Supramolecular Organic Framework–Enabled AIE-Enhanced Electrochemiluminescence: Dual-Readout Ultrasensitive Determination of Microcystin-LR in Environmental Waters

Accurate monitoring of microcystin-LR (MC-LR) in complex water matrices is critical for environmental safety but remains challenging due to the limited sensitivity and stability of traditional methods. Conventional electrochemiluminescence (ECL) emitters often suffer from aggregation-caused quenching (ACQ) in aqueous environments. To overcome this, we engineered a highly efficient aggregation-induced electrochemiluminescence (AIECL) emitter using a supramolecular confinement strategy. A shape-tunable supramolecular organic framework (SOF), tetrakis(1-carboxyethylpyridinium) tetraphenylethylene derivative@cucurbit[8]uril (TPE-CEPy@CB[8]), was constructed via host–guest interactions, which enhanced ECL efficiency by restricting the intramolecular motion (RIM) of the luminophore. Based on this SOF, a robust “on–off–on” biosensor was developed utilizing ECL resonance energy transfer (ECL-RET). The system incorporated target-triggered entropy-driven DNA amplification (EDA) and a Zn 2+ -activated DNAzyme, enabling simultaneous signal amplification and DNA recycling. Operational feasibility was confirmed through ECL images, which allowed intuitive visualization of concentration-dependent ECL variations, thereby achieving dual-readout detection based on both signal intensity and images analysis. Under optimal conditions, the biosensor demonstrated a broad dynamic range from 0.01 to 100.0 ng mL –1, with ultralow detection limits of 1.35 pg mL –1 via ECL intensity detection and 1.45 pg mL –1 via ECL images analysis. Crucially, the method demonstrated excellent accuracy in real environmental waters, with results highly consistent with standard high-performance liquid chromatography (HPLC) analysis. This work presents a superior dual-readout AIECL strategy that effectively mitigates matrix interference, providing a reliable avenue for the precise monitoring of trace environmental pollutants.