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Chemical Redox-Modulated Etching of Plasmonic Nanoparticles for nitrite Detection:Comparison Among Gold Nanosphere,Nanorod,and Nanotriangle

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Journal of Analysis and Testing 2021年第4期5卷 350-359页

作者： Zhiyu He Lan Zhang Guanhua Peng Guoqing Wang Xingguo Liang College of Food Science and Engineering Ocean University of ChinaQingdao 266003China Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology Qingdao 266237China

Colorimetric detection based on etching of plasmonic nanoparticles represents a relatively new strategy compared to that based on aggregation-based assay.It has been attracting research interest due to its advantages of rapidity,cost-eff ectiveness,and straightforward signaling.Boosted by the development of solution-phase synthesis,a range of shape-controlled plasmonic nanoparticles has emerged and been widely employed for colorimetric detection,including nanospheres,nanorods and nanotriangles.It has also been an opening question that which nanoparticle shapes should be chosen for a given analytical applications based on etching of plasmonic nanoparticles.This study demonstrated a colorimetric nitrite detection based on chemical etching of gold nanoparticles.Using nitrite-accelerated oxidation of iodide ion(I^(-)),the plasmonic nanoparticles are rapidly etched by the oxidation product iodine(I_(2)),leading to the formation of nanoparticles with etched morphology and shifted and plasmon resonance.Our results showed that gold nanosphere(AuNS)with large surface-area-to-volume(SAV)ratio and gold nanotriangle(AuNT)with sharp tips are highly active and aff ord fast etching in the presence of nitrite.The sensitivity of AuNS is higher than that of AuNT,and the detection limit is 4.5μM.Gold nanorod(AuNR)exhibits a comparable detection sensitivity to the AuNT because of similar aspect ratio and SAV ratio,but the slowest etching among the three types of nanoparticles.Given the high sensitivity and stability,the AuNSs are recommended for nitrite detection,and have been applied in the detection of drinking water.

关键词： Gold nanoparticles Etching nitrite Surface plasmon resonance

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Screening and Characterization of nitrite-Degrading Bacterial Isolates Using a Novel Culture Medium

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Journal of Ocean University of China 2020年第1期19卷 241-248页

作者： MA Qingshan HE Zengguo School of Medicine and Pharmacy Ocean University of ChinaQingdao 266003China Marine Biomedical Research Institute of Qingdao Qingdao 266003China

In this study,a novel culture medium that simulates shrimp pond conditions was established to screen nitrite-degrading isolates.The medium was supplemented with nitrite as a nitrogen source and shrimp feed as the major carbon source,to achieve the high nitrogen and low carbon nutritional status found in shrimp farming ponds.Screening using this medium identified potent denitrifying Bacillus isolates,among which Bacillus subtilis M7-1 was considered best.M7-1 was able to completely degrade nitrite-N in 24 h without much consumption of dissolved oxygen.Efficient denitrification activity took place in liquid cultures within a set of non-stringent ranges of pH(5.0–9.0),salinity(0–30)and temperature(25–35℃).The denitrifying enzyme gene was amplified,sequenced and further identified as nirS type.In biosecurity assessments,M7-1 had no negative effects on shrimps at a dose of 106 cfu mL−1.M7-1 could therefore be used in aquaculture to reduce and control the nitrogen concentration,and to promote the development of sustainable and healthy culture systems.

关键词： aerobic denitrification nitrite screening culture medium Bacillus subtilis

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Green-Emitting Carbon Dots as Fluorescent Probe for nitrite Detection

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Journal of Analysis and Testing 2021年第1期5卷 51-59页

作者： Mingcong Rong Danru Wang Yingyao Li Yazi Zhang Huiying Huang Rufeng Liu Xiangzhou Deng School of Chemistry and Chemical Engineering/Center for Advanced Analytical Science Guangzhou UniversityGuangzhou 510006China

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.

关键词： nitrite Carbon dots Sensing Diazotization reaction Fluorescence quenching

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Sequential injection spectrophotometric determination of nanomolar nitrite in seawater by on-line preconcentration with HLB cartridge

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Acta Oceanologica Sinica 2010年第1期29卷 100-107页

作者： ZHANG Min YUAN Dongxing HUANG Yongming CHEN Guohe ZHANG Zhen State Key Laboratory of Marine Environmental Science Enviromnental Science Research Center Xiamen University Xiamen 361005 China College of Life Science Shaoxing University Shaoxing 312000 China

