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The C3-symmetry ionic polymer PPyTri has been designed with multi-walled carbon nanotubes (MWCNTs) or graphene nanoplatelets (GNPs) and studied as an ultrasensitive electrochemical sensor for trace Hg(II) detection. The synthesis approach incorporated attaching three pyridinium cationic components with chloride anions to the triazine core. The precursors, BPy, were synthesized using a condensation process involving 4-pyridine carboxaldehyde and focused nicotinic hydrazide. The polymer PPyTri was further modified with either MWCNTs or GNPs. The resulting ionic polymer PPyTri and its fabricated nanocomposites were characterized using infrared (IR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and powder X-ray diffraction (XRD). The analysis revealed that both the polymer and its nanocomposites have semi-crystalline structures. The electroactivity of the designed nanocomposites toward Hg + 2 ions revealed that among the nanocomposites and bare copolymer, the glassy carbon electrode (GCE) adapted with the PPyTri GNPs-5% exhibited the greatest current response over a wide range of Hg + 2 concentrations. The nanocomposite-modified electrode presented an excellent sensitivity of 83.33 µAµM − 1 cm − 2, a low detection limit of 0.033 nM, and a linear dynamic range of 0.1 nM to 0.01 mM (R2 = 0.9945). [ABSTRACT FROM AUTHOR]

Sunset Yellow (SY) is an azo dye used in various food and pharmaceutical industries that deserves special attention because of its allergic and carcinogenic properties. Recently, electrochemical techniques have come to the spotlight because of their high sensitivity, simplicity and rapidity as compared to other techniques. In this work, we have developed a cost‐effective and stable electrochemical sensor by a simple method using Vitamin B12‐derived cobalt oxide coupled with g‐C3N4 (V12‐CoO/gCN) modified Au electrode. The composite prepared for the sensor was characterized using techniques such as FTIR, Powder XRD, SEM analysis, EDAX, and mapping. For electrochemical sensing of the dye Sunset Yellow, CV, DPV, and LSV techniques have been used, out of which DPV shows a better detection limit of 1.39 nM followed by LSV and CV that displayed detection limits of 3.3 nM and 4.14 nM respectively. When 5 real samples obtained from the local market are analyzed using the DPV technique, the detection limit is obtained in the range between 2.1 nM and 6.9 nM. This method leads to the development of an electrochemical sensor for the detection of Sunset Yellow to get a lower detection limit that can be used in food toxicology and related fields. [ABSTRACT FROM AUTHOR]

Uracil (U) in DNA plays an important role in numerous biological processes. It can be introduced through two primary mechanisms, cytosine deamidation and misincorporation of dUMP during DNA replication. The misincorporation of U in DNA is associated with various diseases, especially cancer. Here, we developed an electrochemical method utilizing a modified electrode with self-assembled gold nanoparticles on covalent organic frameworks (COF-V-AuNPs) for the direct detection of U. The COF-V-AuNP composite offers numerous advantages, such as exceptional stability, abundant π-functional sites, excellent conductivity, a high specific surface area, a porous structure, and a strong non-covalent affinity, all of which facilitate sensitive detection of U. This electrochemical method achieves a detection limit of 1.92 μM for U. Furthermore, the method was successfully applied to the detection of U using human serum samples as matrices, indicating its potential for clinical applications. [ABSTRACT FROM AUTHOR]

The C3-symmetry ionic polymer PPyTri has been designed with multi-walled carbon nanotubes (MWCNTs) or graphene nanoplatelets (GNPs) and studied as an ultrasensitive electrochemical sensor for trace Hg(II) detection. The synthesis approach incorporated attaching three pyridinium cationic components with chloride anions to the triazine core. The precursors, BPy, were synthesized using a condensation process involving 4-pyridine carboxaldehyde and focused nicotinic hydrazide. The polymer PPyTri was further modified with either MWCNTs or GNPs. The resulting ionic polymer PPyTri and its fabricated nanocomposites were characterized using infrared (IR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and powder X-ray diffraction (XRD). The analysis revealed that both the polymer and its nanocomposites have semi-crystalline structures. The electroactivity of the designed nanocomposites toward Hg + 2 ions revealed that among the nanocomposites and bare copolymer, the glassy carbon electrode (GCE) adapted with the PPyTri GNPs-5% exhibited the greatest current response over a wide range of Hg + 2 concentrations. The nanocomposite-modified electrode presented an excellent sensitivity of 83.33 µAµM − 1 cm − 2, a low detection limit of 0.033 nM, and a linear dynamic range of 0.1 nM to 0.01 mM (R2 = 0.9945).

Decarboxylative cross‐coupling reactions are powerful tools for carbon‐heteroatom bonds formation, but typically require pre‐activated carboxylic acids as substrates or heteroelectrophiles as functional groups. Herein, we present an electrochemical decarboxylative cross‐coupling of carboxylic acids with structurally diverse fluorine, alcohol, H2O, acid, and amine as nucleophiles. This strategy takes advantage of the ready availability of these building blocks from commercial libraries, as well as the mild and oxidant‐free conditions provided by electrochemical system. This reaction demonstrates good functional‐group tolerance and its utility in late‐stage functionalization. [ABSTRACT FROM AUTHOR]

Currently reported adsorption (hydroxyl or amidoxime) groups must dissociate hydrogen ions to form ─O− units for the coordination with uranyl ions. However, this process suffers a high energy barrier for bond dissociation, leading to the sluggish uptake speed and low adsorption capacity for uranium extraction from natural seawater. Herein, this study proposes a strategy for electrochemical modulation of adsorption sites, which overcomes the chemical dissociation processes of hydrogen ions. Poly‐2,5‐dihydroxy‐1,4‐benzoquinone containing redox carbonyl groups is intercalated into the channels of a covalent organic framework (COF) through in situ cross‐linking of 2,5‐dihydroxy‐1,4‐benzoquinone. Under electrochemical modulation, the C═O groups are transformed into adjacent phenol–oxygen anions to cooperate with the coordination atoms (O and N) on the COF channel for rapid binding of uranyl ions, which gave an absorption rate of 4.2 mg g−1 d−1 (≈3.3 ppb of uranium in natural seawater). Notably, the COF‐based electrodes delivered an average capacity of ≈20.8 mg‐U per g for uranyl ion adsorption during 5 days of extraction, ≈3000 times larger than that of classical tannin‐based adsorbents. The proposed method for preparing electrochemically modulated binding sites is expected to provide guidance for designing high‐efficiency adsorbents in the future. [ABSTRACT FROM AUTHOR]

