High-Efficiency Electrochemiluminescence Biosensor with Antifouling and Antibacterial Functions for Sensitive and Accurate Analysis of Chloramphenicol in Seawater

In marine environmental monitoring, due to the presence of a large number of interfering proteins and bacteria in seawater, it is of great significance to construct an efficient sensing interface with antifouling and antibacterial functions to avoid the aforementioned interferences. On this basis, the zwitterionic hydrogel based on sulfobetaine methacrylate (SBMA) and bovine serum albumin (BSA) was developed as an antifouling and antibacterial coating. The combination of hydration of zwitterions and hydrophilicity of hydrogels endows BSA@PSBMA with good antiadsorption ability, which effectively hinders the adhesion of proteins and bacteria, thereby improving the detection sensitivity of the biosensor. At the same time, the covalent grafting of SBMA and BSA solves the defect of poor stability of individual BSA in complex matrices, improving the stability and service life of the biosensor. In addition, Au@luminol was encapsulated in the zwitterionic hydrogel as an internal standard to realize a one-step integration of antifouling and ratio strategies, which simplifies the construction process of the biosensor. The developed electrochemiluminescence biosensor exhibited good sensitivity and accuracy for chloramphenicol detection, with a wide linear range of 1 pM to 100 nM and a low detection limit of 0.39 pM (S/N = 3), which is suitable for trace detection of antibiotics in seawater.