In this paper, a surface plasmon resonance （SPR） sensor chip for detection of bovine serum album （BSA） was prepared by electropolymerization of 3-aminophenylboronic acid （3-APBA） based on molecularly imprinted polymer （MIP） technique. The surface morphology of MIP and non-imprinted （NIP） films were characterized by scanning electroscopy （SEM）. SEM images exhibited nanoscale cavities formed on the MIP films surface homogeneously due to the removal of BSA templates. The effects of pH, ion strength of rebinding BSA, the specific binding and selective recognition were studied for MIP films. Results indicated that the BSA-imprinted films exhibited a good adsorption of template protein （0.02-0.8 mg/mL） in 0.05 mol/L sodium phosphate buffer at pH 5.0 with the limit of detection （LOD） of 0.02 mg/mL.
A surface plasmon resonance(SPR) sensor using a molecularly imprinted polymer(MIP) film as a recognition element for detection of 2,4,6-trinitrotoluene(TNT) was developed.The TNT-imprinted polymer film was prepared by thermo initiated polymerization on the bare Au surface of an SPR sensor chip.Template TNT molecules were quickly removed with an organic solution of acetonitrile/acetic acid(9:1,v/v),causing a shift of 0.7° in SPR angle.The limit of detection for TNT was demonstrated to be as low as 1×10-8 mol/L.In the concentration range of 1×10-8-1×10-5 mol/L,the change of SPR angle was linear with the negative logarithm of TNT concentration,Selectivity studies showed that the SPR sensor had no response to TNT analogues 2,4,5-trinitrotoluene and 1,3,5-trinitrohexahydro-1,3,5-triazine at a concentration of 1×10-4 mol/L.The results suggest that the SPR sensor combined with a MIP film has the advantages of high sensitivity and selectivity,and long-term stability toward the analyte TNT.
BAO HanWEI TianXinLI XiuLiZHAO ZheCUI HeZHANG Peng
Molecularly imprinted polymer（MIP） films for hemoglobin detection were prepared onto the Au/Cr coated surface plasmon resonance（SPR） sensor chips by the in situ electropolymerization of 3-aminophenylboronic acid（3-APBA）.The formation of the films and rebinding processes of hemoglobin were monitored by in situ electrochemical-SPR（EC-SPR） spectroscopy,with allowed real-time observation of the simultaneous changes in electrochemical and optical properties of the films.Scanning electron microscopy（SEM） and atomic force microscopy（AFM）were used to characterize the surface morphologies of the MIP films.The effects of pH,ion strength,different metal ions on rebinding Hb,the specific binding and the selective recognition were investigated.The results obtained with the molecular imprinted SPR chips indicate a good adsorption of Hb in a range of 0.0005-5 mg/mL in 0.05 mol/L sodium phosphate buffer at pH=7.0.A linear calibration curve（R2=0.94） of the SPR sensor for Hb detection was obtained in a range of 0.05-5 mg/mL.The detection limit for hemoglobin by this method was 0.000435 mg/mL（S/N=3）.Interference studies indicate that the MIP films have a good selectivity compared with the referenced proteins.The stability of the sensor was also established.Results indicate that the SPR sensor chip keeps 87.6％ of its original response after 14 d of storage under dry and ambient conditions.
WANG Yang ZHANG Qingwen REN Yamin JING Lijing WEI Tianxin
