Specific Electrical Conductivity Research Articles

Diagnosis and treatment of patients with acute and chronic sinusitis using data from studies of physicochemical parameters of nasal secretions

Research and analysis of the physicochemical parameters of nasal secretions obtained in the production of the nasal tract are important in the treatment of various diseases. The influence of these parameters on the effective use of drugs is also essential. The acidity of the medium (pH), the density (r), and the viscosity (h) of the medium were determined and the specific electrical conductivity (c) was changed. The selected physicochemical parameters must provide certain values (varying within narrow limits) for the human body. Significant changes in the nature of these indicators are observed in various misconceptions. Based on the above aspects, it can be concluded that it is of great importance to study these parameters. Samples of nasal secretions were taken from people at different stages of their illness (at diagnosis, in the treatment process and after its completion). Samples from individuals with chronic and acute sinusitis were tested. Based on the obtained data, for the acidity of the medium, density, viscosity, and specific electrical conductivity, it could be concluded that all patients benefitted from nasal saline irrigation. After the therapy, the general parameters under study, reach values close to the physicochemical parameters. The results can be used as proper drug treatment or for improving the current drug studies.

Influence of the (E)-N-(4-diphenylamino)benzylidene)benzo[d]thiazol-2-imine on the dielectric properties of P3HT, PCBM and P3HT:PCBM system in a wide temperature and frequency range

We investigated the relaxation processes occurring in the sub-hertz frequency range, difficult to access in experiments, using unconventional method of analysing the dielectric relaxation spectra recorded for highly conductive donor–acceptor materials. In particular, we investigated how the dielectric properties of the conventionally used donor–acceptor P3HT:PCBM system will change when PCBM is replaced by a new acceptor, the imine SC2, or when the imine SC2 is added to this system. The dielectric studies in the broad frequency and temperature range were performed and the relaxation processes connected with the charge movements and with the dipolar rotation (β relaxation) in systems based on polymer P3HT were extracted from the spectra. The relaxation times as well as the activation energies were obtained. Also the temperature dependence of the DC specific electric conductivity and high frequency permittivity for all materials studied were determined as well as the static permittivity for the P3HT:SC2 system.

Recent Advances in Biodegradable Polymers and Their Biological Applications: A Brief Review.

The rising significance of the field of biopolymers has driven the rapid progress of this distinctive class of polymeric materials in the past decades. Biodegradable polymers have acquired much attention because they play an essential role in humans' lives due to their specific tunable electrical conductivity and biodegradability characteristics, making them fascinating in many applications. Herein, we debated the recent progress in developing biodegradable polymers and their applications. Initially, we introduce the basics of conducting and biodegradable polymers, trailed by debates about the effective strategies currently used to develop biopolymers. Special importance will focus on the uses of biodegradable polymers in drug delivery and tissue engineering, as well as wound healing, demonstrating the recent findings, and uses of several biodegradable polymers in modern biological uses. In this review, we have provided comprehensive viewpoints on the latest progress of the challenges and future prospects involving biodegradable polymers' advancement and commercial applications.

Electrochemical Performance of Potassium Hydroxide and Ammonia Activated Porous Nitrogen-Doped Carbon in Sodium-Ion Batteries and Supercapacitors

Carbon nanomaterials possessing a high specific surface area, electrical conductivity and chemical stability are promising electrode materials for alkali metal-ion batteries and supercapacitors. In this work, we study nitrogen-doped carbon (NC) obtained by chemical vapor deposition of acetonitrile over the pyrolysis product of calcium tartrate, and activated with a potassium hydroxide melt followed by hydrothermal treatment in an aqueous ammonia solution. Such a two-stage chemical modification leads to an increase in the specific surface area up to 1180 m2 g−1, due to the formation of nanopores 0.6–1.5 nm in size. According to a spectroscopic study, the pore edges are decorated with imine, amine, and amide groups. In sodium-ion batteries, the modified material mNC exhibits a stable reversible gravimetric capacity in the range of 252–160 mA h g−1 at current densities of 0.05–1.00 A g−1, which is higher than the corresponding capacity of 142–96 mA h g−1 for the initial NC sample. In supercapacitors, the mNC demonstrates the highest specific capacitance of 172 F g−1 and 151 F g−1 at 2 V s−1 in 1 M H2SO4 and 6 M KOH electrolytes, respectively. The improvement in the electrochemical performance of mNC is explained by the cumulative contribution of a developed pore structure, which ensures rapid diffusion of ions, and the presence of imine, amine, and amide groups, which enhance binding with sodium ions and react with protons or hydroxyl ions. These findings indicate that hydrogenated nitrogen functional groups grafted to the edges of graphitic domains are responsible for Na+ ion storage sites and surface redox reactions in acidic and alkaline electrolytes, making modified carbon a promising electrode material for electrochemical applications.

