Tetrapyrrole organics-modified cerium nanozyme with enhanced oxidase-like activity for integration of detection and degradation of antibiotic

The massive accumulation of antibiotics accelerates the emergence of antibiotic resistance causing inevitable risks to human and ecosystem. To realize the integration of detection and degradation of antibiotics, it is urgent for exploring novel nanozyme materials with the excellent catalytic activity. Integrating nanozyme with tetrapyrrole-based organics is an effective strategy to enhance the catalytic activity. Herein, a series of tetrapyrrole organics with different energy levels are severally modified on cerium oxysulfate clusters (Ce-clusters) surface to fabricate nanozyme. The mechanism of nanozyme with enhanced catalytic activity was importantly explored by the energy band matching principle. At present, there are no studies that systematically research the enhancement mechanism of tetrapyrrole-based organics with different energy levels on the catalytic activity of nanozyme. Especially, Ce-clusters modified with meso-tetra (4-carboxyphenyl) porphyrin (TCPP) has the best energy band matching, resulting in the highest catalytic activity. Remarkably, the resultant nanozyme exhibits rapid and sensitive colorimetric response to tetracycline within the range of 0-0.3 mg mL^-1, and the limit of detection was determined to 0.027 mg mL^-1. It also possesses favorable degradation performance to tetracycline under natural light with pH adaptability, strong inorganic ions and organic matter interference tolerance, high reusability, and strong stability. Its degradation efficiency is up to 97.6 % in 60 min, much higher than other types degradation strategies. This study provides a useful principle for designing highly activity nanozyme and a powerful tool to simultaneous detection and degradation of antibiotic, holding great promise for practical application.