Detection Of Sulfite Research Articles

Electrochemical Detection of Sulfite Using Ni-Ru-Based Heterometallo-Supramolecular Polymer

We have fabricated a Ni (II)-Ru(II)-based heterometallo-supramolecular polymer (HMSMP)-modified glassy carbon electrode for the selective and sensitive electrochemical detection of sulfite (SO3 2-). The modified electrode (polyNiRu/GCE) was characterized by using scanning electron microscopy (SEM) and fourier transmission infrared (FT-IR) spectroscopy. Molecular weight of synthesized polymer (4.77 × 105 Da) was measured through intrinsic viscosity measurement following Mark-Houwink equation. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the electrochemical behavior of the modified electrode. The modified electrode showed high sensitivity of 0.06 µAµM-1cm-2 for SO3 2-. The detection limit (S/N = 3) for SO3 2- was 0.97 µM with a linear range of 10 to 1000 µM. The developed sensor was successfully examined for real sample analysis with tap water. Excellent recovery with lower relative standard deviation (RSD) and high stability for 4000s in analytic solution confirmed the reliability of using this polyNiRu/GCE in practical assessment.

Electrochemical sensor for sensitive nitrite and sulfite detection in milk based on acid-treated Fe3O4@SiO2 nanoparticles

In this work, a simple electrochemical sensing platform based on acid-treated Fe3O4@SiO2 nanoparticles was successfully prepared for nitrite and sulfite detection. Fe3O4@SiO2 nanoparticles were synthesized through the sol–gel and hydrothermal methods. Fe3O4@SiO2 presented positive charges after acid treatment, which could enhance the electrostatic attraction between Fe3O4@SiO2 and nitrite and sulfite. The Fe3O4@SiO2(acid-treated) modified magnetic glassy carbon electrode (MGCE) was applied to detect nitrite and sulfite using differential pulse voltammetry and cyclic voltammetry. Under optimized conditions, the developed electrochemical sensor presented good analytical properties for nitrite and sulfite detection with detection limits of 3.33 μmol/L and 31.57 μmol/L, respectively. The good recoveries varied from 85.18% to 111.02%, with a relative standard deviation of 0.23–4.80%. Furthermore, the Fe3O4@SiO2(acid-treated) modified MGCE showed better selectivity, reproducibility, and repeatability in nitrite and sulfite detection. Therefore, this proposed electrochemical sensor provides a new method for developing a nitrite and sulfite detection sensor.

Copper Immobilized over 2D Hexagonal SBA-15 for Electrochemical and Colorimetric Sulfite Sensing.

Sulfite (SO32-) is considered a highly toxic anion for living organisms. Herein, we report the synthesis of copper immobilized over a 2D hexagonally ordered mesoporous silica material CuMS as an electrochemical and colorimetric dual-technique-based sensing platform for sulfite detection. The immobilization of copper on silica was achieved through the bis[3-(triethoxysilyl)propyl]tetrasulfide (TEPTS) ligand. Morphological and physical properties of the material were confirmed by several characterization techniques, including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, N2 sorption, and X-ray photoelectron spectroscopy. The CuMS material retained mesoporosity with a narrow pore size distribution (D ≈ 5.4 nm) and a high Brunauer-Emmett-Teller surface area of 682 m2 g-1 after the immobilization of copper. The prepared catalyst shows promising electrocatalytic activity toward sulfite oxidation. A linear variation in the peak current was obtained for SO32- oxidation in the 0.2-15 mM range with a high sensitivity of 62.08 μA cm-2, under optimum experimental conditions. The limit of detection (LOD) was found to be 1.14 nM. CuMS also shows excellent activity toward colorimetric detection of sulfite anions with an LOD of 0.4 nM. The proposed sensor shows high selectivity toward the sulfite anion, even in the presence of common interferents. The detection of sulfite in white wine with excellent recovery demonstrates the practical applicability of this sensor.

