A combination of polypeptide and magnetic molecular imprinted electrochemical sensor based on BSA-AuNPs/Fe3O4@ZIF-8 for the detection of norfloxacin

Norfloxacin (NOR) is now extensively used for the treatment of human and animal diseases. Unfortunately, large accumulations of NOR will pose a significant threat to the human body. Thus, it is urgent to develop a rapid and sensitive detection technique for the trace determination of NOR. In this study, an electrochemical molecular imprinting sensor with great properties was fabricated for the determination of NOR in milk and environmental water. The incorporation of bovine serum proteins produced a hybrid recognition interface consisting of molecularly imprinted polymers and peptides that provided good recognition properties for norfloxacin. The Fe3O4@ZIF-8 was distributed orderly on the electrode after the embedding of the magnets inside the electrode, then the BSA was coated on the electrode with the electrodeposited AuNPs through Au-S bonding. The sensor constructed in this study achieved ultra-sensitive detection of norfloxacin with an effective area of 0.08433 cm2, a limit of detection (LOD) of 0.108 pmol·L−1, and a wide linear range (1 ∼ 100, 100 ∼ 1000 and 1000 ∼ 8000 pmol·L−1). The prepared sensors exhibited satisfactory performance in the detection of milk and environmental water, with acceptable recoveries ranging from 96.24 % to 104.88 %, and the relative standard deviation (RSD) was no more than 4.84 %.