Hybrid peptide-molecularly imprinted polymer interface for electrochemical detection of vancomycin in complex matrices.

A hybrid recognition interface combining peptide and molecularly imprinted polymer (MIP) was achieved by introducing a vancomycin binding tripeptide in the preparation of MIP to implement high affinity and specificity recognition of vancomycin in complex matrices. The tripeptide that can specifically bind vancomycin was immobilized onto gold nanoparticles (GNPs) deposited on a glassy carbon electrode (GCE) by Au-S bond, and then a controlled electropolymerization of dopamine was carried out to imprint the vancomycin-peptide complex. After removing vancomycin from the polydopamine (PDA), hybrid peptide-MIP cavities containing multiple binding sites for vancomycin in the MIPDA/peptide/GNPs/GCE were obtained. The electrode had better selectivity and higher sensitivity toward vancomycin than either peptide or MIP modified GNPs/GCE, and the limit of quantification was as low as 10 pM by electrochemical impedance spectroscopy. The real samples, including fetal calf serum, probiotic drink and honey spiked with 0.17-2.0 μM vancomycin were analyzed on the MIPDA/peptide/GNPs/GCE, with the recoveries of 92.16-104.67%. The present study provides a sensitive, reliable method for the detection of vancomycin in complex matrices.