor electrode beforepolymer electrodeposition. The relative adsorption of the SMZ–MIP(Dex) films, as designated by the imprinting factors, wasfound to be in all cases significantly higher than that of the other films. At least about three times enhanced relative bindingcapacity of the modified imprinted polymer on the QCM sensor was established. A probe of the analysed sensor signals revealedthat the modification steps significantly reduced the contribution from nonspecific interaction of the polymer matrix, thussuggesting beneficial effects of the dextran modification and template preconcentration. The presented approach promises apositive route towards an improved specific detection of small molecules by molecular imprinting on QCM sensor transducers.

[学科分类] 化学（综合）

[关键词] molecularly imprinted polymer;small molecule detection;sulphamethizole;quartz crystal microbalance;DEAEdextran.