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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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

In order to prepare fiber-type nanohybrid composites for electrochemical and antimicrobial applications, polypyrrole was combined with carboxymethylcellulose and multiwalled carbon nanotubes (PPy/CMC/MWCNTS). These composite materials were synthesized using ultrasonication and in situ polymerization. By using analytical methods, the structure and morphology of the synthesized nanohybrid composite material were confirmed. Slurry of fiber-type PPY/CMC/MWCNT composites synthesized in ethanol was deposited as a thin-uniform layer with conductive nafion (5% ethanolic solution of nafion) binder. Based on electrochemical measurements in a phosphate buffer medium, Sb3+ ions have linear responses between 0.1 nM and 0.01 mM, which is known as linear dynamic range (LDR). A sensor's sensitivity (22.4304 µAµM−1cm−2) is calculated using the LDR slope by considering the GCE surface area (0.0316 cm2). A signal-to-noise ratio of 3 is used to estimate the lower limit of detection which is equal to 96.82 ± 4.84 pM. Moreover, the antibacterial activity of the obtained polypyrrole/carboxymethylcellulose/MWCNT composite has also been evaluated "against Gram-positive bacteria B. subtilis along with S. aureus, as well as Gram-negative bacteria, P. aeruginosa along with Escherichia coli by utilizing" autoclave of agar media. In electrochemical analysis, the proposed Sb3+ cationic sensor exhibits appreciable reproducibility, response time, stability, and outstanding outcome in analysis of real samples. In the field of metal ion sensor, this reliable method might be prospective in the recent future. [ABSTRACT FROM AUTHOR]

In this work, the bacteria suspended in solution or immobilized in the biofilm were employed to study whether bacterial electrochemistry can reflect the impacts of the antibiotic residues in water on microorganisms. In the sensing system with immobilized bacteria, the tested antibiotics of 10∼40 mg/L showed an opportunity to inhibit respiration over a short time and the combined effect of these antibiotics exhibited a complex dose‐dependence. The resistance was induced for the immobilized bacteria in the repeated measurement over a long‐term period, which was fortunately solved by refreshing the biofilm via a nutrient supplementation. In the solution system, bacterial respirations were promoted by the tested antibiotics even at concentrations up to 160 mg/L, but β‐glucosidase activity was inhibited by only 0.05 mg/L antibiotic. Cu2+ and Zn2+ were further inducted in the suspended system, and the combination of metals and antibiotics showed an obvious antagonistic effect. Real water detection indicated that the bacterial electrochemical method was expected to warn the water qualities with a sudden change by an appropriate testing condition. [ABSTRACT FROM AUTHOR]

An applied electrochemical method in the form of a chronocoulometry technique is proposed for measuring Fick's diffusion constant of a thin protective coating layer over the conductive base materials. Using this method, the capacitance is monitored for a capacitor formed using the base material, an electrolyte such as aqueous NaCl, and an insulating coating layer in between. The capacitance increases when the distance between the base material and the electrolyte decreases in the diffusion of the electrolyte through the insulating coating layer. Therefore, the change in the capacitance provides a diffusion rate related to Fick's diffusion constant. Conventional gravimetric methods require a long measurement time to reach saturation, and thin coating layers of minimal weight increment through water diffusion were demonstrated to be inadequate for the methods. However, the new electrochemical method is appropriate for thin coating layers and requires a limited duration after the onset of diffusion. Experimental for 1-mm thick PA6 films provided Fick's diffusion constants of safer side with the new method of 15h by reflecting the heterogeneous properties of the surface, while the conventional gravimetric method in 360h provided smaller or danger-side values. [ABSTRACT FROM AUTHOR]

