摘要
Single-atom nanozymes(SAzymes)are emerging as promising alternatives to mimic natural enzyme,which is due to high atomic utilization efficiency,well-defined geometric,and unique electronic structure.Herein,Fe single atoms supported on Ti_(3)C_(2)T_(x)(Fe-SA/Ti_(3)C_(2)T_(x))with intrinsic peroxidase activity is developed,further constructing a sensitive Raman sensor array for sensing of five antioxidants.Fe-SA/Ti_(3)C_(2)T_(x)shows excellent peroxidase-like performance in catalyzing the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)with colorimetric reactions.X-ray adsorption fine structure(XAFS)reveals that the electron transport between the Ti_(3)C_(2)T_(x)and Fe atoms occurs along Fe-O-Ti ligands,meanwhile the density functional theory(DFT)calculations confirm the spontaneous dissociation of H_(2)O_(2)and the formation of OH radicals.Furthermore,the peroxidase-like Fe-SA/Ti_(3)C_(2)T_(x)was used as surface enhanced Raman scattering(SERS)substrate of oxidized TMB(TMB+)and achieved satisfied signal amplification performance.Using the blocking effects of free radical reactions,one-off identification of 5 antioxidants,including ascorbic acid(AA),uric acid(UA),glutathione(GSH),melatonin(Mel),and tea polyphenols(TPP),could be realized with this high identifiable catalytic property.This principle could realize 100%distinguish accuracy combined with linear discriminant analysis(LDA)and heat map data analysis.A wide detection concentration ranges from 10^(-8)to 10^(-3)M for five antioxidants was also achieved.
基金
This work was supported by the National Natural Science Foundation of China(Nos.51872011,51902011,and 22005013)
Beijing Natural Science Foundation(No.2212018)
Beijing Institute of Technology Research Fund Program for Young Scholars(No.2022CX01011)
Chinese Academy of Sciences。