Surface-enhanced electrochemiluminescence combined with resonance energy transfer for sensitive detection of microcystin-LR

The development of strategies for ultralow-content organic pollutants such as microcystin-LR (MC-LR) is critical for environmental monitoring and pollution prevention. Herein, a novel surface-enhanced electrogenerated chemiluminescence (SEECL) strategy integrated with resonance energy transfer (RET) was developed for ultrasensitive MC-LR detection. By co-modifying graphitic carbon nitride (g-C 3 N 4 ) as the donor and a core–shell nanocomposite (Au@SiO₂-Ir) as the acceptor on the electrode, the electron-transfer path was significantly shortened. Furthermore, gold nanoparticles (Au NPs) enhanced the ECL signal of the iridium complex through localized surface plasmon resonance (LSPR). After the successive introduction of ferrocene-labeled aptamer on the modified electrode, the ECL signal remarkably decreased. Upon specific recognition of the target by the aptamer, the ECL signal was restored, enabling ultrasensitive detection of microcystin-LR. The developed sensor exhibited good selectivity, ultrasensitivity, excellent stability for the determination of MC-LR, with a dynamic linear range of 1 to 10 ng/mL, and a limit of detection of about 0.86 pg/mL. The present work provides a novel way for the exploration of iridium complex in ECL realm with integrated surface enhance strategy. Graphical