A novel modified polyaspartic acid (PASP/CD) was synthesized from thiocarbazide and polysuccinim-ide. Secondly, the structure of PASP/CD was characterized by infrared spectroscopy (FT1R) and hydrogen nuclear magnetic resonance spectroscopy (NMR). Finally, the corrosion inhibition behavior of PASP/CD on carbon steel was studied by gravimetry, electrochemical method, atomic force microscope (AFM), contact angle and scanning electron microscope and energy spectrum (SEM/EDS) in 0.5 mol/L hydrochloric acid solution. The results show that when PASP/CD is added into hydrochloric acid solution as a mixed corrosion inhibitor, the charge transfer resistance of the system increases significantly. When the concentration of PASP/CD is 80 mg/L, the corrosion inhibition efficiency reaches 91.48%, which is much higher than PASP. Compared with PASP, the corrosion inhibition performance of PASP/CD is less affected by temperature. The figures and roughness data of AFM show that PASP/CD has good corrosion inhibition performance. It is found that the inhibition effect of PASP/CD is due to the physical and chemical adsorption of new functional groups on the steel surface. This work provides technical support for broadening the comprehensive properties of green water treatment agent polyaspartic acid. [ABSTRACT FROM AUTHOR]

Dietary supplements are drastically growing as a category of consumer products all over the world. The abuse of supplements marketed for slimming purposes and physical fitness has been observed worldwide in recent years, which raises concerns in terms of public health. In this study, different types of dietary supplements marketed and delivered through the e-commerce were studied for the determination of thallium as a hazardous inorganic contaminant. The total content of thallium was determined by a sensitive voltammetric method after a microwave-assisted oxidative digestion of the sample. In addition, a comparative spectrometric method was applied for validation of the results in the samples. The maximum concentration found for thallium was found to be 2.89 mg kg−1, which well agree with the comparative measurement. Considering the 32 studied formulations, it can be pointed out that ∼24% of the of dietary supplements presented Tl concentrations at concentrations higher than 1 mg kg−1. The results permitted the assessment of the health risk related to thallium from contaminated samples, based on the calculation of the estimated daily intake (EDI) and the risk quotient (HQ). The highest daily intake of thallium was calculated as 82.0 µg day−1 in a protein-based supplement, which is equivalent to an EDI of 1.17 µg kg−1 day−1. This work highlights the need to develop regulations on the limits of toxic elements such as thallium in widely consumed dietary supplements, as well as an in-depth look at the adverse effects caused by this element in the human body. [ABSTRACT FROM AUTHOR]

In the current study, we utilize leaves of Aerva lanata as the precursor to produce carbon dots (CDs) adopting a one-step hydrothermal approach without the use of extra chemical reagents or surface modification. They have hydroxyl and carboxyl groups as surface functionalities, were well soluble in water, were biocompatible, and exhibited bright fluorescence. The applications of the prepared CDs in three broad areas were carefully described. As a fluorescence-based sensor, the prepared sensor was able to sense ciprofloxacin. Ciprofloxacin enhanced the fluorescent intensity of CDs, and a linear correlation between the intensity of fluorescence and the concentration of ciprofloxacin in a wide range with an LOD of 0.4 nM was observed. The mechanism behind the fluorescence enhancement seen with the addition of ciprofloxacin was revealed to be charge transfer and hydrogen bonding. As an electrochemical probe, a carbon dot-modified glassy carbon electrode was able to sense copper ions with good selectivity and an LOD of 4 nM. Cu(II) electrochemical sensing was comprehensively examined, with a complete description of the electron transport process. The anticounterfeiting properties of the synthesized CDs were also proven. The successful real sample analysis also paved the way for an environment-friendly sensor for exhibiting its potential for multifaceted applications. This study not only introduced a new carbon dot to improve our understanding of material properties but also delved into all of its possible applications. [ABSTRACT FROM AUTHOR]

Silver/polyvinyl alcohol (Ag/PVA) nanocomposites were fabricated via an electrochemical method. Silver nanoparticles (AgNPs) with varying grain sizes were directly synthesized within PVA polymer matrices at deposition times of 15, 30, 45, 60, and 120 minutes. The integration of AgNPs within the PVA matrix was confirmed through Transmission Electron Microscopy (TEM) and optical absorbance measurements. X-ray Diffraction (XRD) analysis demonstrated the face-centered cubic structure of AgNPs. Furthermore, these prepared nanocomposites exhibited significant antibacterial properties against Bacillus subtilis and Pseudomonas pneumonia, as well as antifungal activity against Alternaria alternata. Remarkably, the AgNPs/PVA nanocomposite exhibited outstanding antifungal efficiency, resulting in an impressive inhibition zone of up to 47 mm.

The work presented an electrochemical anode method with different electrolyte concentrations and heat posttreatment to control the stoichiometry and structure of Cu2−xS electrocatalysts. X‐ray diffraction, X‐ray photoelectron spectroscopy, and scanning electron microscopy were employed to characterize the composition and morphology, whereas the electrocatalytic activity was evaluated by linear scanning voltammetry and electrochemical impedance spectroscopy. The results showed that the electrochemical method successfully synthesized thin flake‐shaped Cu7S4, which exhibited optimal performance at the electrolyte concentration of 0.45 mol L1 with maximum turnover frequency of 0.786 s−1, maximum mass activity of 0.539 A g−1, minimum charge transfer resistance of 0.156 Ω cm−2, and minimum overpotential of 154 mV at a current density of 10 mA cm−2. In the Cu7S4 structure, Cu2+ and S2− were coordinated in a CuS4 tetrahedral structure, whereas Cu+ and S2− were coordinated in a CuS3 triangular structure. Heat posttreatment could change the stoichiometry from 1.75 to 1.8 and improve the electrochemical performance. In the Cu9S5 structure, the CuS3 triangular structure had disappeared. Under the same conditions, the overvoltage was only 128 mV. [ABSTRACT FROM AUTHOR]

