Aggregation-induced electrochemiluminescence resonance energy transfer with dual quenchers for the sensitive detection of prostate-specific antigen

Abstract

Here, gold nanoclusters (AuNCs) were wrapped with 6-aza-2-thiothymine (ATT). The aggregation of AuNCs protected by ATT induced the electrochemiluminescence (ECL) enhancement of AuNCs. A new dual-quenching ECL immunosensor based on a solid-state ATT−AuNCs (SS−ATT−AuNCs) luminophore and aggregation-induced emission (AIE) was designed for the sensitive determination of prostate-specific antigen (PSA). The synthesized CeO2-PEI@Ag composite could be used as the carrier to immobilize secondary antibody (Ab2) and also to improve the efficiency of the ECL sensing platform based on resonance energy transfer between SS−ATT−AuNCs and CeO2-PEI@Ag. Under the optimal conditions, the prepared dual-quenching aggregation-induced electrochemiluminescence resonance energy transfer (AIECL-RET) immunosensor showed a linear range from 1 × 10−5 ng/mL to 200 ng/mL and a detection limit of 2.2 fg/mL (S/N = 3). The prepared AIECL-RET sensor was successfully applied to detect PSA in human serum with high stability and good selectivity. This study enriches ECL research strategies, provides a feasible method for basic clinical testing, and shows the potential applications of ECL sensors in clinical bioassays.