Construction of biomass carbon dots@molecularly imprinted polymer fluorescent sensor array for accurate identification of 5-nitroimidazole antibiotics

Abstract

The fluorescence sensor array platform is a good choice for detection of 5-Nitroimidazole antibiotics (5-NDZs) in river water samples. However, worrisome selectivity issues inherent in fluorescent sensing units limit their general use in complex samples. In order to solve this problem, we prepared biomass carbon dots based on the catalpa walnut shells by hydrothermal method and formed molecularly imprinted polymers on the surface of carbon dots (CDs@MIPs) by sol-gel process. The cavities of CDs@MIPs enable the exposed binding sites to specifically capture the template molecules, thereby greatly improving the selectivity for 5-NDZs molecules. Different identification materials interacting to varying degrees with 5-NDZs were used to distinguish metronidazole, ornidazole, tinidazole, and secnidazole. The fingerprints were constructed with the information of fluorescence variation degree and the signals were analyzed by linear discriminant analysis. This fluorescence sensor array can sensitively identify these 5-NDZs in a wide range (20–5000 nM). In differential testing, the array platform achieved 100% recognition accuracy for 5-NDZs in buffer solutions and spiked water samples. This protocol not only provided an accurate and simple method for the detection of 5-NDZs in river water samples, but also made a positive contribution to environmental analysis.