Silver/polyvinyl alcohol (Ag/PVA) nanocomposites were fabricated via an electrochemical method. Silver nanoparticles (AgNPs) with varying grain sizes were directly synthesized within PVA polymer matrices at deposition times of 15, 30, 45, 60, and 120 minutes. The integration of AgNPs within the PVA matrix was confirmed through Transmission Electron Microscopy (TEM) and optical absorbance measurements. X-ray Diffraction (XRD) analysis demonstrated the face -centered cubic structure of AgNPs. Furthermore, these prepared nanocomposites exhibited significant antibacterial properties against Bacillus subtilis and Pseudomonas pneumonia, as well as antifungal activity against Alternaria alternata. Remarkably, the AgNPs/PVA nanocomposite exhibited outstanding antifungal efficiency, resulting in an impressive inhibition zone of up to 47 mm. [ABSTRACT FROM AUTHOR]

Foodborne illnesses can be infectious and dangerous, and most of them are caused by bacteria. Some common food-related bacteria species exist widely in nature and pose a serious threat to both humans and animals; they can cause poisoning, diseases, disabilities and even death. Rapid, reliable and cost-effective methods for bacterial detection are of paramount importance in food safety and environmental monitoring. Polymerase chain reaction (PCR), lateral flow immunochromatographic assay (LFIA) and electrochemical methods have been widely used in food safety and environmental monitoring. In this paper, the recent developments (2013–2023) covering PCR, LFIA and electrochemical methods for various bacterial species (Salmonella, Listeria, Campylobacter, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli)), considering different food sample types, analytical performances and the reported limit of detection (LOD), are discussed. It was found that the bacteria species and food sample type contributed significantly to the analytical performance and LOD. Detection via LFIA has a higher average LOD (24 CFU/mL) than detection via electrochemical methods (12 CFU/mL) and PCR (6 CFU/mL). Salmonella and E. coli in the Pseudomonadota domain usually have low LODs. LODs are usually lower for detection in fish and eggs. Gold and iron nanoparticles were the most studied in the reported articles for LFIA, and average LODs were 26 CFU/mL and 12 CFU/mL, respectively. The electrochemical method revealed that the average LOD was highest for cyclic voltammetry (CV) at 18 CFU/mL, followed by electrochemical impedance spectroscopy (EIS) at 12 CFU/mL and differential pulse voltammetry (DPV) at 8 CFU/mL. LOD usually decreases when the sample number increases until it remains unchanged. Exponential relations (R2 > 0.95) between LODs of Listeria in milk via LFIA and via the electrochemical method with sample numbers have been obtained. Finally, the review discusses challenges and future perspectives (including the role of nanomaterials/advanced materials) to improve analytical performance for bacterial detection. [ABSTRACT FROM AUTHOR]

In this study, AuPt bimetallic nanocubes (AuPt NCBs) were successfully combined with graphene quantum dots (GQDs) by a simple and easy-to-implement method at 80 °C for 90 min. In particular, graphene quantum dots were synthesized by hydrothermal method at 190 °C for 8 h, using raw material from wheat flour which is eco-friendly, available and abundant in nature. Besides, AuPt bimetallic nanocubes in the form of AuPt core/shell nanocubes (AuPt NCBs) were generated from the reaction at 140 °C for 2 h by hydrothermal method. Furthermore, the synthesized AuPt NCBs/GQDs nanocomposites were also characterized, shape, size and composition by: UV–vis, FTIR, XRD, TEM, EDX, XPS, and AFM. The obtained results show that the Au nanocubes (Au NCBs) have an average size of ~ 39 nm; while, the average size of AuPt NCBs and GQDs are ~ 40–44 and ~ 3–5 nm, respectively. In addition, AuPt NCBs/GQDs nanocomposites were also used as non-enzymatic catalysts for the oxidation/reduction of glucose by cyclic voltammetry technique. The obtained results indicated that the AuPt NCBs/GQDs nanocomposites have high catalytic activity and are capable of detecting glucose in a wide concentration range from 10−12 to 1 M, with an extremely low limit of detection of concentration glucose levels (~ 10−12 M). Therefore, AuPt NCBs/GQDs are novel and promising materials that can be applied as catalysts with high activity oriented to many fields such as environmental treatment, fuel energy cells, or sensors to make bio-chip devices for early diagnosis of serious diseases such as diabetes, gout or cancer, etc., in present and the future. [ABSTRACT FROM AUTHOR]

Calcium carbonate (CaCO 3) is the most frequently occurring scaling in process equipment including cooling water systems. In this work, the kinetics of CaCO 3 precipitation (CCP) was investigated using chemical method in the absence and presence of green inhibitors including polyacrylic acid homopolymer (PAA), poly maleic acid homopolymer (PMA), polyacrylic acid: 2-acrylamido-2- methylpropane sulfonic acid copolymer (AA/AMPS) and polyacrylic acid:2-acrylamido-2-methylpropane sulfonic acid: t-butyl acrylamide terpolymer (AA/AMPS/TBAA). The effects of the solution composition, temperature, pH, and type of inhibitor agent on the inhibition efficiency were examined. Results showed that increasing immersion time, in a solution without inhibitor, decreased the concentration of Ca2+ and solution pH. However, the inhibitor increased the inhibition efficiency up to 96 h. Also, the effect of temperature was examined on the precipitation kinetic, and it was found that the rate of scaling formation increases with the increase in temperature from 25 to 55 °C. Scanning electron microscope (SEM) and energy dispersive X-ray (EDX) illustrated that morphology of CCP changed and calcite and aragonite scaling occurred at 55 °C under the influence of amide, carboxylic and sulfonic groups of the inhibitors. Moreover, the kinetics scaling in the presence of PMA was investigated by the electrochemical method and was compared with the chemical methods. The results of the chemical method in the current work are more reasonable than the electrochemical method. The study provides new insights into the mineral scaling kinetics by identifying the known parameters dependence of CaCO 3 scale formation processes. [Display omitted] • The calcium carbonate (CaCO 3) scaling kinetics with and without inhibitors was studied. • Anti-scaling kinetics of PMA, PAA, AA/AMPS and AA/AMPS/TBAA green inhibitors were reviewed and compared. • The effect of temperature on kinetic of CaCO 3 scaling was investigated. • SEM and EDX analyses revealed morphological alterations in CaCO 3 scaling, highlighting the role of inhibitor groups. • A method comparison showed the chemical approach as more reliable than electrochemical methods in studying scaling kinetics. [ABSTRACT FROM AUTHOR]

