Detection Of Nitrite Research Articles

Branched CuAu nano-alloy for N2H4 oxidation-assisted H2 production and nitrite detection in water solution.

The H2 production using N2H4 splitting (OHzS) was often constrained by the requirement for insufficient stability, distinct catalysts at the anode and cathode, and the high-cost electrocatalyst associated with confined activity. This work verified the efficacy of surfactant-free branched CuAu nano-alloy as a bifunctional electrocatalyst for H2 production. Benefiting from its favorable electronic structure and surfactant-free surface, surfactant-free CuAu nano-alloy demonstrated a reduced over-potential compared withpure Cu, pure Au, and CuAu nano-alloy prepared by surfactant. When using branched CuAu nano-alloy as both cathodic and anodic electrodes, a cell voltage of 0.768V was required to drive a current density of 10mA/cm2. After 2550min of H2 generation, the amplitude of the working potential for anodic reactions was found to be less than 0.92%. The enhanced electrocatalytic activity could be also applied to H2O2 and NaNO2 sensors. The CuAu nano-alloy exhibited a 2.35-folds increase in sensitivity compared to pure Au nano-crystals in the detection of H2O2. Moreover, the detection of NaNO2 in water solution has been successfully achieved. The detection range 0-175.0mM was much wider than that ofsensors in previous works.

Simple strategy for dual-responsive ratio electrochemical-colorimetric detection of nitrite in food and environment.

A dual-responsive ratio electrochemical-colorimetric method for nitrite (NO2-) is established based on the combination of nanoenzyme (Mn3O4) catalysis with diazotization reactions. The Mn3O4 can oxidize colorless 3,3',5,5'-tetramethylbenzidine (TMB) into blue TMBox. The NO2- induces the diazotization reaction of TMBox, leading to a decrease of the signal at 652nm and the generation of a new signal from diazotized TMBox at 445nm. Furthermore, the presence of NO2- reduces the electrochemical oxidation signal of TMB and simultaneously provides its electrochemical signal. Compared withtraditional single-mode detection, dual-mode detection offers higher sensitivity, lower detection limits, and better interference resistance. The inherent advantages of this method make it feasible to detect NO2- in real samples, offering broad prospects for applications in food safety and environmental monitoring.

Ultrabright silicon nanoparticles combined with o-phenylenediamine for ratiometric fluorescence and smartphone imaging dual-mode detection of nitrite

Nitrite (NO2−) is widely present in the natural environment and human daily life. Excessive NO2− can cause harm to the environment and human health. Herein, silicon nanoparticles (SiNPs) with a fluorescence quantum yield of up to 70 % were synthesised using a one-pot hydrothermal method and combined with the common and inexpensive o-phenylenediamine (OPD) to achieve the detection of NO2−. Upon the addition of NO2−, the blue fluorescence of the SiNPs was quenched due to static quenching and Förster resonance energy transfer (FRET), while the yellow fluorescence of benzotriazole, the reaction product of OPD and NO2−, was enhanced, resulting in the fluorescence color change from blue to yellow. Based on these phenomena, a ratiometric fluorescence sensor integrated with smartphone imaging technology was developed. This sensor is notable for its portability, cost-effectiveness, and satisfactory detection limits (0.016 μM for ratiometric fluorescence and 1.64 μM for smartphone imaging). Importantly, it demonstrates high reliability and practicability in detecting NO2− in real water and food samples. This broadens the application of SiNPs in the sensing field and introduces new possibilities for NO2− detection in complex sample matrices.

