A high sensitive long period fiber grating（LPFG） sensor for the detection of nitrite is proposed, which is realized by coating multiple poly（sodium 4-styrensulfonate）（PSS） and poly（diallyldimethylammonium） chl...A high sensitive long period fiber grating（LPFG） sensor for the detection of nitrite is proposed, which is realized by coating multiple poly（sodium 4-styrensulfonate）（PSS） and poly（diallyldimethylammonium） chloride （PDDA） layers on the fiber grating surface. The sensitivity of this LPFG sensor is maximum when the number of assembled layers is 70. Under this condition, a nitrite concentration of 3×10^-3 mol/L, which is lower than the National Food Additive Standard, 4.2×10^-3 mol/L, can be distinguished. The sensitivity is further increased by 30% when nitrite was determined in the sucrose solution with a concentration of 65%, which provides a new solution for the best refraction index approaching matched index of the fiber cladding. Compared with chemical methods, this nitrite detection technology offers some advantages, such as high accuracy, non toxicity, high speed, low cost, without chemical reagent, and is suitable for foodstuff security detection.展开更多
Gold nanoparticle(AuNPs)-decoratedα-Fe_(2)O_(3) nanorod arrays(AuNPs-Fe_(2)O_(3))were successfully fabricated by immersing hydrothermal-induced Fe_(2)O_(3) nanorod arrays into HAuCl4 solution,followed by a simple red...Gold nanoparticle(AuNPs)-decoratedα-Fe_(2)O_(3) nanorod arrays(AuNPs-Fe_(2)O_(3))were successfully fabricated by immersing hydrothermal-induced Fe_(2)O_(3) nanorod arrays into HAuCl4 solution,followed by a simple reduction process.The obtained AuNPs on theα-Fe_(2)O_(3) nanorods were about 3-5 nm in diameter.The photocurrent of AuNPs-Fe_(2)O_(3) was twice as large as that ofα-Fe_(2)O_(3) nanorods.Benefiting from the good photoelectric properties,the proposed AuNPs-Fe_(2)O_(3) can be directly utilized as a self-supporting photoelectrode for nitrite detection.As a result,the as-constructed sensor exhibited good photoelectron catalytic activity and selectivity,high sensitivity(0.1736±0.01μAμM^(-1) cm^(-2))and a low limit of detection(0.07μM).The current response has a high linear correlation(R≥0.999)in a wide range from 1μM to 1000μM and high stability.In addition,the as-constructed sensor was further employed for nitrite detection in tap and rain water samples to evaluate its practical applications.展开更多
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
Carbon fiber cloth(CC),by virtue of its flexible,conductive,and low-cost features,has generated great interest as the underlying backbone in many electrochemical reactions.Here,we report on our recent finding that CC ...Carbon fiber cloth(CC),by virtue of its flexible,conductive,and low-cost features,has generated great interest as the underlying backbone in many electrochemical reactions.Here,we report on our recent finding that CC could be directly employed as an anode for nitrite detection.It exhibited surprisingly high sensing performance toward nitrite with low determination and detection limit,high sensitivity,wide linear detection range,and excellent selectivity and stability,as well as good feasibility of testing nitrite in actual samples.Note that these parameters of CC are comparable or even superior to those of most of the reported carbon-,transition metal-,and noble metal-based advanced nitrite sensors.We also proved that the acid-oxidized CC with rougher surface and more carbon-oxygen functional groups exhibited higher current response and sensitivity toward nitrite.The advantages including superior sensing performance,low electrode cost,no requirement for additional synthetic or complex pretreatment processes,and commercial off-the-shelf nature enable CC to be an ideal electrochemical sensor for nitrite determination.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.60707016 and 60807030)
文摘A high sensitive long period fiber grating（LPFG） sensor for the detection of nitrite is proposed, which is realized by coating multiple poly（sodium 4-styrensulfonate）（PSS） and poly（diallyldimethylammonium） chloride （PDDA） layers on the fiber grating surface. The sensitivity of this LPFG sensor is maximum when the number of assembled layers is 70. Under this condition, a nitrite concentration of 3×10^-3 mol/L, which is lower than the National Food Additive Standard, 4.2×10^-3 mol/L, can be distinguished. The sensitivity is further increased by 30% when nitrite was determined in the sucrose solution with a concentration of 65%, which provides a new solution for the best refraction index approaching matched index of the fiber cladding. Compared with chemical methods, this nitrite detection technology offers some advantages, such as high accuracy, non toxicity, high speed, low cost, without chemical reagent, and is suitable for foodstuff security detection.
基金financially supported by the National Key R&D Program of China(2017YFA0207203)the CAS Pioneer Hundred Talents Program,and the CAS/SAFEA International Partnership Program for Creative Research Teams of Chinese Academy of Sciences,China.
文摘Gold nanoparticle(AuNPs)-decoratedα-Fe_(2)O_(3) nanorod arrays(AuNPs-Fe_(2)O_(3))were successfully fabricated by immersing hydrothermal-induced Fe_(2)O_(3) nanorod arrays into HAuCl4 solution,followed by a simple reduction process.The obtained AuNPs on theα-Fe_(2)O_(3) nanorods were about 3-5 nm in diameter.The photocurrent of AuNPs-Fe_(2)O_(3) was twice as large as that ofα-Fe_(2)O_(3) nanorods.Benefiting from the good photoelectric properties,the proposed AuNPs-Fe_(2)O_(3) can be directly utilized as a self-supporting photoelectrode for nitrite detection.As a result,the as-constructed sensor exhibited good photoelectron catalytic activity and selectivity,high sensitivity(0.1736±0.01μAμM^(-1) cm^(-2))and a low limit of detection(0.07μM).The current response has a high linear correlation(R≥0.999)in a wide range from 1μM to 1000μM and high stability.In addition,the as-constructed sensor was further employed for nitrite detection in tap and rain water samples to evaluate its practical applications.
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the National Natural Science Foundation of China(21675127)the Shaanxi Provincial Science Fund for Distinguished Young Scholars(2018JC-011)+2 种基金the Development Project of Qinghai Key Laboratory(2017-ZJ-Y10)the Capacity Building Project of Engineering Research Center of Qinghai Province(2017-GX-G03)This work was supported by Henan Key Laboratory of Cold Chain Food Quality and Safety Control.
文摘Carbon fiber cloth(CC),by virtue of its flexible,conductive,and low-cost features,has generated great interest as the underlying backbone in many electrochemical reactions.Here,we report on our recent finding that CC could be directly employed as an anode for nitrite detection.It exhibited surprisingly high sensing performance toward nitrite with low determination and detection limit,high sensitivity,wide linear detection range,and excellent selectivity and stability,as well as good feasibility of testing nitrite in actual samples.Note that these parameters of CC are comparable or even superior to those of most of the reported carbon-,transition metal-,and noble metal-based advanced nitrite sensors.We also proved that the acid-oxidized CC with rougher surface and more carbon-oxygen functional groups exhibited higher current response and sensitivity toward nitrite.The advantages including superior sensing performance,low electrode cost,no requirement for additional synthetic or complex pretreatment processes,and commercial off-the-shelf nature enable CC to be an ideal electrochemical sensor for nitrite determination.
