Nanozyme Microgels: Multifunctional Tools for Dilute Carbon Dioxide Detection and Environmental Remediation

Inspired by the diversity of natural metalloenzymes, we designed microgels incorporating metal centers that mimic carbonic anhydrase for efficient CO₂ capture and detection, even in aqueous environments. These microgels demonstrate high sensitivity, detecting CO₂ at concentrations as low as 300 ppm, surpassing conventional methods. The metal centers in the microgels can be constructed by coordinating with metal ions such as Mn²⁺, Cr³⁺, Ni²⁺, Cu²⁺, and Zn²⁺. Upon absorption of CO₂, the system becomes weakly acidic, enabling multifunctional applications. Notably, Cu²⁺-based microgels display catalytic versatility, acting as carbonic anhydrase in neutral to alkaline conditions and as laccase or peroxidase in neutral to acidic environments. This versatility highlights their potential for transforming water pollutants across a broad pH range, offering significant promise for environmental remediation.