Development of an Aptamer-Based Surface Plasmon Resonance Biosensor for Detecting Chloramphenicol in Milk

Surface plasmon resonance (SPR) biosensors have been applied in various fields with the advantages of being label-free, having high specificity, having high sensitivity, and providing real-time monitoring. With the gradual improvement of SPR technology, SPR biosensors have been used for the detection of macromolecules such as proteins, peptides, and nucleic acids. Antibodies are generally used as the recognition component of SPR biosensors due to the high specificity of antibody-antigen binding. Recently, aptamers have become new choices instead of antibodies for their characteristic of high specificity with target molecules, high stability of chemical synthesis, convenience in storage, and ease of labeling. In this study, an aptamer-based SPR biosensor for chloramphenicol (CAP) detection was established through optimizing the conditions of CAP aptamer immobilization and analysis procedure, including biosensor type, signal enhancement, running buffer, sample diluent, and dissociation time. The results suggested that the optimal immobilization strategy of aptamers on the SPR biosensor was indirect immobilization based on the CM5 chip. The aptamer-based SPR biosensor had good specificity for CAP and could be used to detect CAP in real samples such as milk. Therefore, SPR biosensors have great application prospects in the food safety field, and aptamers deserve further study to improve the performance of the biosensor.