Fabrication of Ag nanostar and PEI-based SERS substrate for sensitive and rapid detection of SO2: Application for detection of sulfite residues in beer

Because of sulfite's potential toxicity, there is a growing concern about detecting and controlling its concentration in foods, alcoholic beverages, pharmaceuticals, and environmental samples to ensure public health. A branched polyethyleneimine-coated silver nano-star (AgNS@PEI) surface-enhanced Raman scattering (SERS) substrate was synthesized in this study for use as a sensitive, simple, rapid, stable, and reproducible non-destructible sulfite detection analytical technique. The seed morphology of the nano-star was created by using hydroxylamine (NH2OH) solution as a primary reducing agent, followed by a slow secondary reduction by trisodium citrate dihydrate (HOC(COONa)(CH2COONa)2 2H2O), resulting in the complete growth of the silver nano-star. For extra stability and selective absorption of sulfur dioxide from the headspace extraction of SO2 from sulfites, the nano-stars were thin coated with branched polyethyleneimine (b-PEI). The results showed that the thin-coated plasmonic substrates selectively absorb sulfur dioxide molecules, allowing sulfites in beer samples to be detected with a detection limit of 0.48 mg/L. Furthermore, the PEI-coated silver nano-star demonstrated increased stability and reproducibility, allowing for longer use of the substrate. Recovery experiments with recovery rates ranging from 95 to 112% and relative standard deviations ranging from 1.55 to 8.1% demonstrated that headspace extraction, selective SO2 absorption by the synthesized substrate, and subsequent SERS detections were reliable and valid for practical applications. Finally, this study developed an SO2-sensitive, selective, and robust Si@AgNS@PEI substrate for effective SERS detection and monitoring of sulfite levels in real-world environmental samples.

Biofunctionalisation of Polypyrrole Nanowires Array with Sulfite Oxidase Coupled with the Integration of Platinum Nanoparticles for Ultrasensitive Amperometric Detection of Sulfite

Sulfite determination in foods and alcoholic beverages is a common requirement by food and drug administration organisations in most countries. In this study, the enzyme, sulfite oxidase (SOx), is used to biofunctionalise a platinum-nanoparticle-modified polypyrrole nanowire array (PPyNWA) for the ultrasensitive amperometric detection of sulfite. A dual-step anodisation method was used to prepare the anodic aluminum oxide membrane used as a template for the initial fabrication of the PPyNWA. PtNPs were subsequently deposited on the PPyNWA by potential cycling in a platinum solution. The resulting PPyNWA-PtNP electrode was then biofuntionalised by adsorption of SOx onto the surface. The confirmation of the adsorption of SOx and the presence of PtNPs in the PPyNWA-PtNPs-SOx biosensor was verified by scanning electron microscopy and electron dispersive X-ray spectroscopy. Cyclic voltammetry and amperometric measurements were used to investigate the properties of the nanobiosensor and to optimise its use for sulfite detection. Ultrasensitive detection of sulfite with the PPyNWA-PtNPs-SOx nanobiosensor was accomplished by use of 0.3 M pyrrole, 10 U mL−1 of SOx, adsorption time of 8 h, a polymerisation period of 900 s, and an applied current density of 0.7 mA cm−2. The response time of the nanobiosensor was 2 s, and its excellent analytical performance was substantiated with a sensitivity of 57.33 μA cm−2 mM−1, a limit of detection of 12.35 nM, and a linear response range from 0.12 to 1200 μM. Application of the nanobiosensor to sulfite determination in beer and wine samples was achieved with a recovery efficiency of 97–103%.

A paper-based colourimetric sensor for sodium sulfite detection in beverages

Sulfite is a common food additive that prevents oxidation from damaging food nutrients, and it has long been used in the food industry as a bleaching agent. It can harm the human body if taken wrongly or excessively. In this study, three dyes (cresol red, chlorophenol red, and bromocresol green) were explored to analyze the presence of sodium sulfite (SS) in an inexpensive, disposable paper sensor with a lower visible detection limit of 0.05 M. This visual paper sensor detects sodium sulfite with high selectivity and sensitivity at room temperature. An IoT-based sensor was also developed to practically apply the developed method, which is rapid and low-cost and can replace heavy-duty instruments. Both these sensors can substantially impact scenarios such as food quality monitoring and detecting sodium sulfite in medicinal items.Graphical

Imaging and detection of sulfite in acute liver injury with a novel quinoxaline-based fluorescent probe