This study investigates the theoretical aspects of mass transport at the surface of a twin semicircular electrodiffusion probe tailored to measure the magnitude and direction of near-wall fluid flows. A critical aspect of this research is the development of a theoretical framework that facilitates experimental measurements by analytically relating measured electric currents to the wall shear stress vector. Central to the study is the derivation of analytical expressions for the mass transfer coefficients of the front and rear segments of the probe, which are essential for quantifying near-wall hydrodynamics. Validation of these analytical relations is achieved through numerical solutions of the convection–diffusion equation, providing a robust confirmation of the underlying theory. A comprehensive procedure for experimental data processing is proposed, taking into account both frontal and reverse flow conditions across the probe. In addition, a sensitivity analysis of the twin semicircular probe is performed. This analysis focuses on the response of current ratios to changes in the flow direction, an aspect critical to understanding the operational performance of the probe. The results of this analysis are compared to the characteristics of two-segment strip probes, highlighting the distinct sensitivity nuances of the twin semicircular probe. Our findings provide insight into the optimal application of this probe in various fluid dynamics scenarios. [Display omitted] • A new theory for twin semicircular electrodiffusion probes is presented. • Equally sized front and rear semicircular segments are studied. • Relations for mass transfer coefficients under arbitrary flow directions are derived. • A methodology for wall shear rate determination from experimental data is proposed. • The sensitivity of the probe to changes in inflow angle is analyzed. [ABSTRACT FROM AUTHOR]

This study validates the step potential electrochemical spectroscopy (SPECS) method and refines the associated analysis for differentiating the contributions of electrical double layer (EDL) formation and Faradaic reactions to the total charge storage in three-dimensional porous pseudocapacitive electrodes. The modified Poisson–Nernst–Planck (MPNP) model coupled with the Frumkin–Butler–Volmer theory were used to numerically reproduce experimental data obtained from the SPECS method accounting for interfacial, transport, and electrochemical phenomena in porous electrodes consisting of monodisperse spherical nanoparticles ordered in face-centered cubic (FCC) packing. The fitting analysis of the SPECS method was modified for the Faradaic current. The new model can accurately predict the individual contributions of EDL formation and Faradaic reactions to the total current. Moreover, the contributions of EDL formation at the electrode surface or at the electrode/electrolyte interface within the porous electrode can be identified. Similarly, the Faradaic reactions due to surface-controlled or diffusion-controlled mechanisms can be distinguished. Furthermore, the capacitance associated with EDL formation obtained from SPECS was in good agreement with that obtained from cyclic voltammetry. Finally, cyclic voltammograms were reconstructed using the multiple potential step chronoamperometry (MUSCA) method, and the integral capacitance associated with each charge storage mechanism was calculated for a range of scan rates. [Display omitted] • SPECS and MUSCA methods were reproduced numerically using continuum modeling. • SPECS fitting was modified for Faradaic current limited by kinetics or diffusion. • Modified analysis was validated numerically in 3D porous pseudocapacitive electrodes. • It can identify contributions of surface-controlled or diffusion-controlled reactions. • It can distinguish EDL formation at electrode surface or within the porous structure. [ABSTRACT FROM AUTHOR]

TEM images for the Carbon Black − CB (a), Palladium nanoparticles entrapped in aluminum hydroxide − PdNPAH (b), PdNPAH at 20 nm (c) and PdNPAH/CB (d). [Display omitted] • Exploiting carbon black and palladium nanoparticles entrapped in aluminum hydroxide matrix. • A novel and low cost electrochemical method for the detection of BHA antioxidant. • Selective method for detection of BHA even in presence of BHT and TBHQ. • The method was successfully applied for BHA in biofuel samples. A simple and selective method for determination of 2(3)- t -Butyl-4-hydroxyanisole (BHA) based on carbon black (CB) paste electrode modified with Palladium nanoparticles entrapped in aluminum hydroxide matrix (PdNPAH) is described for the first time. The materials were characterized by Fourier-Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The composition of the paste was studied using different amounts of each material. The voltammetric studies of the behavior of BHA on PdNPAH/CBP electrode demonstrated a catalytic activity for the oxidation process of BHA. Also, the voltammetric studies showed that it is possible to determine BHA in presence of 3,5-Di- tert -butyl-4-hydroxytoluene (BHT) and 2-(1,1-Dimethylethyl)-1,4-benzenediol (TBHQ). Under optimized conditions, the method showed a linear response for BHA from 1-5000 µmol/L and a detection limit of 0.20 µmol/L. The proposed method presented good selectivity, precision and it was successfully applied for detection of BHA in biofuel with recovery values from 98.80 % to 105.29 %, showing a good accuracy for the proposed method. [ABSTRACT FROM AUTHOR]

