Bromoperoxidase mimicry based on Bi2O2.33 nanosheets for aptasensing

To pursue new nanozyme mimetics with extended applications is appealing. Herein, Bi2O2.33 nanosheets were revealed as an efficient bromoperoxidaseand iodoperoxidase- mimetics with good catalytic capabilities for the bromination of phenol red (PR) and the iodination of thymol blue (TB) in the presence of H2O2, accompanied by the development of a ratiometric colorimetric signal. Exampled by the aptasensing of aflatoxin B1 (AFB1) as a model, a label -free, ultrasensitive, and selective ratiometric colorimetric sensing platform was constructed, achieving a low detection limit of 0.33 ng/mL. This work features a novel bromoperoxidaseand iodoperoxidase mimetic based on Bi2O2.33 nanosheets, which may arouse more interest in the exploration of haloperoxidase nanozymes with extended biosensing applications.