Study of the electrophysical characteristics of plastic lubricants

Actively developing electric automobile transport assumes the creation of conductive lubricants. We pres­ent a setup designed to study the electrophysical properties of industrially produced and model plastic lubricants, as well as the samples of a similar consistency. The setup operates within the current frequency range from 0.1 to 1 kHz and includes a temperature-controlled measuring cell that allows changes in the sample thickness and temperature in the range from 20 to 120 °C. A method for determination of cur­rent-voltage characteristics with subsequent calculation of the specific electrical conductivity is proposed. The specific electrical conductivity of model plastic lubricants based on medical vaseline added with car­bon nanostructures (few-layer graphite fragments and their modified analogs) was studied using the de­veloped setup. Vaseline was used as a base model lubricant, since its rheological properties are similar to that of plastic lubricants and it does not contain any additional additives that can affect the measurement result. The electrically conductive properties of the dispersions of carbon nanostructures and their modi­fied analogs in vaseline were analyzed. It is shown that the introduction of carbon nanostructures into dielectric vaseline turns it into an electrically conductive material. The developed setup makes it possible to study the specific electrical conductivity of systems simulating plastic lubricants with a sufficient accuracy. The results obtained can be used to improve the methodology for studying the specific electrical conductivity of model and industrially produced plastic lubricants, including those with conductive additives.

Nitrogen doped 2D-3D network structure CMN/NiO composite for high-performance hybrid supercapacitors

In order to reduce the dense stacking of NiO nanosheets to obtain higher capacity and energy density, using CNT@mSiO2@NC (CMN) nanotubes as the substrate and urea as the precipitant, porous NiO nanoflowers and nanosheets were successfully grown between CMN nanotubes (CMN/NiO) by solvothermal method to control the morphology. The N-doped porous CMN/NiO composite obtains a high reversible capacity of 529 F g−1 in 6 M KOH electrolyte, and the capacity cycling retention rate reach 119.84% after 5000 cycles of 20 A g−1. The characteristic mesh-flake/sheet structure and the synergistic effect between components fully expose the electrochemically active sites in CMN/NiO and improve it utilization during charging-discharging, and the N atom doping enhances the electrical conductivity of CMN/NiO. The assembled asymmetric supercapacitor has a voltage window of up to 2.0 V, and an energy density performance of 26.27 Wh kg−1 at a power density of 800 W kg−1. This special structural design improves the specific capacitance, electrical conductivity, energy density and cycling stability of the electrode material compared to NiO.

(Digital Presentation) Theoretical Investigation of the Structure and Physico-Chemical Properties of Alkali Metal Perchlorate Solutions in Sulfolan