In Sri Lanka wastewater originated from prawn-farms contain an excessive amount of nitrate that is becoming a crucial issue on human health and environment. Currently, there are no proper practices to treat the wastewater. This study was aimed to develop an electrochemical method to remove nitrate from the wastewater and to investigate the effect of pH, retention time (RT), current, and surface area (SA) of the electrodes using Taguchi method. The maximum removal efficiency of nitrate (72%) by using copper cathode was obtained and the removal efficiency rates with copper cathode were higher than that with carbon and aluminum cathode. [ABSTRACT FROM AUTHOR]

A "signal-on" dual-mode aptasensor based on photoelectrochemical (PEC) and electrochemical (EC) signals was established for kanamycin (Kana) assay by using a novel Z-scheme AgBr/AgI-Ag-CNTs composite as sensing platform, an aptamer structure switch, and K3[Fe(CN)6] as photoelectron acceptor and electrochemical signal indicator. The aptamer structure switch was designed to obtain a "signal-off" state, which included an extended Kana aptamer (APT), one immobilized probe (P1), and one blocking probe (P2) covalently linked with graphdiyne oxide (GDYO) nanosheets. P1, P2, and aptamer formed the double helix structure, which resulted in the inhibited photocurrent intensity because of the weak conductivity of double helix layer and serious electrostatic repulsion of GDYO towards K3[Fe(CN)6]. In the presence of Kana, APT specifically bound to the target and dissociated from P1 and P2, and thus, a "signal-on" state was initiated by releasing P2-GDYO from the platform. Based on the sensing platform and the aptamer structure switch, the dual-mode aptasensor realized the linear determination ranges of 1.0 pM–2.0 μM with a detection limit (LOD) of 0.4 pM (for PEC method) and 10 pM–5.0 μM with a LOD of 5 pM (for EC method). The aptasensor displayed good application potential for Kana test in real samples. [ABSTRACT FROM AUTHOR]

In this paper, an electrochemical method was proposed to recycle nanoarchitectonics of graphene oxide (GO) from carbon fiber reinforced polymer (CFRP). In the recycling process, NaCl solution with varied concentrations (3% and 10%) and tap water were used as electrolyte, while the impressed current density varied from 2.67 A/m2 to 20.63 A/m2. The results indicated that in NaCl electrolyte, the obtained nanoarchitectonics of GO contained a large amount of nano-carbon onions (NCO) produced by etching CFRP, while high purity GO was produced when tap water was used as electrolyte. The higher current density improved the production efficiency and resulted in a finer GO particle size. The proposed recycling method of GO is economical and simple to operate. It also provides an alternate approach to handle discarded CFRP. [ABSTRACT FROM AUTHOR]

Breast cancer is the most common malignant tumor in women, its incidence is secret, and more than half of the patients are diagnosed in the middle and advanced stages, so it is necessary to develop simple and efficient detection methods for breast cancer diagnosis to improve the survival rate and quality of life of breast cancer patients. Exosomes are extracellular vesicles secreted by all kinds of living cells, and play an important role in the occurrence and development of breast cancer and the formation of the tumor microenvironment. Exosomes, as biomarkers, are an important part of breast cancer fluid biopsy and have become ideal targets for the early diagnosis, curative effect evaluation, and clinical treatment of breast cancer. In this paper, several traditional exosome detection methods, including differential centrifugation and immunoaffinity capture, were summarized, focusing on the latest research progress in breast cancer exosome detection. It was summarized from the aspects of optics, electrochemistry, electrochemiluminescence and other aspects. This review is expected to provide valuable guidance for exosome detection of clinical breast cancer and the establishment of more reliable, efficient, simple and innovative methods for exosome detection of breast cancer in the future. [ABSTRACT FROM AUTHOR]

The corrosion resistance of crystalline zero valent metal in aqueous solution is generally poor, thus a large part of zero valent metal will be corroded by water during the degradation and the reactivity slows down quickly. To address this problem, this paper adopted Al-based amorphous alloys as catalysts in combination with electrochemical methods to achieve efficient degradation of wastewater, used single roll strip casting method to make Al86Ni10Y4 amorphous ribbons, and used electrochemical method with Al86Ni10Y4 amorphous alloy as anode and graphite as cathode to study the degradation ability of direct blue dye under different external conditions. The results showed that when pH value was 3 and current density was 6.1 mA/cm², the decolorization rate reached 95.22% in 20 min. Al based amorphous alloys can be used for the treatment of alkaline azo dye solutions, which has better corrosion resistance than corresponding crystalline alloy and is more difficult to lose electrons. They hold promising application potential in degrading azo dye solutions. [ABSTRACT FROM AUTHOR]

