Enhancing electrochemiluminescence of porphyrin by bimetallic MOF as coreaction accelerator for dopamine determination

In this study, we present a bimetallic metal-organic framework (MOF), MIL-53(Fe/Co), as a novel and highly efficient co-reaction accelerator to enhance the electrochemiluminescence (ECL) performance of the TCPP/K₂S₂O₈ system. In stark contrast to the pristine TCPP/K₂S₂O₈ ECL system, the incorporation of MIL-53(Fe/Co) significantly improved the activation efficiency of the coreactant K₂S₂O₈, facilitating its dissociation into reactive oxygen radicals and yielding an approximately four-fold amplified ECL signal. Building upon this enhanced platform, we functionalized TCPP with 3-aminopropyltriethoxysilane (3-APBA) to create a selective recognition probe (TCPP-3-APBA) for dopamine (DA) detection. The specific diol‑boronate interactions enabled efficient DA capture, which increased steric hindrance and quenching of the ECL signal in a concentration-dependent manner. By leveraging this mechanism, we constructed a highly sensitive ECL sensor for DA quantification, which exhibited a linear range of 0.1 nM to 10 μM with a detection limit of 0.03 nM. This sensor demonstrated excellent performance in complex biological matrices, thereby expanding the applications of bimetallic MOFs in electrochemical neurotransmitter sensing.