The Study On The Surface Plasmon Resonance Sensor Based On Electrochemical Synthetized Molecularly Imprinted Polymer Films

Surface plasmon resonance (SPR) is a new biochemical analytical technology whichhas been wildly employed in the study of biochemical, chemical, and environmentaldetection. SPR sensors have the advantage of label-free, real-time monitoring, fast responseand high sensitivity. Molecularly imprinted polymers (MIPs) are artificial materials whichsimulate the natural antigen-antibody system. The selective recognition of the MIPs isobtained by the recognition sites formed in the cavities during the polymerization. MIPscan be used in harsh environment such as acid solution, basic solution, organic solvent.Therefore MIPs technique has been taken as one of the best methods in modifiying the SPRsensor chips. In addition, the MIPs have the advantages of costing cheap, good reusabilitycompared with traditional reagents such as antigen-antibody, enzyme etc. Therefore theMIPs modified SPR sensors are expected to replace the traditional methods of modifiyingSPR sensors in biochemical detection. In this article, the MIP films for various targetmolecules have been parepared by electrochemisty combined with SPR sensors, the maincontents are as the following:1. The MIP films for detection of testosterone molecules were prepared by continuouspolymerization based on electropolymerization in acetonitril solution. The MIP films werefirst set into0.2mol/L Na2HPO4solution and overoxidized at+1.3V for2min. Then thetemplate molecules were removed from the MIP films by acetonitrile solution. Theselectivity of the MIP films for the target molecules were performing by SPR detection andresults indicated that the MIP films showed a good sensitivity of testosterone molecules.The MIP films also showed a good selectivity toward progesterone which is similar to itsstructure with a higher concentration of10-5mol/L.2. It was difficult to remove the template molecules from the MIP films by generalrising methods. Therefore the preparation process of the MIP films should be improved bya new method. The porous MIP films of testosterone were prepared in acetonitrile solutionby multistep electropolymerization, employing pyrrole as a functional monomer. Results ofSPR detection indicated that the template molecules were easy removed from the MIP filmswhich prepared by multistep electropolymerization in the molar ratio of1:8(template:monomer=1:8). The MIP films showed a good sensitivity and selectivity toward targetmolecule and its structural analytes. The sensitivity of the MIP films toward testosterone molecules in buffered solution were obtained by SPR detection. Results indicated that theSPR angular response increased as the ion strength increased. The testosterone moleculeswere easy to enter into the MIP films as the MIP films swelled in a higher concentration ofion strength buffered solution.3. Molecularly imprinted polymer films for hemoglobin (Hb) and bovine serumalbumin (BSA) were prepared onto SPR sensor chips by the in situ electropolymerizationof3-aminophenylboronic acid (3-APBA). Scanning electron microscopy (SEM) was usedto characterize the surface morphologies of the MIP films. The target proteins could passthrough the nanoscale passages during the recognition process. The effects of pH and ionstrength were studied, and the best rebinding environments toward Hb and BSA wereobtained respectively. Results indicated that the MIP films of Hb and BSA showed goodsensitivity and selectivity toward target proteins. The MIP films were easily prepared andcontroled by this method with good stability.