The author has focused on the corrosive effect of 0.14% carbon steel in the occurrence of several amounts of soluble Sulfonated Polystyrene (SPS) and was found to be best efficient on soft iron exterior at 100ppm concentration in 0.5M hydrochloric acid assortment at 298K heat during 3h of time in this paper. The examination was performed by studying the weight loss of mild steel by varying different parameters like mixture concentration, time, and solution temperature. The efficiency of SPS was observed to rise with an increase of 91.90% of an inhibitor in the acid solution. The mechanism of physical adsorption was studied to the initiation and permitted dynamics for the reaction of altitude and extracted taking place towards the exterior of the iron sample in endothermic, impulsive and dependable through the Langmuir isotherm adsorption. Anodic and cathodic both type of nature of soluble SPS was studied using the potentiodynamic polarization method. The AFM analysis was used to do the surface and protective film analysis and under varied settings, SPS polymer inhibitor proven to be more suited for iron metal exterior [ABSTRACT FROM AUTHOR]

Silver (Ag) ‐ doped ZnO nanoparticles (0 % to 20 %) were synthesized by the microwave method. The structural, optical, and electrochemical properties were observed through Transmission Electron Microscopy (TEM), X‐ray Diffraction (XRD), Energy Dispersive X‐ray (EDX), UV‐Visible spectroscopy, Photoluminescence, and Cyclic‐Voltammetry (C−V) techniques. The platinum metal counter electrode was replaced by using dip coating, spin coating, and electrochemical method electrodes. The best current‐voltage performance was exhibited by the 5 % Ag‐doped ZnO DSSCs constructed by the electrochemical method counter electrode with a conversion efficiency (η) of 6.19 %, open‐circuit voltage (Voc) of 0.58 V, short circuit current density (Jsc) of 19.12 mA/cm2 and fill factor of 55.08 %. This performance is superior to the counter electrodes made from the spin coating (1.45 %) and dip coating (0.91 %). The higher catalytic behavior of the electrochemical method counter electrode and appearing plasmons peaks in all Ag‐doped ZnO nanoparticles influence the enhancement of current density and overall conversion efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hierarchical flower-like nanosheets are electrodeposited on stainless-steel mesh (BiOI@ZnO@SSM). • The photocatalytic activity of BiOI@ZnO@SSM is significantly enhanced due to the formation of p-n heterojunction. • The BiOI@ZnO@SSM can remove the organic pollutants from wastewater while separating the oil-water emulsion. • The BiOI@ZnO@SSM displays excellent chemical/mechanical stability and recyclability. The emulsified oil wastewater produced from the petrochemical industries and people's daily life would cause severe harm to the ecological environment if improperly treated. Thus, the development of membranes with efficient oil–water separation and self-cleaning property remains a key global research direction. In this study, p-n heterojunctions membrane with BiOI@ZnO hierarchical flower-like-nanosheets structures (BiOI@ZnO@SSM) has been successfully fabricated through two-step electrodeposition method. The BiOI@ZnO@SSM is capable of separating water and oil from emulsified oil wastewater and performing efficient adsorption and photocatalytic degradation of organic pollutants in water. The separation efficiency of BiOI@ZnO@SSM for numerous oil-in-water (O/W) emulsions exceeded 99.3 % as well as a fast permission flux up to 299.8 L·m−2·h−1. And the degradation efficiency of BiOI@ZnO@SSM for Rhodamine B (RhB) can reach to 99.0 % in 80 min under visible-light irradiation, which is 1.5 times as high as that of ZnO@SSM. The obviously enhanced photocatalytic activity of BiOI@ZnO@SSM is due to the formation of p-n heterojunction between p-type BiOI and n-type ZnO, which broadens the light absorption range, promotes the effective separation and prolongs the lifetime of electron and hole pair and realizes efficient degradation of organic pollutants. Meanwhile, multidimensional and hierarchical nanoflowers structure is not only helpful to improve the utilization of light, but also can increase more catalytic active sites. After ten cycles, this membrane maintained high emulsion separation efficiency of 99.6 % and the photodegradation efficiency remained above 94.5 %, demonstrating its good recyclability and stability. This durable and multifunctional heterojunction composite membrane with a flower-like structure is of great application potential in dealing with practically emulsified wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrochemical degradation TBP by a Ti/SnO 2 -Sb/F-PbO 2 electrode was proposed. • Removal was achieved of 82.4 % in 80 min with an energy efficiency of 82.6 g kWh−1. • A possible mechanism for the electrochemically degradation of TBP was provided. • Three kinds of degradation behaviors were observed. A Ti/SnO 2 -Sb/F-PbO 2 electrode was applied to electrochemically oxidize tributyl phosphate (TBP). Under the optimal conditions, TBP removal reached 82.4 % in 80 min with an energy efficiency of 82.6 g kWh−1. This method overcame some TBP biodegradation's flaws such as narrow initial treating concentrations range and time- consuming. The degradation energy efficiency of our method ranges from 34.4 g kWh−1 to 379 g kWh−1 at different initial concentrations (0.5–5.0 g/L), which is also far higher than that of a previous electrochemical treatment of TBP (0.13 g kWh−1). [ABSTRACT FROM AUTHOR]

