Fe and Ni Dual-Atom Catalysts as High-Efficiency Coreaction Accelerators to Enhance the Electrochemiluminescence of the Carbon Dots/S ₂ O ₈ ^2– System for Assessing the Acute Myocardial Infarction Protein Marker

Herein, Fe and Ni dual-atom catalysts (DACs) (FeNi DACs)-doped carbon dots (CDs) (FeNi DACs-CDs) as novel electrochemiluminescence (ECL) emitters with outstanding ECL performance were developed for assessing the protein biomarker insulin-like growth factor-1 (IGF-1) of acute myocardial infarction (AMI). Specifically, the FeNi DACs in the CDs as high-efficiency coreaction accelerators promoted the production of abundant reactive SO₄^•- from the coreactant S₂O₈^2- for substantially enhancing the ECL performance of the FeNi DACs-CDs/S₂O₈^2- system. More importantly, compared to single-atom catalysts with only single-atom active sites, the FeNi DACs possessing dual-atom active sites synergistically enriched S₂O₈^2- on the surfaces of the FeNi DACs-CDs and catalyzed the reduction of S₂O₈^2- for generating more reactive radicals under electrical excitation, as verified by the lower adsorption energy of S₂O₈^2- on the FeNi DACs-CDs and the intensified signals in the in situ electron paramagnetic resonance spectrum of the FeNi DACs-CDs/S₂O₈^2- system, resulting in excellent cathodic ECL emission of the FeNi DACs-CDs. Furthermore, the immunoassay platform designed based on highly efficient FeNi DACs-CDs emitters sensitively detected IGF-1 with a low detection limit (limit of detection) of 0.56 fg·mL^-1, enabling the assessment of IGF-1 levels in human serum samples. This work proposes an emerging strategy for designing high-performance ECL emitters, indicating their remarkable potential in sensitive biosensing platforms for early clinical disease diagnosis.