Triple quenching strategy-based highly sensitive electrochemiluminescence sensor for perfluorooctanoic acid

Quenching-based electrochemiluminescence (ECL) sensing boasts prominent advantages for trace analysis, while single-mechanism systems have inherent flaws, making the development of efficient synergistic quenching strategies of great practical significance for ultra-trace perfluorooctanoic acid (PFOA) detection. In this work, a zinc-coordinated perylenetetracarboxylate complex ZnPTC with coordination-induced aggregation-enhanced ECL (AIECL) performance was successfully synthesized. By adopting a triple synergistic quenching strategy, a novel ECL sensing platform was constructed based on oxygen-vacancy-rich manganese dioxide/multi-walled carbon nanotubes (Vo-MnO₂/MWCNTs). The rigid framework formed by Zn²⁺ coordination can effectively suppress non-radiative transitions and alleviate the luminescence quenching caused by π-π stacking, thus achieving efficient and stable ECL emission. The Vo-MnO₂/MWCNTs act as a multifunctional quencher through three synergistic mechanisms: (1) resonance energy transfer, (2) reactive radical scavenging, and (3) electron transfer. Specific binding of the target to the aptamer triggers dissociation of the quenching probe from the electrode surface, restoring the ECL signal for quantitative detection. The sensor shows a linear range from 2.42 × 10^-18 to 2.42 × 10^-9 mol/L, with a detection limit of 1.67 × 10^-18 mol/L (S/N = 3), as well as excellent selectivity, repeatability, and stability. Recovery in real water samples ranged from 96.5% to 103.2%, confirming the practical applicability of the method. This work provides a new ECL sensing strategy for ultratrace detection of electrochemically inactive persistent organic pollutants and offers a rational approach for the synergistic design of high-performance luminophores and quenching probes.