Carbon-based quantum dots, zero-dimensional carbon nanomaterials that can be widely used with a particle size of 1-10nm, can be widely used in fluorescent carbon nanomaterials in thousands of households. This article will first elaborate on carbon-based quantum dots and metal nanomaterials and explain the related methods of making them. First, the top-down method is used to prepare carbon quantum dots, the fluorescence mechanism of carbon-based quantum dots is used, and the electrochemical method is used at high temperature. Carbonization burning method and laser ablation method, the mixture of graphite powder and polyethylene glycol ester is hot pressed, baked, and cut in an argon atmosphere to obtain strong fluorescent carbon-based quantum dots, and then explain the immune algorithm to prepare nanocomposites for cermet mold materials, use the diversity of antibodies to calculate the concentration and quantity, and calculate its viability. Through regression coefficients, it can be shown that the immune algorithm is used to optimize the component optimization design of Ti(C,N)-based nanocomposite cermet mold materials. The effect is better. [ABSTRACT FROM AUTHOR]

An electrochemical detection of inositol content using platinum (Pt)-based noble metal electrode is investigated. In this work, the electrochemical behavior of the platinum electrode has been studied and analyzed using a three-electrode system against a silver–silver chloride (Ag/AgCl) reference electrode and a steel counter electrode. Differential pulse voltammetry technique has been employed for this experimental study. A satisfactory linear range of operation was obtained from 50 to 400 μ M with LOD = 1 9. 2 8 μ M. Electrochemical responses for several inositol concentrations 50, 80, 100, 200, 300 and 400 μ M have also been analyzed using principal component analysis (PCA) with effective data clustering. A good class separability index (SI) was found to be 142.91. In addition, a prediction estimation of inositol contents using partial least square regression (PLSR) and principal component regression (PCR) algorithms were also evaluated and prediction accuracies of 93.69% and 93.71% were obtained, respectively. Moreover, the application of the Pt electrode over real orange juice sample extracts revealed satisfactory recovery rate of 96.18%. Thus, this technique of electrochemical system may be subjected for inositol detection in our daily-life food (especially juice, beverages) consumption. [ABSTRACT FROM AUTHOR]

Drinking water containing nitrate ions at a higher concentration level of more than 10 mg/L, according to the World Health Organization (WHO), poses a considerable peril to humans. This danger lies in its reduction of nitrite ions. These ions cause methemoglobinemia during the oxidation of hemoglobin into methemoglobin. Many protocols can be applied to the remediation of nitrate ions from hydra solutions such as Zn metal and amino sulfonic acid. Furthermore, the electrochemical process is a potent protocol that is useful for this purpose. Designing varying parameters, such as the type of cathodic electrode (Sn, Al, Fe, Cu), the type of electrolyte, and its concentration, temperature, pH, and current density, can give the best conditions to eliminate the nitrate as a pollutant. Moreover, the use of accessible, functional, and inexpensive adsorbents such as granular ferric hydroxide, modified zeolite, rice chaff, chitosan, perlite, red mud, and activated carbon are considered a possible approach for nitrate removal. Additionally, biological denitrification is considered one of the most promising methodologies attributable to its outstanding performance. Among these powerful methods and materials exist zero-valent iron (ZVI), which is used effectively in the deletion process of nitrate ions. Non-precious synthesis pathways are utilized to reduce the Fe2+ or Fe3+ ions by borohydride to obtain ZVI. The structural and morphological characteristics of ZVI are elucidated using UV–Vis spectroscopy, zeta potential, XRD, FE-SEM, and TEM. The adsorptive properties are estimated through batch experiments, which are achieved to control the feasibility of ZVI as an adsorbent under the effects of Fe0 dose, concentration of NO3− ions, and pH. The obtained literature findings recommend that ZVI is an appropriate applicant adsorbent for the remediation of nitrate ions. [ABSTRACT FROM AUTHOR]