Herein, a novel fluorescent probe HZY was developed for monitoring the sulfite (SO32−) dynamics. For the first time, the SO32− triggered implement was applied in the acute liver injury (ALI) model. The levulinate was selected to achieve the specific and relatively steady recognition reaction. With the addition of SO32−, the fluorescence response of HZY exhibited a large Stokes shift of 110 nm under the 380 nm excitation. The merits included high selectivity under various pH conditions. Compared with the reported fluorescent probes for sulfite, HZY indicated above-moderate performances including remarkable and rapid response (40 folds, within 15 min), and high sensitivity (limit of detection = 0.21 μM). Further, HZY could visualize the exogenous and endogenous SO32− level in living cells. Moreover, HZY could gauge the changing levels of SO32− in three types (induced by CCl4, APAP, and alcohol) of ALI models. Both in vivo imaging and depth-of-penetration fluorescence imaging demonstrated that HZY could characterize the developmental and therapeutic status during the liver injury process by measuring the dynamic of SO32−. The successful implementation of this project would promote the accurate in-situ detection of SO32− in liver injury, which was expected to guide the pre-clinical diagnosis and clinical practice.

Porphyrin based metal-organic frameworks as an enhanced fluorescence nanoprobe for highly sensitive detection of sulfite

Development of a facile and effective strategy for highly sensitive detection of sulfite (SO32−) in food is of great significance to human health. Herein, fluorescent porphyrin-based MOFs (PCN-224) was synthesized and further developed as an enhanced fluorescence sensor for SO32− detection. The fluorescence peak of PCN-224 locates at 664 ​nm. In the presence of SO32−, the acid-base reaction between H2PO4− and SO32− promotes the generation of PO43−, thus forming Zr-OP bonds and enhancing the fluorescence intensity of PCN-224 at 664 ​nm. Therefore, H2PO4− is used as an auxiliary agent to construct the sensing system PCN-224/H2PO4−. The fluorescence enhancement of PCN-224/H2PO4− shows a good linear relationship in the range of 0.01–18 ​μM and the limit of detection is as low as 3.8 ​nM. In addition, the constructed PCN-224/H2PO4− sensor system can be successfully used for SO32− detection in the granulated sugar with a recovery ranging from 100.17% to 106.25%, demonstrating the feasibility of PCN-224/H2PO4− nanosensor for SO32− detection in real sample analysis.

Oxygen vacancies rich Co-Mo metal oxide microspheres as efficient oxidase mimetic for colorimetric detection of sulfite

Modulation of surface oxygen vacancies (Ov) by defect engineering is an attractive strategy for designing high performance transition metal oxide nanozymes. In this work, we reported the fabrication of the CoMoO4 oxidase-like nanozyme, i.e. CoMo-300r, by first pyrolyzing the CoMo layered double hydroxide precursor in an air atmosphere at 300 °C and subsequent NaBH4 reduction strategy. Various characterization outcomes confirm the mesoporous structures of both CoMo-300r and no NaBH4 treated CoMo-300, while the specific surface area of CoMo-300 is significantly increased from 103.54 m2·g−1 to 165.24 m2·g−1 after NaBH4 reduction. Also, NaBH4 reduction treatment leads to the formation of Ov rich CoMoO4 and reduced metal ion species on the surface, promoting the redox reaction kinetics. The CoMo-300r prepared at a molar ratio of Co to Mo of 1:2, pyrolysis temperature of 300 °C and 10 mM NaBH4 exhibited the best oxidase-like activity. The oxidase-like activity of CoMo-300r is 2.6-fold times that of no NaBH4 treated optimal CoMo-300. The CoMo-300r can effectively promote TMB oxidation to produce blue color and has the Michaelis-Menten constant of 0.0428 mM, which was lower than most cobalt-based oxide nanozymes and indicated a higher affinity for TMB. In terms of inhibition of SO32− on the CoMo-300r/TMB system, a sensitive SO32− colorimetric sensing platform was established. The linear range and limit of detection for sulfite determination were 0.2–40 μM and 0.09 μM, respectively. The relative standard deviation for the determination of 10 μM sulfite was 1.41% (n = 11). The method was successfully applied to the detection of sulfite in white wine. This work provides a new strategy to fabricate high activity oxidase mimetic for food analysis.

