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 Zn2+-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.