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

Inspired\nby the diversity of natural metalloenzymes, we designed\nmicrogels incorporating metal centers that mimic carbonic anhydrase\nfor efficient CO<sub>2</sub> capture and detection, even in aqueous\nenvironments. These microgels demonstrate high sensitivity, detecting\nCO<sub>2</sub> at concentrations as low as 300 ppm, surpassing conventional\nmethods. The metal centers in the microgels can be constructed by\ncoordinating with metal ions such as Mn<sup>2+</sup>, Cr<sup>3+</sup>, Ni<sup>2+</sup>, Cu<sup>2+</sup>, and Zn<sup>2+</sup>. Upon absorption\nof CO<sub>2</sub>, the system becomes weakly acidic, enabling multifunctional\napplications. Notably, Cu<sup>2+</sup>-based microgels display catalytic\nversatility, acting as carbonic anhydrase in neutral to alkaline conditions\nand as laccase or peroxidase in neutral to acidic environments. This\nversatility highlights their potential for transforming water pollutants\nacross a broad pH range, offering significant promise for environmental\nremediation.