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

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 Cu^I _0.6Cu^II _2.4 core. The Cu^I _0.6Cu^II _2.4-MOF nanozyme shows enzymatic activity 37.2 times than that of laccase and 13.6 times than that of a Cu^II 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 Cu^II ₃-MOF. Consequently, Cu^I _0.6Cu^II _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.