Enhanced Atrazine Degradation Using Laccase Immobilized on Arginine-Functionalized Boron Nitride Nanosheets

Abstract

Fungal enzyme-mediated systems have been widely employed for the degradation of environmental contaminants. However, the use of free enzymes is limited by the rapid loss of their catalytic activity, stability, and reusability, which further restricts their catalytic performance. In this work, we developed an enzyme immobilization platform by elaborately anchoring the fungal laccase onto arginine-functionalized boron nitride nanosheets (BNNS-Arg@Lac). BNNS-Arg@Lac showcased enhanced stability against fluctuating pH values and temperatures, along with remarkable reusability across six consecutive cycles, outperforming free natural laccase (nlaccase). As a demonstration, a model pollutant of atrazine (ATR) was selected for proof-of-concept applications, given substantial environmental and public health concerns in agriculture runoff. By applying BNNS-Arg@Lac, the ATR degradation rate was nearly doubled that of nlaccase. Moreover, BNNS-Arg@Lac consistently demonstrated superior ATR degradation capabilities in synthetic agricultural wastewater and various mediator systems compared to nlaccase. Comprehensive product analysis unraveled distinct degradation pathways for BNNS-Arg@Lac and nlaccase, further elucidating the mechanism of the laccase-catalyzed ATR treatment. Overall, this research provides a foundation for the future development of enzymatic catalysts in tackling pollution problems and may unlock new potential for green and efficient environmental remediation and waste management strategies.