Construction of a stable manganese/copper core-shell laccase-like enzyme for recyclable dye decolorization and phenolic pollutant detection

Abstract

Laccase shows significant potential for environmental remediation, yet its practical implementation is limited by inherent instability and restricted reusability. To address these limitations, we successfully synthesized a Mn/Cu-based core-shell structured laccase-like enzyme (SiO₂@APTCu-MnO₂) using a sol-gel method coupled with an in situ sacrificial strategy. Compared to natural laccase, SiO₂@APTCu-MnO₂ exhibited enhanced substrate affinity (Michaelis constant, K_m = 0.29 mM) and a higher catalytic rate (V_max = 1.05×10⁻³ mM/min). It maintained exceptional stability across wide pH and temperature ranges, retaining over 80% activity after 90 days. During application, the decolorization efficiency for anthraquinone and azo dyes was over 90% within 2 hours. Remarkably, it preserved over 80% of its activity and decolorization capacity for reactive blue 19 even after 10 cycles. A dye decolorization-cultivation system confirmed that the treated water had minimal impact on plant growth. Additionally, the laccase-like enzyme enabled rapid and sensitive detection of phenolic pollutants. These results indicate that SiO₂@APTCu-MnO₂ serves as a high-performance, multifunctional alternative to natural laccase in environmental remediation and pollutant detection.