The analysis of enantiomers in food has significant implications for food safety and human health. Conventional analytical methods employed for enantiomer analysis, such as gas chromatography and high-performance liquid chromatography, are characterized by their labor-intensive nature and lengthy analysis times. This review focuses on the development of rapid and reliable biosensors for the analysis of enantiomers in food. Electrochemical and optical biosensors are highlighted, along with their fabrication methods and materials. The determination of enantiomers in food can authenticate products and ensure their safety. Amino acids and chiral pesticides are specifically discussed as important chiral substances found in food. The use of sensors replaces expensive reagents, offers real-time analysis capabilities, and provides a low-cost screening method for enantiomers. This review contributes to the advancement of sensor-based methods in the field of food analysis and promotes food authenticity and safety. [ABSTRACT FROM AUTHOR]

Bipyridine and related compounds are starting materials or precursors for a variety of valuable substances such as biologically active molecules, ligands for catalysts, photosensitizers, viologens, and supramolecular architectures. Thus, it is important to classify their synthesis methods and understand their characteristics. Representative examples include methods using homo and heterocoupling of pyridine derivatives in the presence of a catalyst. Because bipyridine compounds strongly coordinate with metal centers, a decrease in catalytic activity and yield is often observed in the reaction system. To address this issue, this review provides insights into advances over the last ~30 years in bipyridine synthesis using metal complexes under both homogeneous and heterogeneous conditions. Moreover, strategies for bipyridine synthesis involving sulfur and phosphorous compounds are examined. These alternative pathways offer promising avenues for overcoming the challenges associated with traditional catalysis methods, providing a more comprehensive understanding of the synthesis landscape. [ABSTRACT FROM AUTHOR]

The passivation behavior of steel reinforcements in concrete is significantly influenced by the environment, concrete pore solution, and the passive film formed on the steel surface. The present study used electrochemical methods to successfully characterize the passivation process of steel reinforcements in concrete. The passivation behavior of commonly used HRB400 steel reinforcement material in concrete was studied using various electrochemical parameters quantitatively. As the soaking test time increased, the OCP gradually increased and stabilized after 5 days, indicating that the steel electrode transitioned from an active state to a passive state in the simulated liquid environment of concrete. The steel reinforcement developed a protective passive film that reduced its tendency to corrode. According to EIS, after soaking for one day, the steel electrode showed significant early passivation, indicated by an increase in its arc diameter. The WE arc gradually increased in the first 5 days of immersion, suggesting dynamic passive film formation and development. Beyond 5 days, the passive film stabilized with minimal further changes in its impedance spectrum, indicating carbon steel electrode passivation. The working electrode's impedance increased significantly on the fifth day, and gradually increased slightly after 10 days, indicating comprehensive coverage by the oxide film. Attributed to the growth and development of the oxide film, the electrode resistance reached a relatively stable state after the fifth day. The shift in corrosion potential offers an indication of the level of passivation of the steel reinforcements. The decrease in the anode Tafel slope and increase in the corrosion potential indicate the formation and stabilization of an oxide film on the steel surface, which is beneficial for its long-term durability in concrete structures. By analyzing the OCP, EIS, and dynamic potential polarization curve method data, it is possible to gain insights into the passivation behavior of steel reinforcements in concrete structures. This study aims to provide a basis for optimizing the corrosion protection of steel reinforcements in concrete structures. The significance of this study lies in a deep understanding of the passivation behavior of steel bars in concrete, providing a theoretical basis for improving the durability and lifespan of steel bars in concrete structures. [ABSTRACT FROM AUTHOR]

The research paper focused on fabrication of an electrochemical sensor to sensing and monitoring of vanillin in aqueous solution. In this regard, NiO/nitrogen doped carbon quantum dots (NiO-NCQD) nanocomposite was synthesized as a highly conductive catalyst and used to modification of carbon paste electrode (CPE) and fabricated a sensitive voltammetric sensor. The oxidation signal of vanillin showed a catalytic activity at surface of NiO-NCQD/CPE compare to CPE in aqueous solution at pH = 7.0. The NiO-NCQD/CPE showed a linear range 0.01–280 µM, with a limit of detection (LOD) 5.0 nM, respectively. The NiO-NCQD/CPE was test to monitoring of vanillin in different food products and results compare with HPLC method. Results confirmed accuracy and precision suggested method to sensing of vanillin in food products. [ABSTRACT FROM AUTHOR]

Antioxidants are very beneficial for health as they protect the body from the effects of free radicals on various degenerative diseases caused by food contamination, air pollution, sunlight, etc. In general, methods for measuring the capacity of antioxidants generally use accurate methods such as spectrophotometry and chromatography. Still, this takes time, accurate sample preparation, and must be performed in a laboratory with particular expertise. Therefore, a new, more practical method needs to be developed for determining antioxidants, namely the electrochemical method. The electrochemical method is a promising method to develop because it comes with several advantages, including high sensitivity and fast response. The electrochemical method discussed in this article reviews sensors, biosensors, and nanosensors. This paper comprehensively analyzes contemporary developments in electrochemical biosensor techniques and antioxidant evaluation methodologies. The discussion centers on utilizing multiple biosensors. Electrochemical biosensors have been determined to be prevalent in analyzing food quality, assessing active factor functionality, and screening practical components. The present study outlines the difficulties linked with electrochemical bio-sensor technology and provides insights into the potential avenues for future research in this domain.