Nano-sized gold particles driven interfacial reaction for the enhanced electrochemical nitrite sensing

Nitrite is a typical food additive and chemical fertilizer, which could pose toxicity to human and aquatic organisms when it is excessive. Therefore, it is meaningful to develop reliable analytical methods for nitrite detection. In this work, an innovative electrochemical nitrite sensor has been fabricated using In2O3 decorated with high-activity nano-sized Au particles (Au/In2O3), which were synthesized through a two-step synthetic method combining hydrothermal reaction and deposition-precipitation, resulting in an excellent sensing performance for the nitrite. Specifically, the electrochemical nitrite sensor based on Au/In2O3 exhibits high sensitivity with a linear detection range from 10 μM to 5 mM at pH 7.38. Additionally, the Au/In2O3 based nitrite sensor shows a detection limit of 0.46 μM and presents impressive selectivity and stability. The extraordinary nitrite sensing performance can be attributed to the excellent catalytic activity of nano-sized Au particles and the strong interfacial reaction between Au/In2O3 and nitrite. Furthermore, theoretical calculations reveal the interfacial reactions mechanism driven by Au particles, which enhance the charge transfer between Au/In2O3 and nitrite and thus improve its electrochemical sensing performance. This work presents a novel approach towards fabricating high-performance electrochemical nitrite sensor and reveals the enhanced interfacial reaction mechanism of nano-sized Au particles.

A novel electrochemical sensor for ultra-sensitive detection of nitrite based on the synergistic effect of surfactant and KTiTaO5

A novel electrochemical sensor for ultra-sensitive detection of nitrite based on the synergistic effect of surfactant and KTiTaO5

A novel poly(Rhodamine B) coated polylactic acid doped carbon black electrode for nitrite detection in drinking water

A novel poly(Rhodamine B) coated polylactic acid doped carbon black electrode for nitrite detection in drinking water

Nitrite: From Application to Detection and Development

Nitrite, a collective term for a group of inorganic compounds containing nitrite ions (NO2−), is widely present in the natural environment and in the human body. It has a wide range of applications in the medical, food and environmental fields, such as food additives, water treatment agents and drugs. However, the excessive intake of nitrite poses indirect carcinogenic, teratogenic and mutagenic risks to humans. With the in-depth study of the functional properties of nitrite, there is an increasing demand for accurate and efficient methods for its detection. This paper presents a review of methods for the detection of nitrite, which will cover different principles and technologies, including traditional methods, optical methods, electrochemical sensors, and biosensors, and their prospects. By comparing and evaluating the different methods, it will provide references and valuable suggestions for choosing the most suitable nitrite detection methods and the scientific selection of alternatives for nitrite.

Fast preparing bioelectrode with conductive bioink for nitrite detection in high sensitivity and stability

Electrochemically active biofilms (EABs) for nitrite detection have high specificity, rapid response, operational simplicity, and extended lifespan advantages. However, their scale production remains challenging due to time-consuming and uniform preparation. In this study, a novel approach was proposed to fast fabricate an EAB biosensor with a synthetic biofilm electrode for nitrite detection. The biofilm electrode was prepared by coating bioinks with varying conductive materials onto the surface of the graphite sheets, showing short incubation time and good reproducibility. Incorporating conductive materials into the bioinks remarkably enhanced the maximum voltage of the first cycle of bioelectrode incubation, with an increase of up to 633% for carbon nanofibers. The nitrite reduction current was amplified by a factor of 2.97, due to the enhancement of extracellular electron transfer (EET). The developed nitrite biosensor exhibited a detection range of 0.1–15 mg NO2--N L−1, with a high sensitivity of 610.8 μA mM−1 cm−2, and a stabilization operation time of at least 280 cycles. This study not only provided valuable insights into conductive materials for synthetic biofilms but also presented a practical approach for the rapid preparation, scale production, and optimization of highly sensitive and stable EAB sensors.

Fe/Cl/N triply-doped bamboo-like structure wrapped with Fe3C nanoparticles for electrochemical selective nitrite detection