Next-generation batteries based on Na and K, which are alkali metals common in the earth's crust are considered promising alternatives to lithium-ion batteries in future energy storage and storage systems.Sulfur-containing compounds, such as sulfolane and its derivatives, are currently considered as promising solvents for use in lithium and post-lithium-ion batteries. However, the properties of alkali metal salts solutions in sulfolane are poorly understood.The aim of our work was to study the physicochemical properties of solutions of alkali metal perchlorates in sulfolane and intermolecular interactions in solutions (cation-solvent molecules, cation-anion) using the molecular dynamics method.In our work we used the OPLSaa non-polarizable force field. The molar ratio of salt and solvent was 1:20 (~0.5 M) in solutions of ClO4 - salts of Li, Na, K in sulfolane (SL). The calculations were carried out in the same way as in the work 1.The results of calculating the physicochemical properties of MeClO4 solutions in SL are summarized in Table. The calculated density values of LiClO4/SL and NaClO4/SL systems differ from those measured experimentally 2,3 by less than 0.6% (Table). It can be assumed that the calculated value of the density of the KClO4/SL solution is also close to the measured value. The calculated values of the specific electrical conductivity of LiClO4/SL and NaClO4/SL exceed the experimentally measured values by 2.5 and 1.3 times, correspondently. The overestimated calculated values can be explained by a strong simplification of the Nernst–Einstein relation which takes into account only cations and anions motion, and doesn’t take into account the motion of ion associates.The calculated transfer numbers of cations in MeClO4/SL are about 0.4.There are two peaks on the RDF curves of SL oxygen atoms around Li+, Na+, K+ (g(O(SL)-Me)): the first – clearly narrow and the second – broadened (Figure). The difference between the positions of the peak maxima (0.23 nm) is comparable to the distance between oxygen atoms in the SL (0.256 nm). Thus, the second broadened peak in the g(O(SL)–Me) curves is due to the second oxygen atom of the same SL molecule. The probability of Me+ solvation by the first or second oxygen atom of SL is the same. This is confirmed by the coincidence of the integral curves N(O(SL)-Me) of SL oxygen atoms around Me+ (Figure).There is one narrow clear peak on the RDF curves of the sulfur atom of SL around the cation g(S(SL)-Me). The maximum position is shifted relative to the maximum position of the RDF Me-O by 0.14 nm. It is comparable to S-O bond length (0.13 nm)) (Figure). Thus, the cation interacts with one oxygen atom of SL while the second oxygen atom doesn’t participate in the cation solvation and is turned in the opposite direction from it.There are two peaks on the RDF curves of the oxygen atoms of the ClO4 - around the cation g(O(ClO4 -)-Me): the first - clearly narrow and the second - broadened. The location of the first peak relative to the cation corresponds to the first solvation shell of the cations (Figure 1). The height of the first peak is significantly lower than the height of the peak on g(O(SL)-Me) curve. This indicates a low probability of the ClO4 - entering the first solvation shell of cations under the studied conditions (MeClO4/SL = 1:20, 303 K, 1 atm). Preferably, the ClO4 - is located in the outer coordination sphere of the solvate complex.Coordination numbers (CN) of metal cations were calculated based on the integral curves of RDF. The sum of the CN for the oxygen atoms of SL corresponds to the calculated CN of cations for the sulfur atom of SL. This indicates that SL is coordinated with the Li+, Na+, K+ by one oxygen atom.The coordination numbers of the Li+ < Na+ < K+ cations increase in the series 4.5 < 5.4 < 5.6 for SL and 0 < 0.1 = 0.1 for the ClO4 -, correspondently.The work was carried out within the framework of the theme of state assignment No. 21111900148-3. Reference Yamaguchi T., Yamada H., Fujiwara T. and Hori K. 2020 Mol. Liq. 312 113288Dokko K., Watanabe D., Ugata Y., Thomas M. L., Tsuzuki S., Shinoda W., Hashimoto K., Ueno K., Umebayashi Y. and Watanabe M. 2018 Phys. Chem. B. 122 47Sheina L.V., Karaseva E.V. and Kolosnitsyn V.S. 2021 J. Phys. Chem. A. 95 5 Figure 1

Rice husk-derived carbon materials for aqueous Zn-ion hybrid supercapacitors

High-performance rice husk-derived carbonaceous electrode materials for aqueous zinc-ion hybrid supercapacitors (ZHSCs) were prepared via a simplistically one-step molten salt carbonization process in molten eutectic Na2CO3-K2CO3 at 750, 850 and 950 °C. ZHSC assembled by Zn foil as an anode and carbon material prepared at 850 °C as a cathode delivers 149.8, 120.1, 108.7, 100.3, 89.3, 80.7 and 69.8F g−1 from 0.2 to 20 A g−1 in 3 mol L−1 Zn(CF3SO3)2 aqueous solution with a rate performance of 47 % capacitance retention. It exhibited energy (power) density with 58.6 Wh kg−1 (167.8 W kg−1) at 0.2 A g−1 and power (energy) density with 10.0 kW kg−1 (9.7 Wh kg−1) at 20 A g−1 as well as excellent cyclic stability with 95.8 % capacitance retention and coulombic efficiency of 99.9 % after 3005 charge-discharge cycles at 2 A g−1. The relationship between structure and electrochemical energy storage performance is also discussed with performance depending on the synergistic effect of porous structure, specific surface area, electrical conductivity and heteroatom doping of rice husk-derived carbon materials.

