Confined Gold Single Atoms–MXene Heterostructure-Based Electrochemiluminescence Functional Material and Its Sensing Application

Herein, based on electronic metal–support interaction (EMSI), a gold single atom confined MXene (AuSA/MXene) heterostructure was developed as the highly efficient electrochemiluminescence (ECL) functional material, which greatly improved the electrochemical properties and broadened the sensing application of MXenes. Gold single atoms were confined into the vacancy defects of Ti3C2Tx MXene, which could effectively avoid the masking of catalytic active sites. Meanwhile, electron transport could be accelerated with the assistance of titanium dioxide on the MXene nanosheets. Therefore, the AuSA/MXene heterostructure had high catalytic activity and electrical activity to promote hydrogen peroxide to generate free radicals, which achieved high-efficiency ECL. Eventually, the AuSA/MXene heterostructure was used to construct a Faraday cage-type ECL sensor with fluid nanoislands to detect miRNA-187 in triple-negative breast cancer tumor tissues.