Nitrite is commonly found in the natural environment and in everyday human activities. However, excessive nitrite consumption can potentially harm human health. Consequently, it is crucial to develop a reliable and sensitive method for nitrite detection. In this work, trichloroacetic acid functionalized Cl-Fe-MIL-88B metal-organic framework is obtained through nucleophilic reaction between animated Fe-MIL-88B and trichloroacetic acid, which is then annealed with melamine in an N2 atmosphere to produce the Fe/Cl/N triply-doped bamboo-like carbon nanotubes (CNTs) wrapped with Fe3C nanoparticles. Owing to the effective doping of Fe/Cl/N elements, the charge distribution and chemical activity of the bamboo-like structure are tailored, greatly improving the conductivity and facilitating electron transfer of the composite for potential electrocatalytic reaction. The Fe3C nanoparticles wrapped inside the CNTs contribute to expose more active sites and provide effective surface area. Accordingly, the Fe/Cl/N doped bamboo-like structure modified glassy carbon electrode shows excellent electrochemical nitrite sensing properties with a high sensitivity of 1060µAcm-2 mM-1, a low detection limit of 0.61µM in a wide linear concentration range of 5-5000μM, as well as good anti-interference and long-term stability. Also, the electrochemical sensor has a satisfactory recovery rate for detecting nitrite ions in spiked milk samples. This work proposes a simple precursor chlorination and pyrolysis strategy to obtain metal-filled bamboo-like structure with high electrical conductivity and electrocatalytic properties, endowing great potential in food safety and environment monitoring.

Rapid and selective quantitative colourimetric analysis of nitrite in water using a S-Nitrosothiol based method

This study introduces a novel S-nitrosothiol based method for the rapid and highly selective detection of nitrite in complex water matrices. Sodium 3-mercapto-1-propanesulfonate forms a distinctive pink S-nitrosothiol compound upon interaction with nitrite in acidic media, allowing both visual and quantitative detection. Various factors affecting the absorbance of the final product were investigated, including pH, reaction time, acid type, and sodium 3-mercapto-1-propanesulfonate concentration. UV–Vis spectrophotometric analysis demonstrated an excellent linear correlation (R2 = 0.99) across a broad detection range (0.05 to 80 mmol l-1), while showing no interference from common ions such as nitrate or dissolved organic matter, a limitation frequently observed in conventional UV-based nitrite detection methods. The assay was further adapted into a pellet form to simplify field use, operating effectively at room temperature with a low detection limit (1.4 ppm). The S-nitrosothiol based method represents a safer and more environmentally friendly option for nitrite detection and shows a promising potential as a valuable addition to both field and laboratory water testing kits for nitrite analysis.

Uniform nickel nanoparticles decorated porous carbon nanofibers for efficient electrochemical nitrite sensing

One-dimensional carbonaceous materials exhibit significant promise for sensing applications driven by their attractive properties. Herein, nickel/nitrogen-doped carbon (Ni/N–C) nanofibers were fabricated via a novel electrospinning-carbonization strategy. The distribution of Ni nanoparticles (NPs) in the carbon nanofibers was crucially affected by the carbonization temperatures. Various techniques were employed to characterize the fabricated Ni/N–C-X (X = 700, 800, and 900 °C, representing the carbonization temperatures) nanofibers, followed by an evaluation of their electrochemical sensing response to nitrite. The Ni/N–C-800-based sensor outperformed those based on the Ni/N–C-700 and Ni/N–C-900 catalysts in detecting nitrite, by merits of the relatively superior conductivity and more exposed active sites. The Ni/N–C-800-based sensor, delivered detected concentrations of 0.2–7000 μM, along with a sensitivity value of 0.991 μA μM−1 cm−2, and a detection limit of 0.1 μM. Furthermore, this Ni/N–C-800-based sensor demonstrated notable selectivity and stability, affirming its practicality in nitrite detection within sausage samples. The findings of this research illustrate that Ni/N–C materials hold great promise for monitoring nitrite.

Efficient sensitive detection of nitrite with Binary Y/Fe-modified multiwalled carbon nanotube nanocomposite by electrochemical approaches