Modeling of electrical conductivity of graphene-based polymer nanocomposites: calculation from the first principles

The use of nanocomposite materials has led to progress in the creation of new electronic devices (minitransistors, sensors, micro-drives, which are used to build artificial muscles, and supercapacitors. Nanocomposites occupy a special place with magnetosensitive fillers, particularly successfully used in medicine. Nanocomposites are also used for a protective coating. Depending on the operational functions, achieving a specific conductivity value and its change with temperature is necessary for such a coating. In the work, a conductivity model of polymer nanocomposites based on graphene (Gr/PS) was obtained using experimental data. The largest relative deviation between the conductivity surface and experimental data does not exceed 9.5%. The expression was obtained for the graphene concentration 1 &lt; C(Gr) &lt; 30 wt % and the temperature range 20 &lt; T &lt; 100 °C. The dependence of the specific electrical conductivity on the filler concentration and temperature obtained in the work will allow the researchers to select a nanocomposite with the required conductivity and evaluate the temperature effects on it for the conditions to which the material will be exposed.

Sustainable Thermoelectric Materials Predicted by Machine Learning

AbstractUsing datasets from several sources, a list of more than 450 materials is generated and related them with their thermoelectric properties. This is obtained by generating a set of features using only the molecular formula. Subsequently, a machine learning algorithm classifies the materials in specific, binary classes, for example, possessing high or low Seebeck coefficients or electrical conductivity. After adjusting the threshold values and grouping the materials into clusters, the thermoelectric performance of more than 25k materials is predicted. Finally, the results are filtered to obtain only the sustainable materials, that is, neither toxic nor critical, (ideally) inexpensive, and isotropic with regard to their transport properties to simplify the preparation procedure.

Revisiting Michael Bonell's work on humid tropical rainforest catchments: Isotope tracers reveal seasonal shifts in catchment hydrology

It has been almost 50 years since the foundational work at the Babinda catchments in North Queensland kickstarted the field of tropical hydrology globally. To expand upon this work and build a more generalized hydrological understanding of steep rainforest catchments, we studied the seasonal evolution of hydrological response from two catchments with broadly similar characteristics to the Babinda catchments. Both hydrometric and water stable isotope data were collected at relatively high frequencies during one wet season (Thompson Creek) and a 3-year period (Atika Creek). The longer dataset spans a wide range of environmental conditions experienced in the humid tropics, including events that cover the wetting-up transitional period of the wet season and tropical cyclones (TC). Both catchments displayed a fast streamflow response to rainfall with the shallow upper soil profile responding quickly to rainfall at Atika Creek. New findings from this study include the importance of pre-event water (>50% using the two component hydrograph separation technique) for overall event flows, especially when the catchment was wet. Rainfall, surface runoff and groundwater isotope and specific electrical conductivity (SEC) compositions varied between rainfall events with the most complex bivariate mixing plots observed for multi-peak events that occurred at the start of the wet season and after a dry period within the wet season. Two-tracer, 3 component hydrograph separations did not provide satisfactory results in identifying source water contributions to streamflow. These results highlighted the time-variant and non-conservative behaviour of the rainfall, surface runoff and shallow groundwater source waters over the seasonal timescale, with soil water being an important unidentified source contributor. Our findings highlight the need for high frequency multi-source sampling to accurately interpret catchment behaviour and the importance of soil water contributions to streamflow. We propose a framework to describe the seasonal evolution of streamflow response in steep tropical rainforest catchments experiencing seasonal rainfall activity.

