Robust determination of marbofloxacin based on bimetallic Au@Ag nanoparticle-decorated black phosphorus nanosheets supported molecularly imprinted polymer film

The abuse of marbofloxacin (MBF) leaves residues in foods and environment. Therefore, developing a selective method for trace determination of MBF is of great significance. Herein, a bimetallic Au@Ag nanoparticle-decorated black phosphorus nanosheet-supported molecularly imprinted polymer film (MIP/BPNS-Au@AgNP) was fabricated for label-free and robust MBF sensing. In the presence of MBF, a polypyrrole film was grown onto the surface of BPNS-Au@AgNPs via potentiodynamic scanning. Au@AgNP functionalization prevented BPNS from degrading in aqueous solutions, enhanced its electrical conductivity, and provided a larger surface area to accommodate more selective imprinted cavities. Hence, the MIP/BPNS-Au@AgNP film demonstrated excellent electrochemical activity for MBF oxidation, including a broad linear dynamic concentration range (0.001–10 μM) and a low limit of detection (0.13 nM). Moreover, the MIP/BPNS-Au@AgNP film exhibited outstanding signal discrimination ability against potential interfering species and retained robust responses for four weeks. The MIP/BPNS-Au@AgNP film could also determine trace amounts of MBF in milk, sewage, and serum.