When exposed to corrosive environments, metals, which are relatively common industrial materials, undergo serious corrosion, leading to significant economic losses. Therefore, studying the corrosion rate of metals in their early stages holds great pedagogical significance. This study employs a standard specimen of 20# steel as an experimental object, designing the experimental teaching of metal corrosion rate under varying temperatures, PH levels, and hydrated salt materials. The weightlessness method determines the overall corrosion rate of the metal, while the electrochemical method determines the localized corrosion rate of the metal. When the experimental temperature is 80℃ and 100℃, the corrosion rate of 20# steel is the largest; both are 0.00800g·m−2·d−1, and the charge transfer resistance increases gradually when the temperature is −20℃~5℃, and decreases gradually when the temperature is 5℃~100℃. The corrosion rate of the metal did not change much at pH=7 and 8, and the corrosion rate reached 0.688 mm/a, and the impedance curve polarization resistance Rp was the smallest when pH=5, and its corrosion resistance was poor under acidic conditions. The average corrosion rates in MgSO4·7H2O, and CaCl2·6H2O and Ba(OH)2·8H2O were 0.0030g/m−2h−1, 0.0018g/m−2h−1, and 0.0050 g/m−2h−1, respectively. Teaching experiments were used to carry out the present study. The study aims to let students experience the process of metal corrosion through teaching experiments and better help them solve cognitive difficulties in metal corrosion.

The growth of Cu2O crystal planes was be controlled by adding surfactant to the NaCl solution in this manuscript. The structure and composition of the synthesized Cu2O particles were characterized by X‑ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and specific surface area test method (BET). The photocatalytic activities were evaluated by degrading methyl orange (MO) solution under magnetic stirring. The results shown that the synthesized Cu2O particle was spherical self-assembly structure when the surfactant was CTAB, and behaved higher degradation performance. Under dark conditions, the adsorption efficiency of 100 mg L–1 MO solution reached 67.08% in the first 1 min by 0.33 g L–1 CTAB-Cu2O, and after 15 min, the adsorption degradation efficiency of MO had reached 99.17%. The maximum adsorption capacity of CTAB-Cu2O was 297.28 mg g–1. The adsorption kinetics obeyed pseudo-second-order kinetics and followed the Freundlich isotherm. [ABSTRACT FROM AUTHOR]

Hydrogen serves as an important, clean energy carrier, which, however, has a challenge for its storage. Herein, we report the properties of ethylamine dehydrogenation (EDH) to acetonitrile under half-cell conditions and ethylamine electrolysis under full-cell conditions for fast, energy-efficient, ambient hydrogen release, which would couple with spontaneous acetonitrile hydrogenation to ethylamine for hydrogen uptake to realize hydrogen storage cycles under mild conditions. The influences of different reaction parameters on the EDH and ethylamine electrolysis properties are examined. The catalyst deactivation and regeneration mechanisms are investigated with aid of in situ ATR-FTIR characterizations. As fast as 309 μmol/h H 2 production rate with 97% faradaic efficiency (FE) from cathode and acetonitrile production with 100% FE from anode are achieved with a low 0.6 V cell voltage, demonstrating a great potential of this new electrochemical approach for hydrogen storage application. [Display omitted] • New knowledge of ethylamine dehydrogenation and electrolysis discovered. • Ethylamine enabled as liquid organic hydrogen carrier for ambient hydrogen storage. • Highly selective ethylamine electrolysis to hydrogen and acetonitrile achieved. • Efficient hydrogen production realized from ethylamine electrolysis. [ABSTRACT FROM AUTHOR]

Oxidative stress is a key pathophysiological process associated with the development and progression of inflammatory bowel disease (IBD). Biomarkers for oxidative stress, however, are scarce, as are diagnostic tools that can interrogate an individual's gut redox status. This proof-of-concept study aimed to evaluate the potential utility of an oxidation-reduction potential (ORP) measurement probe, to quantify redox status in the feces of both patients with IBD and healthy controls. Previous studies using this ORP measurement probe demonstrated promising data when comparing ORP from severely malnourished individuals with that of healthy controls. To date, ORP analyses have not been performed in the context of IBD. We hypothesized that measuring the ORP of fecal water in patients with IBD might have diagnostic value. The current study, however, did not show significant differences in ORP measurement values between patients with IBD (median [IQR] 46.5 [33.0–61.2] mV) and healthy controls (25 [8.0–52.0] mV; p = 0.221). Additionally, ORP measurements were highly unstable and rapidly fluctuated throughout time, with ORP values varying from +24 to +303 mV. Due to potential biological processes and limitations of the measuring equipment, this study was unable to reliably measure ORP. As a result, our findings indicate that ORP quantification may not be a suitable method for assessing fecal redox status and, therefore, does not currently support further exploration as a diagnostic or monitoring tool. [ABSTRACT FROM AUTHOR]

The properties and phosphate adsorption capability of the one-step method and electrochemical method in modifying peanut shell biochar have been determined. The one-step method deposits MgO and Fe3O4 onto biochar through chemical impregnation and regularly affects the functional groups and magnetic separation of biochar, thereby enhancing its ability to adsorb phosphate. In contrast, the electrochemical method is not favorable for modifying functional groups of biochar but can promote phosphate adsorption because of the formation of MgFe2O4 and Fe3O4 using electrolysis. The adsorption isotherm and kinetics data suggest that adsorption is monolayer onto a homogeneous surface and phosphate adsorption could be controlled by chemical processes. Biochar with the addition of both Fe2+ and Mg2+ shows better phosphate adsorption capability than those with barely any Fe2+ additions. It was concluded that the one-step method is a better modification method than the electrochemical method for enhancing the phosphate adsorption capability of biochars. [ABSTRACT FROM AUTHOR]

