Molecularly imprinted-SPR sensor for detecting melamine in dairy products based on signal enlarger by Au nanoparticles

A molecularly imprinted-surface plasmon resonance (MIM-SPR) sensor for detecting melamine in dairy products was build by molecular imprinting and SPR signal enlarger technique, and the recognition element of this sensor was molecular imprinted membranes embedding with Au nanoparticles. First of all, the molecularly imprinted membranes embedding with Au nanoparticles were synthesized on the SPR gold chips through surface-initiated thermal polymerization, and then the response, selectivity, reproducibility and accuracy of the MNM-SPR sensors were evaluated respectively. The calibration curve of this detecting methods had showed good linearity (R2=0.998) , when the concentration of melamine ranged from 1×10-2μg/m L to 2μg/m L, and the recoveries were 86.43%¹07.11%, when the spiked concentration ranged from 0.5μg/m L to 1.5μg/m L, and RSD less than 6.0% ( n =5) . The results suggested that this method was easily operated, selective, reproducible, accurate and applicable for detecting melamine residue in dairy products.