Abstract
Long-term excessive intake of nitrite(NO2-)poses a great threat to human health,needing a simple and fast method to detect NO2-in food.Herein,via a simple and feasible strategy,Mn/Yb/Er triple-doped CeO2 nanozyme(Mn/Yb/Er/CeO2)was synthesized for highly sensitive ratiometric detection of nitrite.By doping Mn,Yb,Er into CeO2 lattice structure,Mn/Yb/Er/CeO2 nanozyme showed enhanced oxidase-like activity,obtaining a higher density of oxygen vacancy and a higher ratio of Ce3+to Ce4+than that of CeO2.The 3,3',5,5'-tetramethylbenzidine(TMB)can be effectively oxidized by Mn/Yb/Er/CeO2 to produce the oxidized TMB(oxTMB),showing a significant absorption signal at 652 nm.Additionally,nitrite can react with oxTMB to produce yellow diazotized oxTMB,which is accompanied by an elevated absorp-tion signal at 445 nm and a decreased absorption signal at 652 nm.Thus,based on the oxidase-mimetic activity of Mn/Yb/Er/CeO2 and the diazotization reaction between NO2-and oxTMB,a ratiometric col-orimetric assay was established for NO2-detection in food.Furthermore,by integrating Mn/Yb/Er/CeO2 with a smartphone,a colorimetric smartphone-sensing platform was successfully fabricated for visualiza-tion and quantitative detection of NO2-.Notably,this two-detection mode showed excellent sensitivity,selectivity,reliability and practicability in monitoring the NO2-in real samples,impling its great potential for food safety.
基金项目
National Natural Science Foundation of China(22004111)
National Natural Science Foundation of China(21974125)
Tackle Key Problems in Science and Technology Project of Henan Province,China(222102310386)
China Postdoctoral Science Foundation(2020M682327)
Henan Postdoctoral Foundation(202002009)
Program for Innovative Research Team(in Science and Technology)in University of Henan Province(22TRTSTHN002)
Excellent Youth Foundation of Henan Scientific Committee(232300421021)
NETL
NSTL
万方数据