Low-dimensional metal nanoparticles (MNPs) intercalated with three-dimensional multiwalled carbon nanotube (MWCNT) materials may be combined to produce new nanocomposites for enhancing their chemical, structural, and morphological features. These composites have interesting physical and chemical characteristics that can be used in electrochemical sensing systems that work significantly well. This research presents a new method for detecting nitrite using an electrochemical sensor that utilizes a flat-electrode made of GCE fabricated by nanocomposite of MWCNTs intercalated with yttrium oxide (Y2O3) and iron oxide (Fe2O3) as Y/Fe-MWCNT at higher temperature. FT-IR, UV–vis., SEM, powder XRD, EDS, BET, and TEM were significantly used to characterize in detail the nanocomposite after its preparation by the solid-state chemical approach. Using CV, LSV, and EIS techniques, the electrochemical attributes of both the bare and Y/Fe-MWCNT fabricated electrodes (with the help of 5 % Nafion as conducting coating binder) were investigated. In addition, the linear relationship between nitrite concentration and peak current of LSV was seen between 1.0 and 1.6 M, with a lower limit of detection (LOD) of 0.027 M. When compared to modified electrodes with nitrite, the electrocatalytic behavior of the nanocomposite electrode is enhanced significantly. At applied potential window of −0.1 to +1.8 V, the Y/Fe-MWCNT sensor shows good selectivity even when there are a lot of interfering chemicals and metal ions. In addition, different PBS electrolyte solutions with pH values ranging from 6.5 to 8 were used to study the prepared sensor. The standard addition method was employed to detect the unidentified nitrite concentration in various real samples including sea water, industrial wastewater, and well water. It introduced a new route for the development of noble sensor probe with nanocomposite materials by electrochemical approach for the safety of environmental and health care field in a broad scale.

Rational design of carbon dot nanozymes for ratiometric dual-signal and smartphone-assisted visual detection of nitrite in food matrices

Developing reliable nitrite (NO2−) sensors is essential for food safety and reducing health risks from NO2− exposure. In this study, we strategically designed nitrogen-doped carbon dot (N-CD) nanozymes to establish an accessible dual-signal ratiometric sensing system for detecting NO2− in food matrices. This system utilizes the photoluminescence and enzyme-like properties of N-CD nanozymes combined with NO2−-triggered diazotization reactions of substrates such as o-phenylenediamine (OPD) or 3,3',5,5'-tetramethylbenzidine (TMB). The resulting N-CD/OPD and N-CD/TMB composites provide dual-mode detection—fluorescence and colorimetric—with high selectivity for NO2− and excellent resistance to interference. These sensors exhibit clear color changes under both ultraviolet and visible light, and can be combined with smartphones for visual, on-site detection of NO2−. By incorporating a ratiometric strategy, dual-signal output, and smartphone compatibility, our system achieved a low detection limit (≤ 1.92μM) and satisfactory recovery rates (85.6~115%) in environmental water and food samples. This highlights the potential of smartphone-assisted sensors for environmental monitoring and food safety applications. Our carbon dot-based platform offers a practical and effective solution for on-site NO2− detection, contributing valuable insights to the field.

Swift and Cost-Effective Detection of Nitrite in Environmental Samples Using Ru@Pt Modified PGE

The development of a straightforward method is crucial for detecting and quantifying nitrite ions within the surrounding environment. This study involves the electrochemical fabrication of a bi-metallic alloy composed of Ruthenium and Platinum on a graphene-modified pge, the first-ever electrodeposition on pencil graphite (RuNPs@PtNPs/Gr-CHI). This study aims to establish a highly responsive and specific approach for identifying nitrite ions while demonstrating the efficacy of a commercially available pencil graphite electrode in detecting this environmental contaminant. The prevalence and structural characteristics of bimetallic nanoalloy particles are confirmed through X-ray diffraction, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The composite exhibited a core–shell shape at a size of 26.998 nm. The electrooxidation of nitrite at RuNPs@PtNPs/Gr-CHI/PGE was investigated using differential pulse voltammetry. The results demonstrated a satisfactory linear relationship from 0.025 mM to 1.625 mM. The method revealed a low detection limit of 0.33 μM. The composite electrode exhibited favorable outcomes regarding selectivity, sensitivity (25.5 μAμM−1cm−2), and repeatability, which are desirable characteristics of the electrochemical sensor material. The constructed electrode underwent testing for five weeks to determine the stability. The suggested sensor’s capability is demonstrated by detecting nitrite ions in real samples such as water, soil, and fruit juice.

