Polydopamine-stabilized CsPbBr3 enables toxicity-reduced ECL detection of MMP-2 via CRISPR/Cas12a trans-cleavage

Lead-halide perovskites offer bright electrochemiluminescence (ECL) but suffer from aqueous instability and Pb 2+ safety concerns. We construct a CsPbBr 3 @PDA–Au nanointerface that couples polydopamine (PDA) passivation with Au-assisted charge transfer, integrated into a peptide-to-CRISPR/Cas12a amplification scheme for ultrasensitive detection of matrix metalloproteinase-2 (MMP-2). PDA conformally coats CsPbBr 3 , suppressing trap-mediated quenching and mitigating Pb 2+ release, while providing catechol/amine anchors for a tetrahedral DNA scaffold bearing a ferrocene-labeled hairpin. Upon MMP-2 cleavage of a GPLG↓VRG peptide–DNA chimera, the released strand activates Cas12a trans-cleavage, removing the proximal quencher and switching the interface from “off” to “on.” Under unified processing (baseline subtraction and renormalization), the platform achieves a 5.6 aM detection limit with high selectivity over non-target proteases and excellent inter-device reproducibility (triplicate error bars reported). TEM/HRTEM visualize uniform nanocubes; XPS/FTIR evidence PDA catechol/quinone/amine coordination; XRD confirms phase-pure CsPbBr 3 ; and corrected CV/EIS analyses verify accelerated interfacial kinetics after Au decoration. The sensor retains ∼98 % intra-day and ≥91 % 7-day signal, supporting operational robustness. By integrating interfacial stabilization, catalytic electron transfer, and molecular amplification, this modular design advances eco-conscious, perovskite-based ECL diagnostics for low-abundance protease monitoring and broader clinical bioanalysis.