Bio-Inspired Laccase-Mimicking Cu3-MOF Nanozyme as Colorimetric Sensor Array for Rapid Degradation and Visual Sensing of Phenolic Compounds.

Trinuclear copper complexes that emulate the active sites of multicopper oxidases (MCOs) are of broad biological interest. Here, a monoatomic-node strategy combined with solvent reduction was used to construct a rare trinuclear copper MOF featuring a planar, equilateral-triangular CuI 0.6CuII 2.4 core. The CuI 0.6CuII 2.4-MOF nanozyme shows enzymatic activity 37.2 times than that of laccase and 13.6 times than that of a CuII 3-MOF analogue, retains high chemical stability from pH 4 to 12, and lowers production cost by 16.2-fold relative to natural laccase. DFT calculations attribute the superior performance to the introduction of Cu+, which yields a more favorable electronic structure, reaction energy landscape, and intermediate binding than in CuII 3-MOF. Consequently, CuI 0.6CuII 2.4-MOF efficiently degrades phenolic pollutants and enables colorimetric discrimination and detection of 11 phenols as a colorimetric sensor array. It also affords sensitive detection of epinephrine and dopamine, with limits of detection of 6.5 and 10 µm, respectively. Overall, this work demonstrates a laccase-inspired route to high-activity, low-cost MOFs with strong potential for environmental remediation and biosensing.