Анализ стандартов Евразийского экономического союза на кондитерские изделия

A barrier-free trade in the Eurasian Economic Union (EAEU) market is impossible without a unified approach to standardization. The research objective was to analyze and develop proposals that would make it possible to unify the standards of the Eurasian Economic Commission (EAEC) on the content of sulfur dioxide and sulfites in confectionery products.
 The study featured technical regulations and standards for confectionery products, methods for determining sulfur dioxide, and EAEU resources on the results of control oversight activities. The methods included comparison, analogy, analysis, synthesis, peer review, integrated standardization, and system analysis.
 The analysis involved the official websites of the authorized bodies of the EAEU states on control and supervisory measures for compliance with technical regulations. It revealed the main reasons behind the limited confectionery turnover associated with excessive sulfur dioxide and sulfites. The standards showed discrepancies with Technical Regulations of Customs Union TR CU 022/2011 and TR CU 029/2012. The content standards for sulfur dioxide and sulfites in finished products were different. The analysis detected no unified approach to indicators, measurement units, and detection methods. The authors also assessed the advantages and disadvantages of the existing domestic State Standards for methods of sulfur dioxide and sulfite detection in confectionery products. The state standards have to be adapted to the international standards and EU Directives, in particular, by certifying the Monier-Williams method.
 The results can help to unify national and international regulations in order to remove technical barriers in the EAEU market and increase the export volume. They also can help confectionery producers to improve the quality and safety of confectionery products.

Porous g-C3N4 Nanosheets for On–Off–On Fluorescence Detection and Elimination of Chromium(VI) and Sulfite

Porous g-C₃N₄ Nanosheets for On–Off–On Fluorescence Detection and Elimination of Chromium(VI) and Sulfite

Electrochemical Detection of Sulfite by Electroreduction Using a Carbon Paste Electrode Binder with N-octylpyridinium Hexafluorophosphate Ionic Liquid

Sulfite is a widely used additive in food and beverages, and its maximum content is limited by food regulations. For this reason, determining the sulfite concentration using fast, low-cost techniques is a current challenge. This work describes the behavior of a sensor based on an electrode formed by carbon nanotubes an ionic liquid as binder, which by electrochemical reduction, allows detecting sulfite with a detection limit of 1.6 ± 0.05 mmol L−1 and presents adequate sensitivity. The advantage of detecting sulfite by reduction and not by oxidation is that the presence of antioxidants such as ascorbic acid does not affect the measurement. The electrode shown here is low-cost and easy to manufacture, robust, and stable.

Electrochemical detection of sulfite in food samples

In various pharmaceutical and food industries, sulfite is utilized for the inhibition of nonenzymatic and enzymatic browning. Also, in brewing industries, it acts as an antioxidizing and antibacterial agent. Several toxic and adverse reactions, including vitamin deficiency, hypersensitivity, and allergic diseases, have been attributed to sulfite ingestion that may cause dysbiotic oral and gut microbiota events. Thus, the content of sulfite in foods must be controlled and monitored, and it is essential to find a specific, reproducible, and sensitive method to detect sulfite. Some analytical solutions are being tested to quantify sulfite. However, due to their advantage over traditional techniques, electroanalytical techniques are attracting much attention because they are simple, fast, affordable, and sensitive to implement. In addition, by the electrode modification, the morphology and size can be controlled, resulting in the miniaturization to be used in portable electrochemical devices. Therefore, the present review addressed some articles on the electrooxidation of sulfite from real samples using various electrochemical sensors.

A simple and stable chemiluminescence resonance energy transfer system based on Ce(IV)-MOFs for detection of sulfite

Chemiluminescence (CL) is an effective way for designing sulfite (SO32-) sensors. However, the practical application of these sensors was hampered so far due to the poor selectivity or stability of the probes (e.g., KMnO4 and Ce4+). In this work, the Ce(IV)-MOF was fabricated through a simple and time-saving hydrothermal synthetic method. The special structure of Ce(IV)-MOF endowed it with high selectivity and stability in the CL reaction. Based on chemiluminescence resonance energy transfer (CRET) from the luminescent intermediate of the CL system to dyes (Nile blue, and rhodamine B), a simple, stable and sensitive CL sensing platform for SO32- was successfully established. The proposed CL sensing platform with the outstanding CL efficiency hold great potential for detecting SO32- in complex samples. This study not only broadened the application of MOF in CL field, but also provided a new clue for the design of stable CL system and CRET process.

Small-Molecule Fluorescent Probe for Detection of Sulfite.