The transition of graphene from the lab to consumer goods is still a challenging job that necessitates efficient and cost-effective large-scale graphene production. This study combines electrochemical exfoliation in an aqueous solution of sulfuric acid (1M H2SO 4) and hydrogen peroxide (3% H2O 2) followed by thermal deoxygenation at a temperature of 800 ∘ C within the ambient environment. This method allows the inexpensive synthesis of pristine graphene for various industrial applications. X-Ray diffraction (XRD) results for pristine graphene showed a distinct peak at 2 = 2 6. 3 9 ∘ with a corresponding interplanar distance ( d hkl ) of 3.3754 Å and a crystallite size of 18 nm. XRD statistics indicated that the crystal structure of the original graphene was preserved. The crystalline structure was recovered and the interplaner distance was decreased following the high temperature thermal reduction. According to Raman spectroscopy, the impurity degree (I D /I G) region fraction of pristine graphene was 0.211. This indicates that the original graph produced by the current method has little distortion. Raman analysis shows that there is a linear red shift in peaks D-band (D), G-band (G), and second order of the D-band (2D) due to the increase in phonon–phonon nonlinear interactions with increasing temperature, so that peaks (D), (G) and (2D) shifts are shown. The majority of the functional groups were discovered to be eliminated after high temperature thermal treatment. The three-dimensional graphene sheet is highly defined and intricately coupled in the microstructure analysis, resulting in a laxer and porous structure. When treated at a temperature below 800 ∘ C, there was only minor damage to the reduced graphene oxide (RGO) microstructure. The results of the Atom Force Microscope (AFM) demonstrated that the flaws spread over time from the layer boundaries and pores to the edges and eventually resulted in a separate RGO archipelago. According to TGA analysis, at temperatures up to 800 ∘ C, the RGO sheet loses up to 45% of its weight. In this research, an electrochemical technique followed by a thermal reduction has been used to try to synthesize RGO. The structural disarray was seen to be lessening as a result of the heat treatment, and the RGO's crystal structure was restored to its former configuration. The results of the FTIR and TGA tests demonstrate that the bulk of the oxygen-containing functionalities were destroyed during the thermal reduction process. [ABSTRACT FROM AUTHOR]

A ZnCr-LDH@g-CN composite was synthesized through a one-pot hydrothermal method to fabricate an effective sensor for detecting vanillin. The prepared material was investigated by using structural and physical studies. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) with applied potential (Epa = + 0.68 V vs Ag/AgCl) were used to examine the electrochemical behavior of vanillin. The fabricated electrode exhibited a linear detection range of 0.001–143.2 μM, a low detection limit of 0.9 nM, sensitivity of 4.72 µA µM−1 cm−2, selectivity, stability, reproducibility (RSD = 4.40%), and repeatability (RSD = 4.46%). The optimized sensor was successfully applied to detect vanillin in real samples, including ice cream, chocolate, and water, and their recovery was 98.46–99.80%. Overall, the ZnCr-LDH@g-CN composite sensor offers a promising solution for precise vanillin detection. [ABSTRACT FROM AUTHOR]

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Foodborne illnesses can be infectious and dangerous, and most of them are caused by bacteria. Some common food-related bacteria species exist widely in nature and pose a serious threat to both humans and animals; they can cause poisoning, diseases, disabilities and even death. Rapid, reliable and cost-effective methods for bacterial detection are of paramount importance in food safety and environmental monitoring. Polymerase chain reaction (PCR), lateral flow immunochromatographic assay (LFIA) and electrochemical methods have been widely used in food safety and environmental monitoring. In this paper, the recent developments (2013–2023) covering PCR, LFIA and electrochemical methods for various bacterial species (Salmonella, Listeria, Campylobacter, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli)), considering different food sample types, analytical performances and the reported limit of detection (LOD), are discussed. It was found that the bacteria species and food sample type contributed significantly to the analytical performance and LOD. Detection via LFIA has a higher average LOD (24 CFU/mL) than detection via electrochemical methods (12 CFU/mL) and PCR (6 CFU/mL). Salmonella and E. coli in the Pseudomonadota domain usually have low LODs. LODs are usually lower for detection in fish and eggs. Gold and iron nanoparticles were the most studied in the reported articles for LFIA, and average LODs were 26 CFU/mL and 12 CFU/mL, respectively. The electrochemical method revealed that the average LOD was highest for cyclic voltammetry (CV) at 18 CFU/mL, followed by electrochemical impedance spectroscopy (EIS) at 12 CFU/mL and differential pulse voltammetry (DPV) at 8 CFU/mL. LOD usually decreases when the sample number increases until it remains unchanged. Exponential relations (R2 > 0.95) between LODs of Listeria in milk via LFIA and via the electrochemical method with sample numbers have been obtained. Finally, the review discusses challenges and future perspectives (including the role of nanomaterials/advanced materials) to improve analytical performance for bacterial detection.

Because of the quick growth of electrical instruments used in noxious gas detection, the importance of gas sensors has increased. X-ray diffraction (XRD) can be used to examine the crystal phase structure of sensing materials, which affects the properties of gas sensing. This contributes to the study of the effect of electrochemical synthesis of titanium dioxide (TiO2) materials with various crystal phase shapes, such as rutile TiO2 (R-TiO2NTs) and anatase TiO2 (A-TiO2NTs). In this work, we have studied the effect of voltage on preparing TiO2 nanotube arrays via the anodization technique for gas sensor applications. The results acquired from XRD, energy dispersion spectroscopy (EDX), and field emission scanning electron microscopy (FE-SEM) elucidate that TiO2 was created. In addition, systematically examining the gas detection properties was also done. The gas sensor was produced from TiO2 nanotubes, and the gas-detecting features were directed at nitrogen dioxide (NO2), which is a hazardous gas. The sensor formed from TiO2 nanotubes detects NO2 gas at various temperatures, from room temperature to 300 oC, and it has good sensitivity to this gas. The results exhibit that the gas sensor that was synthesized at 30 V has good sensitivity and a short response time at room temperature for NO2 gas sensing.

