Detection of TNT by a molecularly imprinted polymer film-based surface plasmon resonance sensor

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.