Zeolitic imidazolate frameworks (ZIFs) are widely used in recent times for catalysis and in biomolecules detection. Many neurotransmitters are associated with human body, and among them, serotonin (5-HT) (SER) plays a dynamic role in biological functions. Any alteration in its level leads to severe problems including death, so the monitoring SER is very much concerned. In this direction herein, we successfully synthesized nickel–iron-based ZIF (NiFe-ZIF) microfibers for demonstrating the sensing of neurotransmitter serotonin (SER). Further, the electrochemical behavior investigated by electrochemical studies ensures its high conductivity and sensing ability towards SER. Moreover, the SWV studies also exhibit wide linear range of 40 nM–30 µM with detection limit 3 nM confirming excellent platform role for biomedical applications. Moreover, the real-time application of the proposed sample was also investigated by serum with the exhibition of exceptional outcome of the proposed biosensor. Bi-metallic NiFe based ZIF MFs have been synthesized and successfully utilized for the first time as a biosensor for an effective detection of the neurotransmitter and hormone SER with very low detection limit. The designed sensor is also applicable for the real time analysis and can be further applicable for other device fabrications such as point of care devices like glucose sensors. [ABSTRACT FROM AUTHOR]

This article mainly reviews the research progress of electrochemical treatment of oily wastewater.Several most common electrochemical treatment methods such as electroflotation, electroflocculation, and electrocatalytic oxidation are discussed separately. Briefly describe the principle and application of electrochemical treatment methods; mainly introduce the application research of electrocatalytic oxidation method to treat oily wastewater, summarize the advantage of electrocatalytic oxidation treatment of wastewater; analyze the effect of electrode materials, current density, and electrolyte types on wastewater treatment impact. At the same time, the combined process of electrochemical method and other treatment methods and the development status and application prospects of three-dimensional electrochemical method for treating oily wastewater are discussed. Finally, the development trend and prospect of the electrochemical treatment of oily wastewater are prospected. [ABSTRACT FROM AUTHOR]

Exosomes, small vesicles with the diameters of 40–160 nm, play an important role in intercellular transport and communication. Exosomes are rich in many kinds of biomolecules, and differential expression of exosomal contents directly reflects the state of the original cells. Therefore, the tumor exosomes are appearing as promising biomarkers in liquid biopsy, and highly sensitive and specific detection of tumor exosomes may provide the information for the early diagnosis, real-time monitoring and treatment of the tumors. In this review, we summarized the recent advances in the detection of tumor exosomes, mainly focusing on the use of different analytical techniques, such as optical and electrochemical methods as well as that combination with newly-emerging microfluidic techniques, thereby providing valuable information for the application in the clinical diagnosis and management of the tumors. [ABSTRACT FROM AUTHOR]

Today, the reduction of fossil fuel resources and the increase of their destructive environmental effects are important challenges. One strategy to this problem is application of new sources of energy supply. Hydrogen can play an important role in future energy supplies due to its unique properties such as clean combustion and high energy content relative to mass. In addition, hydrogen is considered as a green energy because it can be produced from renewable sources and is not polluting. The most important issue in hydrogen as a fuel is its storage. Hydrogen must be stored reversibly in a completely safe manner as well as with high storage efficiencies. One of the best ways to store hydrogen is using of new nanostructured adsorbents. In this study, first strontium hexaferrite (SrFe 12 O 19) nanostructures are synthesized by sol-gel auto-combustion method. Then, the samples structure is studied using various techniques. Furthermore, the nanostructures are used as hydrogen storage materials. Using electrochemical techniques, the hydrogen storage properties of the materials are investigated in alkaline media. The obtained electrochemical results show that the maximum hydrogen storage capacity of SrFe 12 O 19 nanostructures is about 3100 mAh/g. • Synthesis of novel nano-structured based hexaferrite compounds. • Characterization studies using various microscopic and electrochemical techniques. • Significant electrochemical hydrogen storage capacity for SrFe 12 O 19 nanostructures. • Promising materials for electrochemical energy storage. [ABSTRACT FROM AUTHOR]

