Coreaction Accelerator Au Nanoparticle-Confined Coordination Polymers with Highly Efficient Electrochemiluminescence...

In this study, a highly efficient electrochemiluminescent (ECL) coordination polymer, Au-Zn-DTBA, was synthesized by employing 2,2'-dithiodibenzoic acid (DTBA) as the luminescent ligand and Zn²⁺ as the metal node as well as Au nanoparticles (AuNPs) as coreaction accelerators confined to DTBA via Au-S bonds for the construction of biosensors for sensitive detection of the biomarker of neurological disease, dopamine. Compared to the Zn-DTBA ECL system without a coreaction accelerator, Au-Zn-DTBA exhibits a 4-fold enhancement in ECL intensity, since AuNPs confined in Zn-DTBA could promote the coreactant K₂S₂O₈ to produce abundant sulfate radicals SO₄^•- for significantly enhancing the ECL efficiency of Zn-DTBA. As a result, an ultrasensitive ECL biosensor employing the Au-Zn-DTBA/K₂S₂O₈ ECL system was developed for dopamine detection, achieving a low detection limit of 0.41 nM and outperforming most previously reported dopamine biosensors. This strategy demonstrates the significant potential of coreaction accelerators based on the confining effect, offering a novel approach for increasing ECL efficiency and expanding its application in clinical analysis.