Food safety problems caused by excessive nitrite addition have been frequently reported and the detection of nitrite in food is particularly important. The standing time during the pretreatment of primary sample has a...Food safety problems caused by excessive nitrite addition have been frequently reported and the detection of nitrite in food is particularly important. The standing time during the pretreatment of primary sample has a great influence on the concentration of nitrite tested by spectrophotometric method. In this context, three kinds of food samples are prepared, including canned mustard, canned fish and home-made pickled water. A series of standing times are placed during the sample pretreatments and the corresponding nitrite contents in these samples are detected by spectrophotometric method based on N-ethylenediamine dihydrochloride. This study aims to find out a reasonable standing time during the pretreatment of food sample, providing influence factor for precise detection of nitrite.展开更多
Long-term excessive intake of nitrite(NO_(2)^(-))poses a great threat to human health,needing a simple and fast method to detect NO_(2)-in food.Herein,via a simple and feasible strategy,Mn/Yb/Er triple-doped CeO_(2) n...Long-term excessive intake of nitrite(NO_(2)^(-))poses a great threat to human health,needing a simple and fast method to detect NO_(2)-in food.Herein,via a simple and feasible strategy,Mn/Yb/Er triple-doped CeO_(2) nanozyme(Mn/Yb/Er/CeO_(2))was synthesized for highly sensitive ratiometric detection of nitrite.By doping Mn,Yb,Er into CeO_(2) lattice structure,Mn/Yb/Er/CeO_(2) nanozyme showed enhanced oxidase-like activity,obtaining a higher density of oxygen vacancy and a higher ratio of Ce^(3+)to Ce~(4+)than that of CeO_(2).The 3,3,5,5-tetramethylbenzidine(TMB)can be effectively oxidized by Mn/Yb/Er/CeO_(2) to produce the oxidized TMB(ox TMB),showing a significant absorption signal at 652 nm.Additionally,nitrite can react with ox TMB to produce yellow diazotized ox TMB,which is accompanied by an elevated absorption signal at 445 nm and a decreased absorption signal at 652 nm.Thus,based on the oxidase-mimetic activity of Mn/Yb/Er/CeO_(2) and the diazotization reaction between NO_(2)^(-)and ox TMB,a ratiometric colorimetric assay was established for NO_(2)^(-)detection in food.Furthermore,by integrating Mn/Yb/Er/CeO_(2) with a smartphone,a colorimetric smartphone-sensing platform was successfully fabricated for visualization and quantitative detection of NO_(2)^(-).Notably,this two-detection mode showed excellent sensitivity,selectivity,reliability and practicability in monitoring the NO_(2)^(-)in real samples,impling its great potential for food safety.展开更多
文摘Food safety problems caused by excessive nitrite addition have been frequently reported and the detection of nitrite in food is particularly important. The standing time during the pretreatment of primary sample has a great influence on the concentration of nitrite tested by spectrophotometric method. In this context, three kinds of food samples are prepared, including canned mustard, canned fish and home-made pickled water. A series of standing times are placed during the sample pretreatments and the corresponding nitrite contents in these samples are detected by spectrophotometric method based on N-ethylenediamine dihydrochloride. This study aims to find out a reasonable standing time during the pretreatment of food sample, providing influence factor for precise detection of nitrite.
基金supported by the National Natural Science Foundation of China(Nos.22004111 and 21974125)the Tackle Key Problems in Science and Technology Project of Henan Province,China(No.222102310386)+3 种基金China Postdoctoral Science Foundation(No.2020M682327)Henan Postdoctoral Foundation(No.202002009)Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.22TRTSTHN002)Excellent Youth Foundation of Henan Scientific Committee(No.232300421021)。
文摘Long-term excessive intake of nitrite(NO_(2)^(-))poses a great threat to human health,needing a simple and fast method to detect NO_(2)-in food.Herein,via a simple and feasible strategy,Mn/Yb/Er triple-doped CeO_(2) nanozyme(Mn/Yb/Er/CeO_(2))was synthesized for highly sensitive ratiometric detection of nitrite.By doping Mn,Yb,Er into CeO_(2) lattice structure,Mn/Yb/Er/CeO_(2) nanozyme showed enhanced oxidase-like activity,obtaining a higher density of oxygen vacancy and a higher ratio of Ce^(3+)to Ce~(4+)than that of CeO_(2).The 3,3,5,5-tetramethylbenzidine(TMB)can be effectively oxidized by Mn/Yb/Er/CeO_(2) to produce the oxidized TMB(ox TMB),showing a significant absorption signal at 652 nm.Additionally,nitrite can react with ox TMB to produce yellow diazotized ox TMB,which is accompanied by an elevated absorption signal at 445 nm and a decreased absorption signal at 652 nm.Thus,based on the oxidase-mimetic activity of Mn/Yb/Er/CeO_(2) and the diazotization reaction between NO_(2)^(-)and ox TMB,a ratiometric colorimetric assay was established for NO_(2)^(-)detection in food.Furthermore,by integrating Mn/Yb/Er/CeO_(2) with a smartphone,a colorimetric smartphone-sensing platform was successfully fabricated for visualization and quantitative detection of NO_(2)^(-).Notably,this two-detection mode showed excellent sensitivity,selectivity,reliability and practicability in monitoring the NO_(2)^(-)in real samples,impling its great potential for food safety.
