A sensitive sandwich-type electrochemical aptasensing platform based on Ti3C2Tx/MoS2/MWCNT@rGONR composites for simultaneous detection of kanamycin and chloramphenicol in food samples

A Ti₃C₂T_x/MoS₂/MWCNT@rGONR nanocomposite was prepared for the first time for building a sensitive electrochemical aptasening platform to simultaneously detect kanamycin (Kana) and chloramphenicol (Cap). Owing to their accordion-like structure, rich surface groups, and high charge mobility, Ti₃C₂T_x/MoS₂/MWCNT@rGONR composites provided a spacious covalent immobilization surface and a better electrochemical aptasensing platform. The aptamers of Kana and Cap used in sensors enhance the selectivity. Furthermore, TiP, an ion exchanger, was used for loading more different metal ions functioning as labels to form a sandwich-type sensor together with Ti₃C₂T_x/MoS₂/MWCNT@rGONR, improving the electrochemical sensitivity and obtaining a highly distinguishable signal readout. Under the optimized conditions, the sensor has good detection limits of 0.135 nmol L^-1 and 0.173 nmol L^-1 for Kana and Cap, respectively, at the same linearity concentration of 0.5-2500 nmol L^-1. Finally, it was successfully applied for detection in milk and fish meat, and the results were compared with the standard method HPLC, indicating its great potential for food safety monitoring.