Fabrication of bio-mimic nanozyme based on Mxene@AuNPs and molecular imprinted poly(thionine) films for creatinine detection.

Creatinine (Ctn) is a biomarker for chronic kidney disease (CKD). In this study, a highly sensitive and specific detection method for Ctn based on a molecularly imprinted polymer (MIP) based electrochemical biosensor was developed. Mxene (Mx), which has high absorption properties, was modified using carbon screen-printed electrodes (SPCE). Subsequently, gold nanoparticles (AuNPs) were electrochemically deposited on the Mx/SPCE surface, followed by thionine as a redox-active functional monomer. Ctn served as a template molecule, resulting in poly(thionine) (PTH) on the AuNPs coated Mx surface (Mx@Au/PTH/MIP), providing the biosensor with high selectivity. The surface morphology, electrochemical measurements, and analytical performance of the developed Mx@Au/PTH/MIP nanozyme were evaluated using field-emission scanning electron microscopy, and other electroanalytical techniques. Nanozyme pact demonstrated high dynamic linear concentrations from 0.4 to 5000 μg/L with a detection limit of 0.03 μg/L and superior selectivity in the presence of possible interferences. To assist in accessible clinical analysis, a fabricated Mx@Au/PTH/MIP nanozyme exhibited outstanding consistency and high accessibility for sensing rat serum (adenine diet-induced kidney fibrosis model) samples without pretreatment. The developed biomimic nanozymes will not only assist in clinical analysis but also improve patient care.