2D mesoporous silica-confined CsPbBr nanocrystals and N-doped graphene quantum dot: A self-enhanced quaternary composite structures for electrochemiluminescence analysis.

Lead halide perovskites have become a potential candidate as electrochemiluminescence (ECL) emitters owing to their appealing electronic-to-optical merits. It remains extremely challenging, however, to improve stability and enhance charge transfer. Herein, a self-enhanced superstructures was constructed by successively loading N-doped graphene quantum dot (NGQDs) and CsPbBr perovskite nanocrystals (PNCs) onto graphene supported two-dimensional mesoporous SiO nanosheets (2D mSiO-G). This special architecture ensures improved stability and accelerated charge transport, leading to efficient self-enhanced ECL between NGQDs and PNCs in a confined mesoporous structure. Additionally, using molecular imprinting (MIP) as a protective barrier, an ECL sensor with high affinity for Ochratoxin A (OTA) detection was developed, which expressed the widest linear range of 10 ng/mL to 1.0 ng/mL and the lowest detection limit of 0.2 pg/mL. This work catches a glimpse of a new generation of desirable perovskite-based ECL emitters, which would be beneficial for its further application.