Synergistic iron single/diatomic nanozyme-based colorimetric filtration valve for real-time detection and degradation of kitchen wastewater contaminants

Abstract

Conventional single-atom nanozyme materials often exhibit limited enzyme-like activities and substrate specificity, making it challenging to meet the integrated demands for simultaneous detection and purification in environmental applications. In this study, we developed a novel nanozyme system featuring single/diatomic synergistic iron active sites (sdsFeN@G). sdsFeN@G exhibits superior multi-enzyme activities (POD, OXD, Laccase), outperforming natural enzymes in catalytic efficiency. Density functional theory (DFT) calculations revealed that the Fe-N four-coordination bonding shifted the d-band center of Fe closer to the Fermi level, enhancing the catalytic activity of the single/diatomic synergistic active sites. The colorimetric sensor platform integrating sdsFeN@G as the active component exhibited a detection limit as low as 0.992 μM and, leveraging its Laccase-like activity, achieved effective degradation of these antioxidants with a maximum degradation rate of 80 % for kitchen wastewater. To meet the real-time detection and purification needs in practical kitchen wastewater discharge processes, a convenient detection/purification integrated kitchen wastewater filtration valve was designed based on the sdsFeN@G nanozyme. This work advances the development of multi-enzyme active nanozyme materials, providing a promising strategy for addressing real-world environmental protection challenges.