The unstable state of nitrite results in its very low concentration in seawater, which is below the limit of detection （LOD） of conventional techniques of analysis. Some sensitivity-enhanced methods have been proposed for the determination of nitrite at nanomolar level to illustrate the role of nitrite in the marine nitrogen cycle. However, most of previous reports are not widely accepted, because of their complexity and cost equipment or intensive labor requirement. In this study, a simple automatic system for the determination of nanomolar level nitrite using on-line preconcentration with spectrophotometric detection was described..An Oasis HLB cartridge was adopted to quantitatively enrich the pink-colored azo compound, formed from nitrite via Griess reaction. The cartridge was rinsed with water and ethanol （volume fraction is 55%, the same below）, in turn, then eluted by an eluent containing 50% ethanol and 0.25 M（mol/dm^3） H2SO4, and determined at 543 nm with a 2 cm path-length flow cell. Under the optimized experimental conditions, the calibration curve showed a good linearity in the range of 1.4 85.7 aM, and the LOD （3a） was estimated to be 0.5 nM. The relative standard deviations of 7 measurements were 4.0% and 1.0% for the samples spiked at 7.1 and 28.6 nM, respectively. The recoveries for the different natural water samples were between 92.2%-108.4%. Each HLB cartridge could be reused for at least 50 times. As compared with other SPE methods, the advantages of this method included the free of interference from salinity variation and less sample consuming. The results of the application of the proposed method to natural water showed good agreement with liquid waveguide capillary cell detection method.

关键词： nitrite seawater on-line preconcentration sequential injection solid phase extraction

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Process Optimization and Modeling by Response Surface Methodology of nitrite Electro-Reduction by Ti/RuO₂ + IrO₂ Electrode

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American Journal of Analytical Chemistry 2023年第12期14卷 531-540页

作者： Mar Bassine Boye Abdou Khadre Djily Dimé Adama Diop Cheikhou Kane Modou Fall Département de Chimie UFR SATIC Equipe des Matériaux Electrochimie et Photochimie Analytiques (EMEPA) de l’Université Alioune Diop de Bambey Bambey Sénégal Laboratoire d’Electrochimie et de Procédés Membranaires (LEPM) Ecole Supérieure Polytechnique de Dakar Dakar Sénégal Laboratoire de Chimie Physique Organique et d’Analyses Environnementales Université Cheikh Anta Diop de Dakar Dakar Sénégal

Electrochemical reduction is one of the most suitable methods for the treatment of highly nitrate-contaminated solutions. This work focuses on the optimization of parameters influencing the electrochemical denitrification of water by the Ti/RuO2 + IrO2 electrode. The methodological approach used consists in carrying out a series of electrolysis by scrutinizing the reaction selectivity according to the experimental conditions. For this study, the ions concentrations before and after electrolysis were determined by UV-vis absorption spectroscopy. The results of the process optimization showed that the electrochemical reduction ofis efficient at neutral pH after 120 mn of electrolysis at -100 mA. In contrast to works found in the literature, this study highlighted the process modeling that could open interesting perspectives to develop new treatment methods of polluted waters.

关键词： Electrochemical Reduction Water Treatment nitrite Optimization Modelling

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A MnOOH-Polyaniline Nanocomposite Modified Gold Electrode for Electrochemical Sensing of nitrite

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Chinese Journal of Chemistry 2017年第8期35卷 1317-1321页

作者： Yu Shen Jian Zhang Qinglin Sheng Jianbin Zheng Institute of Analytical Science Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry Northwest University Xi'an Shaanxi 710069 China

A novel non-enzymatic nitrite sensor was fabricated by immobilizing MnOOH-PANI nanocomposites on a gold electrode （Au electrode）. The morphology and composition of the nanocomposites were investigated by transmission electron microscopy （TEM） and Fourier transform infrared spectrum （FTIR）. The electrochemical results showed that the sensor possessed excellent electrocatalytic ability for NO2 oxidation. The sensor displayed a linear range from 3.0 μmol·L^-1 to 76.0 mmol·L^-1 with a detection limit of 0.9 μmol·L^-1 （S/N=3）, a sensitivity of 132.2 μA·L·mol^-1·cm^-2 and a response time of 3 s. Furthermore, the sensor showed good reproducibility and long-term stability. It is expected that the MnOOH-PANI nanocomposites could be applied for more active sensors and used in practice for nitrite sensing.

关键词： electrochemical sensor nanocomposites polyaniline MnOOH nitrite

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Preparation and Characterization of Novel Choline and L-Glutamic Acid Mixed Monolayer Covalently Modified Glassy Carbon Electrode and Its Analytical Application to nitrite Determination

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Chinese Journal of Chemistry 2005年第6期23卷 673-677页

作者：晋冠平林祥钦 DepartmentofChemistry UniversityofScienceandTechnologyofChinaHefeiAnhui230026China

A choline and L ‐glutamic acid mixed monolayer covalently modified glassy carbon electrode (Ch‐Glu/GCE) was fabricated and characterized by X‐ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). It provided an excellent example of mixed covalent monolayer modification of carbon electrodes with alkanol and amino acid, and also a facile means for altering the interfacial architecture. The Ch‐Glu/GCE displayed good catalytic activity toward the oxidation of nitrite anions. Differential pulse voltammetry was used for determination of nitrite at the Ch‐Glu/GCE. The Ch‐Glu/GCE showed higher capability for restraint of pollutions than a simple Ch modified electrode or a simple Glu modified electrode.