Sensitive detection of unsafe nitrite chemical based on GO@Fe2O3/Y2O3 nanocomposite by electrochemical approach for environmental assessment

In this study, we quantified nitrite in phosphate buffer solution (PBS) at a pH of 8.00 using linear sweep voltammetry (LSV) under room conditions. The working electrodes (WE) were flat glassy carbon electrodes (GCEs) modified with a nanocomposite of graphene oxide, iron oxide, and yttrium oxide (GO@Fe2O3/Y2O3 NCs), fabricated using a 5 % Nafion conducting coating binder. The GO@Fe2O3/Y2O3 NCs were prepared by a solid-state chemical process and thoroughly analyzed using various techniques, including XRD, FTIR, FESEM, EDS, BET, HRTEM, EIS, and XPS, to examine their binding energy, surface area, crystallinity, structural integrity, functionality, and morphology. Electrochemical characteristics and detection capabilities of the modified electrodes were examined using cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). The linear dynamic range (LDR) for nitrite detection, determined using LSV, was from 0.74 to 1.09 M. The sensor exhibited a sensitivity of 73.83966 µAmM−1cm−2, calculated from the slope of the calibration curve considering the electrode’s surface area. The lower limit of detection (LOD) was found to be 2.25 mM, and the limit of quantification (LOQ) was 7.50 mM. Additionally, we thoroughly investigated pH optimization, sensor-probe characteristics, stability, and reliability of the sensor under the same conditions. Validity tests conducted on the GO@Fe2O3/Y2O3 NCs/Nafion/GCE sensor probe demonstrated reliable and accurate performance in spike samples. This novel electrochemical sensor method shows promise for large-scale environmental chemical monitoring, aiming to enhance safety in environmental and healthcare sectors.

Electrochemical sensors for sensitive and selective detection of nitrite based on flexible gold microneedle like nanodendrites modified electrode

In this study, we present a new approach utilizing Au nanodendrites (Au NDs) to modify flexible screen-printed carbon electrodes (FSPCEs), offering an efficient platform for voltammetric sensing of nitrite ions in food samples. The FSPCEs are created with gold leaf-like nanodendrites through a simple, one-step electrochemical deposition process. The direct growth of these Au NDs occurs efficiently on the carbon-paste electrode, eliminating the need for binders or additional reducing agents and organic solvents, owing to the aforementioned matrix. The modified electrodes serve as promising sensing platforms for nitrite detection. The outcomes demonstrated that a significant amount of AuNPs with dendritic morphologies were dispersed throughout the FSPCE.These novel flexible electrodes act as effective electrocatalyst for NO2− oxidation due to their large electrochemical active surface area (ECSA), well-dispersed Au nanostructures, and high electrical conductivity. The optimized sensor exhibits a wide linear response range from 0.02 to 5.8 µM, with 1.0 nM limit of detection, an impressive sensitivity of 52.529 µA µM−1 cm−2 and a quick current response time (< 3 s) towards nitrite ions. Additionally, the suggested sensor demonstrates high selectivity, reproducibility, and stability. Furthermore, the FSPCEs are evaluated for their ability to selectively detect nitrite ions in various food samples such as tap water, drinking water, milk, and fruit juices, comparing the results with standard methods in real sample analysis. The fabricated sensors show promising potential for practical applications in food and environmental analysis. Consequently, Au NDs@FSPCE electrode emerged to be a novel platform for NO2− electrochemical detection. Because of their great affinity for analytical substances in solutions, gold nanodendrites supported on flexible screen-printed carbon electrodes (FSPCEs) are very useful for electrode modifications. Their increased effective surface area, which greatly raises the electrode's sensitivity and specificity for a range of analytical applications, is responsible for their high affinity.