Investigation of the Influence of Technological Operating Conditions of Electric Discharge Installations on the Pre-Breakdown Characteristics of an Electric Discharge

This work deals with the influence of the parameters of the working fluid (hydrostatic pressure, temperature, electrical conductivity) and the geometry of the electrode system (the length of the interelectrode gap and the uninsulated part of the anode) on the pre-breakdown characteristics of an electric discharge in a liquid aqueous electrolyte (breakdown voltage and breakdown delay time) and the minimum charging voltage, which provides a stable high-voltage breakdown of the interelectrode gap. Studies have shown that an increase in the hydrostatic pressure leads to an increase in most of the studied characteristics. At the same time, an increase in the specific electrical conductivity and temperature was observed to lead to their decrease. At the same time, it was suggested that the effect of temperature on the pre-breakdown characteristics is associated with a change in the specific electrical conductivity of the working fluid during its heating. The data obtained showed no effect of the length of the interelectrode gap on the breakdown voltage and its breakdown delay time, as well as the minimum charging voltage. The results of the experimental studies made it possible to develop a criterion for determining the charging voltage, which provides a stable high-voltage breakdown of the water interelectrode gap. Its experimental verification has shown that it can be applied to the design of electric discharge equipment and to the choice of technological modes of operation in the specified range of parameters.

Phase relations, structure, properties and DFT study of compounds in the Sc-rich part of the systems Sc-{Mn,Fe,Co,Ni}-Ga

Phase relations, structure, properties and DFT study of compounds in the Sc-rich part of the systems Sc-{Mn,Fe,Co,Ni}-Ga

In situ lysimeter experiment of leaching pollutants from municipal waste with physicochemical status and microbiome condition

• Effluents have a specific electrical conductivity similar to landfill leachates. • The microbiological activity in the tested leachate samples shows seasonality. • Temperatures in summer reduced the ability of the microbiome to oxidize polymers. Lysimeter tests are an ideal supplement to monitoring tests performed in the area of landfills. This article presents an interdisciplinary lysimeter experiment that used hydrogeological, biochemical, and microbiological studies to evaluate the process of leaching pollutants from waste. The obtained results of leachate tests indicate that the EC value was as high as 31 mS/cm which corresponds to poor water quality. Additionally, high concentrations of chlorides (up to 5095 mg/L) and sulphates (up to 10107 mg/L) were observed. The results of microbiological tests confirm the seasonality. The statistically significant (p < 0.05) difference in the number of heterotrophic bacteria was denoted between autumn (1.6·107 CFU cm-3) and winter (1.5·105 CFU cm-3.The analysis of the ability to utilize nitrogen and phosphorus sources showed seasonal differences in the use of substrates containing these biogenic elements. It was observed that nitrogen-containing compounds were most intensively used in winter and the least in spring while phosphorus compounds were the most intensively oxidized in summer. Presented results confirm that lysimeter studies can play a valuable role in the construction of landfills for the best method of waste isolation and limiting the growth of microorganisms.

Comparative Characteristics of Polymethacrylic Acid Hydrogel Sorption Activity in Relation to Lanthanum Ions in Different Intergel Systems

Phenomena of remote interaction in intergel systems polymethacrylic acid hydrogel – poly-4-vinylpyridine hydrogel (hPMAA-hP4VP) and polymethacrylic acid hydrogel – poly-2-methyl-5-vinylpyridine hydrogel (hPMAA-hP2M5VP) have been studied. It was found that there is a decrease of specific electric conductivity, pH and swelling degree of PMAA, P4VP, P2M5VP hydrogels during lanthanum ions sorption by the intergel systems. Significant increase of sorption properties (up to 30 %) in intergel systems comparatively with individual hydrogels of PMAA, P4VP, P2M5VP points to the fact of high ionization during mutual activation of the polymers. Maximum sorption of lanthanum ions occurs at the ratios of 17%hPMAA:83%hP4VP and 50%hPMAA:50%hP2M5VP. Data on obtained IR spectra evidence to the sorption of the rare-earth metal by these intergel systems. The obtained results show a significant importance of possible application of intregel systems based on rare-crosslinked polymer hydrogels of acid and basic nature for creation of new innovative sorption technologies in hydrometallurgy.