Antioxidants are very beneficial for health as they protect the body from the effects of free radicals on various degenerative diseases caused by food contamination, air pollution, sunlight, etc. In general, methods for measuring the capacity of antioxidants generally use accurate methods such as spectrophotometry and chromatography. Still, this takes time, accurate sample preparation, and must be performed in a laboratory with particular expertise. Therefore, a new, more practical method needs to be developed for determining antioxidants, namely the electrochemical method. The electrochemical method is a promising method to develop because it comes with several advantages, including high sensitivity and fast response. The electrochemical method discussed in this article reviews sensors, biosensors, and nanosensors. This paper comprehensively analyzes contemporary developments in electrochemical biosensor techniques and antioxidant evaluation methodologies. The discussion centers on utilizing multiple biosensors. Electrochemical biosensors have been determined to be prevalent in analyzing food quality, assessing active factor functionality, and screening practical components. The present study outlines the difficulties linked with electrochemical bio-sensor technology and provides insights into the potential avenues for future research in this domain. [ABSTRACT FROM AUTHOR]

This paper presents a novel electrochemical transduction method for the rapid and straightforward detection of bacterial biofilm. Briefly, fifteen isolates from various sources were collected and evaluated for their ability to generate biofilm. The Congo red-based agar method and the tube test were used for preliminary screening. A microtiter experiment was also performed to quantitatively examine the screening results and validate the outcomes of the proposed methylene blue-based electrochemical detection method. Electrochemical sensing was performed on the two selected isolates using methylene blue as a redox indicator. For optimization goals, several methylene blue concentrations were studied. Methylene blue at a concentration of 0.4 mM was used for the analysis conclusion. The developed electrochemical method displayed a linear R2 value of 0.9747. The new electrochemical approach demonstrated great sensitivity and rapid response compared to conventional microtiter test methods. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (Ag NPs) were quick synthesized by electrochemical method combined with heat treatment using silver electrodes and trisodiumcitrate (TSC) as reducing agent. This method is highly productive, with simple equipment, which is easily deployed on an industrial scale. The size of the Ag NPs is controlled through the amperage and the concentration of TSC. The effect of the synthesis’ conditions on optical properties of Ag NPs was surveyed. The Ag NPs were used to fabricate the Ag NPs-coated nonwoven fabrics. The bactericidal testing showed that Ag NPs-coated nonwoven fabrics were able to kill over 80% of E. coli and 96.9% of B. subtilis bacteria. These results can be considered as a new choice to prevent the spread of diseases caused by bacteria and viruses, thereby contributing to the protection of human health. [ABSTRACT FROM AUTHOR]

Fractal nanostructures have sharp tips and edges, and the gap between each trunk and branch is narrow. The structure is ideal for generating high-density plasmonic "hot spots" to achieve a high-intensity local electromagnetic (EM) field, which is beneficial for improving the substrate Raman activity. In this paper, an electrochemical method is used to prepare a silver fractal nanostructure substrate. A single layer of graphene is transferred to the surface of the silver fractal structure substrate by a wet chemical transfer method to prepare a graphene/metal (G/silver fractal) nanostructure composite substrate. Experimental observations show that G/silver fractal nanostructures exhibit higher Raman activity than that of pure silver fractal nanostructures. Numerical simulation calculation also verifies the accuracy of the experiment. In addition, the diversity of substrate detection is analyzed, and the experimental results show that the substrate can detect Rh6G and CV probe molecules simultaneously, which provides an experimental basis for investigating multichannel Raman spectroscopy sensing substrates. Therefore, the fabricated G/silver fractal nanostructure substrate provides substrate support and an experimental basis for Raman spectroscopy detection in several fields, including actual environment detection and biomedical vibration. [ABSTRACT FROM AUTHOR]

The structures of the solar-thermal membranes always influence the performance of light absorption and salt resistance in desalination. Inspired by the hierarchical structure of the coniferous leaves with excellent sunlight absorption in frigid regions, a coniferous leaf-like nickel black (L-Ni) membrane for desalination by solar-thermal energy conversion was prepared through electroplating method under a constant voltage. The light trapping effect of coniferous leaf-like structure led to the light absorption enhanced to 92%, the evaporation rate improved to 1.38 kg·m−2·h−1, and the solar-vapor conversion efficiency of L-Ni membrane reaching up to 89.75% under 1 sun irradiation. The stability of the membrane was still excellent after 20 cycles desalination because the coniferous leaf-like structure could enhance the hydrophobicity (water contact angle: 152°) of the L-Ni membrane, and it was beneficial to salt resistance. The promising performance of L-Ni membrane with coniferous leaf-like structure provides a possibility to replace the noble metal solar-thermal conversion materials. [ABSTRACT FROM AUTHOR]

In order to slow down the corrosion of oil transmission station in high salinity environment, the corrosion inhibition effect of four compound corrosion inhibitors on L360 steel in simulated deposit water at the bottom of tank was studied by static weight loss method, dynamic potential polarization curve, electrochemical impedance spectroscopy and metallographic microscope. Results showed that at 50 ℃, these four corrosion inhibitors could all inhibit the corrosion of L360 steel. And when the temperature was increased, the corrosion inhibition efficiencies of corrosion inhibitor 2 and 4 were both higher than 90%, meanwhile, the corrosion inhibition efficiency was less affected by the pressure and rotation speed. The four corrosion inhibitors were all mixed corrosion inhibitors which could inhibit both anode and cathode reactions. According to the Arrhenius formula, it was found that the slopes of the corrosion inhibitor 1 and 3 were changed, indicating that the two corrosion inhibitors were more affected by temperature, while the corrosion inhibitor 2 and 4 were less affected by temperature.

The influence of vibration mixing of an electrolyte based on a Watts bath with the addition of 50 g/L submicron-sized SiC powder on the composition and properties of coatings is investigated. The application of vibration to a suspension with the submicron-sized powder is shown to eliminate sedimentation phenomena and makes it possible to form composite coatings with a high volume fraction of SiC. The influence of the vibration frequency and amplitude is determined, and the optimum parameters, which make it possible to form coatings with a microhardness of 720 HV, are found. [ABSTRACT FROM AUTHOR]