Sulfite is widely used as an antioxidant additive and preservative in food and beverages. Abnormal levels of sulfite in the body is related to a variety of diseases. There are strict rules for sulfite intake. Therefore, to monitor the sulfite level in physiological and pathological events, there is in urgent need to develop a rapid, accurate, sensitive, and non-invasive approach, which can also be of great significance for the improvement of the corresponding clinical diagnosis. With the development of fluorescent probes, many advantages of fluorescent probes for sulfite detection, such as real time imaging, simple operation, economy, fast response, non-invasive, and so on, have been gradually highlighted. In this review, we enumerated almost all the sulfite fluorescent probes over nearly a decade and summarized their respective characteristics, in order to provide a unified platform for their standardized evaluation. Meanwhile, we tried to systematically review the research progress of sulfite small-molecule fluorescent probes. Logically, we focused on the structures, reaction mechanisms, and applications of sulfite fluorescent probes. We hope that this review will be helpful for the investigators who are interested in sulfite-associated biological procedures.

Selective detection of metal ions, sulfites and glutathione with fluorescent pyrazolines: a review

Selective detection of metal ions, sulfites and glutathione with fluorescent pyrazolines: a review

A Novel Carbon Paste Electrode-Modified Electrocatalytic CO–Ce–NPs for Sulfite Detection: A Sonochemical Synthesis

A Novel Carbon Paste Electrode-Modified Electrocatalytic CO–Ce–NPs for Sulfite Detection: A Sonochemical Synthesis

Dual-functional turn-on fluorescent probe for discriminative sulfite and sulfide detection via organic/aqueous ratio tuning and its application in real samples

Sulfite and sulfide are substances commonly present in food, biological and industrial processes. While excess amounts of these anions can elicit physiological disorders in humans, there are only limited examples of probes capable of selectively detecting both of them. In this study, we present a sulfite/sulfide dual-functional probe 1 based on a dimethylaminonaphthalene-oxazaborine fluorophore and a dicyanovinyl reaction site. Probe 1 enabled a highly selective detection of sulfite under acetonitrile/tris buffer (85:15, v/v), discriminating sulfite from common interfering species such as sulfide, cyanide, and biothiols. The probe fully responded to sulfite within 4 min, with an 18-fold increase in the fluorescence intensity. Besides, probe 1 was also able to selectively sense sulfide in pure acetonitrile, while displaying a detection limit as low as 96 nM. Mechanistic studies revealed that a large 170 nm Stokes shift of the probe after sulfite/sulfide detection can be ascribed to the nucleophilic addition of sulfite/sulfide to the dicyanovinyl moiety, which broke the conjugation system between the fluorophore scaffold and the dicyanovinyl group, thereby triggering the intramolecular charge transfer effect. Finally, the probe displayed good capability for sensing sulfite and sulfide in real samples with good recoveries, proving its potential in the determination of sulfite and sulfide concentrations for real-life applications.

Surface amplification of graphite screen printed electrode using reduced graphene oxide/polypyrrole nanotubes nanocomposite; a powerful electrochemical strategy for determination of sulfite in food samples

The present research presents synthesis and substantial utilization of a nanocomposite of reduced graphene oxide/polypyrrole nanotubes to modify graphite screen printed electrode (rGO/PPy NTs-GSPE) for detection of sulfite. The nanocomposite preparation was done by hydrothermal protocol, followed by characterization by energy-dispersive X-ray (EDX) and field emission-scanning electron microscopy (FE-SEM). Electrocatalytic sensing of sulfite is carried out using differential pulse voltammetric (DPV), linear sweep voltammetry (LSV), cyclic voltammetric (CV), and Chronoamperometry. Electrochemical behaviors of modified and unmodified electrodes were explored with CV method. In addition, DPV was employed for anodic peak and quantitatively detecting sulfite. The DPV results unveiled a linear response of the sensor to various sulfite contents (0.04–565.0 μM) with a narrow detection limit (0.01 μM) and admirable sensitivity (0.0483 μA/μΜ). The diffusion coefficient (D) for sulfite using rGO/PPy NTs-GSPE, 9.9 × 10−6 cm 2/s was obtained. The sensor was also successful in the sulfite detection in real specimens.

A fluorescent probe derived from benzofuranone for turn-on detection of sulfite in living cells and mice

A novel benzofuranone fluorescent probe, BFO-SFT, for monitoring sulfite in living cells and mice is described which operates over a wide pH range and exhibits a red-shifted emission maximum. The response of the probe BFO-SFT was relatively rapid (within 20 min) and exhibited a good linear correlation of 0–10 Eq (100 μM) with reliable accuracy (R2 = 0.9934). The probe also showed high sensitivity (Limit of detection = 152 nM) and selectivity. With low cytotoxicity, BFO-SFT was successfully applied into the biological imaging of sulfite in living MCF-7 cells and in BALB/C Nude mice.