Green Synthesis of Cobalt Oxide Decorated Chitosan Substrates for Electrochemical Detection of Nitrite and Hydrogen Evolution Reactions

Green Synthesis of Cobalt Oxide Decorated Chitosan Substrates for Electrochemical Detection of Nitrite and Hydrogen Evolution Reactions

N-doped antioxidant carbon dots as a bimodal probe for nitrite detection in commercial meat products

Accurate, sensitive, and specific nitrite ion (NO2−) detection is critical for maintaining the quality of food and water, given its ubiquitous presence in the environment. This investigation introduces the development of nitrogen-infused carbon dots, which serve dual functions as antioxidants and NO2−sensors in food products. These carbon dots (CDs) facilitates bimodal NO2− detection, combining precise fluorimetric detection and straightforward colorimetric analysis. Upon introduction into the solution, NO2− interacts with the amino groups on the surface of the CDs, resulting in the formation of a diazotized compound and causing a color change in the solution. Notably, the detection limits for NO2− are determined to be 0.19 μM and 0.144 μM, respectively. In addition, the bimode probe demonstrates exceptional consistency and recovery in determining NO2− concentrations in commercial samples. The radical scavenging activity of the CDs is assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) tests, revealing robust antioxidant activity (~78 % DPPH) and (>80 % for ABTS). Furthermore, cell viability is evaluated through the metabolic activity of fibroblast (NIH 3 T3) cells. Due to their antioxidant properties and low toxicity to human cell lines, these CDs represent a versatile and useful tool for biomedical research.

Magnetic Field Induced Dielectric Polarization to Enhance Raman Detection of Nitrite by NiFe2O4@Ag

AbstractRapid and accurate detection of nitrite in the aqueous environment is extremely important for ecological safety and human health. In this paper, the Raman detection of nitrite by a NiFe2O4@Ag sensor in water is enhanced by an extra magnetic field collaborated with surface plasma. Most importantly, it is demonstrated that the magnetic field enhances the Raman peak intensity through not only the effect of magnetic aggregation but also the magnetic field‐induced dielectric polarization effect. In this way, the NO2− can be detected in a wide linear range from 10−8 to 10−3 mol L−1, and the limit of detection (LOD) can reach as low as 1.25 × 10−9 mol L−1, which is 5.69 times lower than that in the absence of an external magnetic field. Similarly, the sensitivity under the magnetic field is 2.65 times that without the magnetic field. In addition, the sensor also shows superior detection ability to NO2− in real samples. Given the excellent capability of the magnetic field‐enhanced Raman spectra, the reported strategy offers new thoughts on how to enhance the detection ability by an external magnetic field and show the great application potential in real water bodies.

Carbon dots-based dual-mode sensor for highly selective detection of nitrite in food substrates through diazo coupling reaction

As an antioxidant and preservative agent, nitrite (NO2−) plays an essential role in the food industry to maintain freshness or inhibit microbial growth. However, excessive addition of NO2− is detrimental to health, so accurate and portable detection of NO2− is critical for food quality control. Notably, the selectivity of most carbon dots (CDs)-based fluorescence sensors was not enough due to the nonspecific interaction mechanism of hydrogen bond, electrostatic interaction and inner filter effect etc. Herein, a novel fluorescence/UV–vis absorption (FL/UV–vis) dual-mode sensor was developed on basis of mC-CDs, which were prepared by simple solvothermal treatment of m-Phenylenediamine (m-PDA) and cyanidin cation (CC). The fluorescence of these mC-CDs could be selectively responded by NO2− through the specific diazo coupling reaction between NO2− and amino groups on the surface of mC-CDs, thus effectively improving the selectivity of NO2− detection. The CDs-based fluorescence sensor possessed a low detection limit of 0.091 μM and 0.143 μM for FL and UV–vis methods and the excellent linear range of 0.0–60.0 μM. Furthermore, the mC-CDs sensor was employed to detect NO2− in real samples with a recovery rate of 97.11 %–104.15 % for quantitative addition. Moreover, the smartphone-assisted fluorescence sensing platform developed could identify the subtle color changes that could not be distinguished by the naked eye, and had the advantages of fast detection speed and intelligence. More importantly, the portable solid phase sensor based on mC-CDs had been successfully applied to the specific fluorescence identification and concentration monitoring of NO2−. Accordingly, the designed sensor provided a new strategy for the highly selective and convenient sensing of NO2− in food substrates, and paved the way for the wide application of CDs-based nanomaterials in the detection of food safety.