Generally, our ecosystem is continuously contaminated as a result of anthropogenic activities that form the basis of our comfort in our routine life. Thus, most scientists are engaged in the development of new technologies that can be used in environmental remediation. Herein, highly calcined binary metal oxide (Er2O3@NiO) semiconductor nanocomposite (NC) was synthesized using a classical wet chemical process with the intention to both detect and degrade the toxic chemicals in an aqueous medium using a novel electrochemical current–potential (I–V) approach for the first time. Optical, morphological, and structural properties of the newly synthesized semiconductor NC were also studied in detail using FT-IR, UV/Vis., FESEM-EDS, XPS, BET, EIS, and XRD techniques. Then, a modified glassy carbon electrode (GCE) based on the newly synthesized semiconductor nanocomposite (Er2O3@NiO-NC/Nafion/GCE) as a selective electrochemical sensor was fabricated with the help of 5% ethanolic-Nafion as the conducting polymer binder in order to both detect and electro-hydrolyze toxic chemicals in an aqueous medium. Comparative study showed that this newly developed Er2O3@NiO-NC/Nafion/GCE was found to be very selective against m-tolyl hydrazine (m-Tolyl HDZN) and to have good affinity in the presence of other interfering toxic chemicals. Analytical parameters were also studied in this approach to optimize the newly designed Er2O3@NiO-NC/Nafion/GCE as an efficient and selective m-Tolyl HDZN sensor. Its limit of detection (LOD) at an SNR of 3 was calculated as 0.066 pM over the linear dynamic range (LDR) of our target analyte concentration (0.1 pM–0.1 mM). The limit of quantification (LOQ) and sensitivity were also calculated as 0.22 pM and 14.50 µAµM−1cm−2, respectively. m-Tolyl HDZN is among the toxic chemicals in our ecosystem that have lethal effects in living beings. Therefore, this newly designed electrochemical sensor based on semiconductor nanostructure material offers, for the first time, a cost-effective technique, in addition to long-term stability, that can be used as an alternative for efficiently probing other toxic chemicals in real samples. [ABSTRACT FROM AUTHOR]

Heavy metal ions, one of the major pollutants in the environment, exhibit non-degradable and bio-chain accumulation characteristics, seriously damage the environment, and threaten human health. Traditional heavy metal ion detection methods often require complex and expensive instruments, professional operation, tedious sample preparation, high requirements for laboratory conditions, and operator professionalism, and they cannot be widely used in the field for real-time and rapid detection. Therefore, developing portable, highly sensitive, selective, and economical sensors is necessary for the detection of toxic metal ions in the field. This paper presents portable sensing based on optical and electrochemical methods for the in situ detection of trace heavy metal ions. Progress in research on portable sensor devices based on fluorescence, colorimetric, portable surface Raman enhancement, plasmon resonance, and various electrical parameter analysis principles is highlighted, and the characteristics of the detection limits, linear detection ranges, and stability of the various sensing methods are analyzed. Accordingly, this review provides a reference for the design of portable heavy metal ion sensing. [ABSTRACT FROM AUTHOR]

Xanthine is a significant biomolecule and its concentration level in urine and blood plasma is an indicator of specified pathological states. Here, a new sensing platform was designed, which showed excellent analytical performance for xanthine. Importantly, it is the first time to investigate the kinetics of xanthine metabolic reaction by electrochemical method. The results demonstrated that the conversion of xanthine to uric acid completely conformed to the Michaelis‐Menten kinetics. Furthermore, we also studied the inhibitory effect of febuxostat on xanthine oxidase activity detailed. As expected, the work may offer potential value for researchers in the treatment of hyperuricemia and gout. [ABSTRACT FROM AUTHOR]

Selective electrochemical detection of berberine in biological fluids is challenging due to the high overpotential for berberine electrooxidation (＞1. 1 V vs. Ag/AgCl). By taking advantage of the non-covalent interactions between bromothymol blue （BTB) and berberine, and the reversible and low-potential electrochemical redox properties of polymerized BTB (poly-BTB), we report a new electrochemical method for berberine detection using poly-BTB as both the recognition unit for berberine and electrochemical probe, in which poly BTB is generated by electropolymerization of BTB immobilized onto the GC electrode surface via single-walled carbon nanotubes (SWNTs) . The strong affinity of poly-BTB toward berberine leads to the binding of berberine onto the electrode surface and consequently causes the decrement in the peak current of poly-BTB/SWNTsmodified electrode upon berberine being introduced, which validates berberine detection using the current decrease of the poly-BTB/SWNTs/GC electrode as the signal readout. Under the optimized conditions, the method shows linear concentration of berberine in the range of 0. 05~1 μmol/L and 1~100 μmol/L with a detection limit of 0. 022 μmol/L based on 3σ. As for the animal experiments, the electrochemical method has been demonstrated to be selective and effective for berberine level qualification in rat plasma and liver homogenates. This study offers a facile electrochemical method for berberine detection in biological fluids with less technical demanding and simple operating procedures, which holds a great promise for more applications in physiological and pathological researches associated with berberine. [ABSTRACT FROM AUTHOR]

Dissolved oxygen in vegetable oils is an important component of oil degradation over time. Various methods for the determination of dissolved oxygen in oils are proposed in the literature leading to very variable results. An amperometric method associated with a cell of measurement in dynamic mode makes it possible to determine the conditions of stability of the measurements of the relative dissolved oxygen concentration (RDOC, mg L−1) and the electrolysis current intensity (ECI) (nA) in seed oils and virgin olive oils. The effects of oxygenation/deoxygenation time and temperature on RDOC measurements are investigated. For virgin olive oils, the RDOC in bottles closed for eight weeks varies from 0 to 0.9 mg L−1. The nature of the fruitiness and the filtration of the oils have no influence on the RDOC. The monitoring of RDOC and ECI during the flow of virgin olive oil in a column open to air, simulating an industrial tank, shows differences in dissolved oxygen concentration due to a faster flow of oil in the center of the column than at the walls. This result is validated by a similar experiment with nitrogen inerting the column and by a numerical simulation. Practical applications: Knowledge of the oxygen dissolved in vegetable oils is an important factor in limiting the autoxidation phenomenon to increase their shelf life. The development of a cell for measuring the relative dissolved oxygen concentration (RDOC) in vegetable oils and its conditions of use, provides a tool for the RDOC applicable to the different stages of the manufacturing process and during storage or packaging. The RDOC measurement is particularly useful during long storage in tanks whether inerted or not. [ABSTRACT FROM AUTHOR]