Dual-Component Ratiometric Fluorescent Platform Constructed by Gold Nanoclusters and Cerium-doped Terbium-based Metal-organic Framework for Microcystin-LR Detection.

Ratiometric fluorescence sensing is effective for environmental pollutant monitoring owing to self-calibration and anti-interference properties, but high-sensitivity and high-specificity probes for microcystin-LR (MC-LR) are still scarce. Herein, GP-AuNCs@Ce/Tb-BTC (Ce/Tb metal-organic framework based on benzene-1,3,5-tricarboxylic acid) was developed as a novel ratiometric fluorescent probe for aquatic MC-LR. Coordination interaction and suppressed non-radiative relaxation strengthen its fluorescence response, while dual-fluorescence ratiometric self-calibration optimizes detection stability. The optimized GP-AuNCs@Ce/Tb-BTC probe exhibits excellent sensing performance toward MC-LR, displaying a favorable linear response in the concentration range of 0.02-0.1 µg/mL with a low limit of detection (LOD) of 0.006 µg/mL, as well as outstanding selectivity and anti-interference capability. Practical water sample detection results verify the favorable accuracy and precision of this detection method, with spike recoveries ranging from 91.10% to 111.0%, which is suitable for the detection in complex water matrixes. This facile and reliable sensing strategy offers a feasible strategy for MC-LR analysis in environmental water samples, with promising potential for trace detection of environmental pollutants.