关键词： monolayer mixed covalently modified electrode choline L‐glutamic acid nitrite

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An automated flow-batch analyzer based on spectrophotometry for the determination of nitrite

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Optoelectronics Letters 2019年第5期15卷 339-342页

作者：董辰杨李文湛王志宏曾俊翔梁晋涛 School of Life and Environmental Sciences Guilin University of Electronic Technology

An automated flow-batch analyzer(FBA) based on spectrophotometry was developed for the determination of nitrite(NO2-) in environmental waters. The FBA consists of a homemade flow cell, light source, detector and a mini-syringe pump, which was controlled by self-designed software written in Lab VIEW. Two LEDs and a light-to-voltage converter were used as the light source and detector respectively. The chemical detection method was based on spectrophotometry and modified Griess reaction. With the optimized conditions, the limit of detection(LOD) was 0.018 μmol·L^-1 and the relative standard deviations(RSDs) at different concentrations(0-12 μmol·L^-1) were 0.54%-3.63%(n=3). Measurements of different aqueous samples(n=21) showed no significant difference between results obtained by developed FBA and a commercial spectrophotometer.

关键词： determination nitrite flow-batch analyzer(FBA)

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Selection of nitrite-degrading and biogenic amine-degrading strains and its involved genes

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Food Quality and Safety 2020年第4期4卷 225-235页

作者： Yuxin Li Zhihui Yu Yingchun Zhu Zhixiang Cao College of Food Science and Engineering Shanxi Agricultural UniversityShanxiChina College of Food Science and Technology Hebei Agricultural UniversityHebeiChina

Objectives:Accumulation of nitrite and biogenic amines(BAs)in fermented meat products is a matter of public health concern.The study aimed to screen nitrite-degrading and BA-degrading strains from sour porridges and sausages and bacon products in China.Materials and Methods:After screening out 12 strains,the degradation of nitrite,the degradation of BAs,the activities of nitrite-reducing enzymes,and the detection of genes involved in the BAs were assessed by spectrophotometry method with hydrochloric acid naphthalene ethylenediamine,high-performance liquid chromatography,GENMED kit,and polymerase chain reaction,respectively.Results:Pediococcus pentosaceus labelled M SZ12 and M GC 2,Lactobacillus plantarum labelled M SZ22,and Staphylococcus xylosus labelled Y CC 3 were selected.The activity of nitrite-reducing enzyme in M SZ22 was 2.663 units/mg.The degradation rate of total BAs of M SZ22 was 93.24%.The degradation rates of nitrite and BAs of M SZ12 were 86.49%and 37.87%,respectively.The activity of nitrite-reducing enzyme in M SZ12 was up to 1.962 units/mg.M GC 2 showed higher degradation rates of nitrite(89.19%)and Y CC 3 showed higher degradation rates of BAs(36.16%).The genes encoding the multicopper oxidases(suf I/D2EK17)were detected in the four strains,which also did not contain BAs(histidine decarboxylase(hdc),tyrosine decarboxylase(tdc),ornithine decarboxylase(odc),lysine decarboxylase(ldc))formation encoding genes.Conclusion:These four strains(M SZ12,M GC 2,M SZ22,and Y CC 3)are promising candidates to use as starter cultures for nitrite and BAs in fermented sausages.

关键词： nitrite biogenic amines degradation rate strains genetic testing

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Study on Changes of nitrite Content in Two Kinds of Foods under Different Storage Conditions

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Agricultural Biotechnology 2023年第4期12卷 41-44页

作者： Xiulan WU Feitong ZHUO School of Food and Pharmaceutical Engineering Zhaoqing UniversityZhaoqing 526061China

[Objectives]This study was conducted to store and consume overnight vegetables more safely and reasonably.[Methods]Fried cabbage and barbecue was selected as raw materials,which were determine by Griess reagent colorimetry for the effects of storage time,storage temperature and storage method on the changes in nitrite content in the two foods.[Results]The nitrite content in fried cabbage and barbecue increased with the prolongation of storage time.Both types of food,whether stored in a sealed or open manner,had a nitrite content that increased with the storage temperature.When barbecue was stored in an open manner,its nitrite content was greater than that in sealed storage.The condition of stir-fried cabbage was the same as barbecue when stored at 10℃,but the situation was opposite when stored at 20 and 30℃.In this study,except for the slightly excessive nitrite content in stir-fried cabbage stored at 30℃in open and sealed conditions for 72 h,the nitrite contents in both foods under other storage conditions all met the national standard limit.[Conclusions]This study provides a theoretical basis for the safe and reasonable storage and use of leftovers.

关键词： nitrite Storage Stir-fried cabbage Barbecue

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