Cobalt-doped ZIF-8 nanozyme with bifunctional catalytic activity for integrated monitoring and remediation of sulfadiazine contaminants.

Sulfadiazine (SD) residues pose threats to ecosystems and public health, necessitating precise detection and efficient degradation. This study synthesized a cobalt-doped metal-organic framework (Co/ZIF-8) nanocatalyst with a structure mimicking human carbonic anhydrase II (hCAII) through the synergistic reaction of Zn2+ and Co2+, exhibiting a Michaelis constant of 0.11 mM. This nanozyme enables both highly sensitive colorimetric detection of SD (linear range: 6.3-950.0 μM, detection limit: 3.2 μM) and activation of H2O2 to generate ·OH for SD degradation, achieving complete degradation of 10 mg/L SD within 35 min at pH 5.0. The nanozyme exhibits excellent cyclic stability, demonstrating reliable SD recovery in real-world samples such as milk and lake water. By integrating SD detection with remediation technology, it provides a practical platform for addressing SD contamination in environmental and food contexts.