Synthesis of phenylalanine/manganese-copper supramolecular sheets with laccase-like activity for the detection of phenolic pollutants

Enzyme mimics with laccase-like activity showing excellent stability and tolerance have attracted extensive interest in phenolic pollutants treatment. Herein, we presented a mild and convenient strategy for the preparation of laccase-like sheets (denoted as Mn-F-Cu) inspired by the supramolecular self-assembly of the transition metals manganese, copper, and L-phenylalanine (F) under room temperature, alkaline conditions. The Mn-F-Cu sheets perform a better substrate affinity (Michaelis constant, K-m = 0.65 mM) and a higher reaction rate (V-max = 3.98 x 10(-3) mM<middle dot>min(-1)) at 25 degrees C, pH 6.8 compared to natural laccase (K-m = 1.08 mM; V-max = 6.93 x 10(-6) mM<middle dot>min(-1)). Besides, the catalytic stability data show they also exhibit good tolerance under alkaline pH (pH 8-10) and high temperature (70-90 degrees C). More importantly, the prepared Mn-F-Cu material shows a relatively better sensitivity in detecting phenolic pollutants 2,4-DP and catechol than other laccase mimics mentioned in the literature, with a detection limit of 2.41 mu M and 3.49 mu M, respectively(R-2 > 0.99). Therefore, Mn-F-Cu sheets show great potential to replace natural laccase for the detection and treatment of phenolic pollutants in harsh environments.