Cobaltous sulfide/S-doped Ti3C2 MXene nanocomposites with coreaction acceleration effect for high-performance luminol electrochemiluminescence sensing by coupling micro-nano bubbles-mediated amplification strategy

Exploration of a feasible method to enhance dissolved oxygen (DO) content and design a supplementary accelerator to accelerate the reduction efficiency of DO in the luminol-DO system was significantly meaningful for developing a high-performance electrochemiluminescence (ECL) sensing platform. Herein, a novel luminol-DO ECL system was designed by coupling the micro-nano bubbles (MNBs) and CoS2/S-Ti3C2 heterostructure for sensitive detection of chloramphenicol (CAP). Specifically, the introduction of MNBs could increase the DO content in PBS solution and the special conditions caused by MNBs rupture generated abundant reactive oxygen species (ROS). Meanwhile, CoS2/S-Ti3C2 could be used as advanced co-reaction accelerator to accelerate the reduction efficiency of DO, which could produce more ROS. Remarkably, the ECL intensity of the as-fabricated system not only revealed an 8.7-fold enhanced signal, but also displayed a more stable ECL signal compared to individual luminol-DO system. With the assistance of CAP aptamer, the as-fabricated luminol − DO system exhibited a wide linear range from 0.1 fM to 10 pM with an ultra-low detection limit of 105 fM (S/N = 3), and it performed excellent stability, reproducibility and sensitivity, so as to be applied to real sample monitoring. This strategy not only provided a new avenue to design more efficient MXene-based co-reaction accelerator, but also paved the way for the development of high-performance luminol − DO ECL system.