In an electrochemical reactor made by the authors, the degradation of simulated methyl orange wastewater was experimentally studied by using a diaphragm system with an anode and cathode coaction electrochemical method. Response surface methodology was used to optimize the one-factor test results. The optimum condition was that when the voltage was 20.56 V, the distance between the plates was 4.4 cm, and the aeration rate was 2.21 L/min. The order of influence of each factor was as follows: voltage> distance between electrodes> aeration rate. The two most influential factors were the voltage and aeration rate. Under optimal conditions, the decolorization rate of methyl orange in the cathode chamber reached 90.81%, and in the anode chamber, it was 98.75%. At the same time, the energy expenditure of the diaphragm system during electrolysis is analyzed. UV-visible absorption spectroscopy showed that methyl orange experienced both molecular structure degradation and mineralization during the electrolysis process. The decolorization effect in the anode chamber was better than that in the cathode chamber, but the degree of mineralization of methyl orange in the cathode chamber was better than that in the anode chamber. [ABSTRACT FROM AUTHOR]

Developing ultrasensitive and user-friendly methods for the detection glucose has attracted more and more attention. By virtue of high selectivity and sensitivity, enzyme-based glucose sensor plays a key role in point-of-care sensing technology for detecting glucose concentration. In this study, Amplex Red (AR), as both indicator and mediator, was investigated to detect glucose in presence of glucose oxidase (GOx) enzymes using colorimetric and electrochemical methods. Without using any advanced techniques and sophisticated nanomaterials, 1 μM glucose can be easily detected through simply detecting the solution color with a visual colorimetric method. On the other hand, the electrochemical method can provide much higher sensitivity for the detection of glucose, which achieves a linear range spanning from 20 nM to 3.56 μM with a limit of 7.3 nM (signal-to-noise ratio SNR = 3). It is also found that the presence of other sugars such as fructose, lactose, and maltose have very limited interference effects on the detection of glucose. More importantly, a bare GC electrode was used in all these electrochemical measurements without any electrode surface modification, guaranteeing a simple and fast operation. The analytical platforms for the detection of glucose presented here not only provide simple, fast, and ultrasensitive methods, but also have the potential to advance the sensing technology in the application of other health diagnostic research areas. [ABSTRACT FROM AUTHOR]

Generally, the ultraviolet photodetector devices based on ZnO/PEDOT composites were fabricated by spin coating of PEDOT solutions on ZnO nanorods array, which needs the polymer disperesed in solvent. In this paper, an electrochemical deposition method was proposed for the prepparation of ZnO/PEDOT‐type conducting polymers composites for ultraviolet photodetector. The poly(3,4‐proplene‐dioxythiophene) (PProDOT) and poly(3,4‐ethylenedioxy‐thiophene)(PEDOT) were selected as PEDOT‐type conducting polymers. The structure of composite materials was characterized by UV‐vis, XRD, Raman, SEM,EDS and XPS analysis. The effects of different polymers on the UV sensing ability of ZnO nanorods were studied. The structural results showed that the composites were successfully prepared by electrochemical deposition method indicating that the electrochecmial method was an effective way to prepraration of this type composites.The photoelectric performance test showed that the structure of the polymer chain affected the responsiveness of the materials, and the response time of ZnO/PProDOT was 14 s shorter than that of ZnO/PEDOT, and it displayed an excellent long‐term stability. After deposition of PProDOT, the UV responsivity of ZnO nanorods was increased from 2.5 A W−1 to 27.5 A W−1, and the external quantum efficiency and detectivity were significantly improved, implying that the PProDOT can be ideal candidate material for ultraviolet photodetector. [ABSTRACT FROM AUTHOR]