Nitrite(NO_(2)_(-))is a well-known inorganic pollutant in food and environment that can trigger severe environmental and healthy problems.Consequently,establishing accurate NO_(2)_(-)detection method is very important...Nitrite(NO_(2)_(-))is a well-known inorganic pollutant in food and environment that can trigger severe environmental and healthy problems.Consequently,establishing accurate NO_(2)_(-)detection method is very important for food security,environment monitoring and human health.In this work,green fluorescent carbon dots(CDs)with a high fluorescence quantum yield(QY)of 36.13%are prepared for NO_(2)_(-)detection.The CDs are prepared by one-pot hydrothermal carbonization and polymerization of acriflavine.After carbonization,the anti-photobleaching property of CDs significantly enhanced compared to acriflavine.Under acidic conditions,the added of NO_(2)_(-)selectively induces the aggregation and fluorescence quenching of CDs.A good fluorescence linearity response in the range of 50 nM to 10μM can be developed for NO_(2)_(-)quantitative analysis,with a detection limit of 11.6 nM.Owing to the diazotization reaction of NO_(2)_(-)and the phenylamine groups on the surface of CDs,this method shows excellent selectivity compared to common ions and amino acids.Furthermore,the proposed method shows favorable results in the detection of real water and Cantonese style sausage sample.This study provides a simple and e fficient method for NO_(2)_(-)detection in food and environment.展开更多
基金the support from National Youth Foundation of China(No.21904027)the Natural Science Foundation of Guangdong Province(2019A1515011328)Featured Innovation Project of Guangdong Province O ffice of Education(2018KTSCX180)
文摘Nitrite(NO_(2)_(-))is a well-known inorganic pollutant in food and environment that can trigger severe environmental and healthy problems.Consequently,establishing accurate NO_(2)_(-)detection method is very important for food security,environment monitoring and human health.In this work,green fluorescent carbon dots(CDs)with a high fluorescence quantum yield(QY)of 36.13%are prepared for NO_(2)_(-)detection.The CDs are prepared by one-pot hydrothermal carbonization and polymerization of acriflavine.After carbonization,the anti-photobleaching property of CDs significantly enhanced compared to acriflavine.Under acidic conditions,the added of NO_(2)_(-)selectively induces the aggregation and fluorescence quenching of CDs.A good fluorescence linearity response in the range of 50 nM to 10μM can be developed for NO_(2)_(-)quantitative analysis,with a detection limit of 11.6 nM.Owing to the diazotization reaction of NO_(2)_(-)and the phenylamine groups on the surface of CDs,this method shows excellent selectivity compared to common ions and amino acids.Furthermore,the proposed method shows favorable results in the detection of real water and Cantonese style sausage sample.This study provides a simple and e fficient method for NO_(2)_(-)detection in food and environment.
文摘作者对对肼基苯磺酸合成路线进行了优化。以对氨基苯磺酸为原料,经过重氮化反应和还原反应,一锅法合成对肼基苯磺酸。选取碱种类、浓盐酸的用量、反应温度3个因素,利用正交实验对反应进行优化,得到最佳反应条件为2 g对氨基苯磺酸用11.5 mL 5%氢氧化钠溶液溶解,再用8.0 mL浓盐酸进行重氮化,之后再还原反应即可得产品,平均收率为75.0%。对优化后的工艺进行中试放大试验,反应条件温和,操作简便,收率稳定,具有一定的工业化应用前景。
