Heterojunction-Mediated Dual-Site Synergistic Catalysis for Enhanced Electrochemiluminescence Detection of α-Synuclein.

Precise quantification of α-synuclein (α-Syn), an important species associated with Parkinson's disease and related neurodegenerative disorders, is of paramount importance for early diagnosis and intervention. While electrochemiluminescence (ECL) has emerged as a powerful analytical technique owing to its low background interference and high sensitivity, the performance of MOF-based ECL systems is often limited by sluggish interfacial charge transfer and insufficient co-reactant activation at a single type of catalytic site. To overcome these bottlenecks, a two-dimensional (2D) ZnCu metal-organic framework/TiO2 (ZCMT) heterojunction sensing system was constructed by coupling interface engineering with a dual-site synergistic catalysis strategy. Specifically, the heterojunction facilitates directional charge transport by promoting electron delocalization and interfacial charge redistribution. Concurrently, the Cu- and Ti-based redox-active centers synergistically facilitate K2S2O8 activation and accelerate its reduction. This synergistic mechanism substantially enhances its ECL performance. By integrating the ZCMT platform with DNAzyme-assisted amplification strategy, a high-performance ECL biosensor was constructed for the ultrasensitive quantification of α-Syn. Overall, this study provides an effective strategy for overcoming the charge-transfer and catalytic limitations of MOF-based ECL systems and establishes a promising platform for the ultrasensitive analysis of α-Syn, with potential applications in the early screeningof Parkinson's disease.