Multifunctional non-woven fabrics based on interfused MXene fibers

MXene-based fibers are expected to have the hopeful potential for manufacturing multifunctional fabrics with permeability, lightweight, remarkable electrical conductivity, and outstanding mechanical properties. However, the weak interaction between fibers limits the performance of the fabrics, and researchers are still seeking a suitable solution and easily scalable production methods. Here a green and novel wet-assembly approach is proposed for producing non-woven MXene fiber fabrics (MFFs) constructed by random-oriented and well-connected interfused MXene fibers. The as-prepared fabrics are porous and lightweight while exhibiting high electrical conductivity (708 S cm−1). A maximum specific electrical conductivity is achieved with a relatively low density (0.24 g cm−3), even superior to individual MXene fibers. Moreover, the MFFs exhibit outstanding electromagnetic interference (EMI) shielding effectiveness of 75.0 dB at a thickness of 107 μm, exceptional Joule heating (up to 370 °C at a voltage of 3.5 V), and excellent photothermal conversion abilities, showing their great potential as high-performance and multifunctional fabrics in EMI shielding, wearable intelligent garments, and personal heating applications.

Foamed Carbon-Supported Nickel-Iron Oxides Interspersed with Bamboo-Like Carbon Nanotubes for High-Performance Rechargeable Zinc-Air Batteries.

The development of multi-component bi-functional electrocatalysts is necessary for commercialization of high-performance zinc-air batteries. Herein, foamed carbon-supported nickel-iron oxides interspersed with bamboo-like carbon nanotubes are prepared as bi-functional electrocatalysts for this battery type. During high temperature synthesis, edges of carbon sheets comprising the foamed carbon structure become involuted to form short carbon nanotubes. The composite of carbon nanotubes and network carbon confer high specific surface area and high electrical conductivity on the newly prepared materials. The supported NiFe2 O4 phase improves the oxygen reduction reaction (ORR) activity by fixing more N atoms, and high-valent Ni oxide (Ni2 O3 ) promotes the formation of OO bonds, which is conducive to the oxygen evolution reaction (OER). The optimized material exhibits excellent bi-functional electrocatalytic activity toward both ORR and OER, and its use in the assembled zinc-air battery cell results in a high power density of 150mWcm-2 with long discharge stability.

The pseudocapacitance and sensing materials constructed by Dawson/basket-like phosphomolybdate

Three phosphomolybdate hybrid derivatives, (H2bib)2.5{HP2Mo18O62}·2H2O (1), (H2bib){Sr⊂H4P6Mo18O73}·6H2O (2), (H2bib)3[{Co(H2O)2}{Sr⊂P6Mo16ⅥMo2Ⅴ O73}]·6H2O (3) (bib ​= ​1,4-Bis(imidazolyl)butane) were built by bib inducer via in situ hydrothermal reaction and fully characterized. Compounds 1 and 2 are bib modified Dawson and basket-like hybrids with complex topologies, respectively. In structure of 3, {P6Mo18O73} polyanions arranged in ABAB manner are alternately bridged by {Co(H2O)2} unit to yield an extended wavy chain, which was expanded into supramolecular sheets and infinite 3-D meshwork. The irregularly shaped tunnels are produced in the spatial structure of 3. The electrochemical tests show compound 3 presents enhance specific capacitance (797.8 ​F·g−1at 3 A/g), cycle efficiency (96.5% after the 5000th cycle), electrical conductivity, and catalytic activity than those of compounds 1 and 2 due to its structure advantages. Moreover, 3-GCE exhibits electrochemical responses to AA at potential of 0.3 ​V with the lower detection line of 0.16 ​μM, the wider linear range of 4.00 μM–4.72 ​mM, merit selectivity and reproducibility. The merit capacitive and sensing properties of 3 are attributed to introduction of transition metal Co, which not only provides additional redox active sites, but also bridges the basket clusters to form ordered tunnels that providing the necessary paths for ion or electron transmission.

Novel ZnFe2O4@MnO2@MXene composites with ultrathin thickness and excellent electromagnetic absorption performance

A flower-like ZnFe2O4@MnO2 composite with core-shell structures was prepared by a hydrothermal method. MXene nanosheets were fabricated by etching titanium aluminium carbide (Ti3AlC2) and further ultrasonic exfoliation. A ZnFe2O4@MnO2@MXene composite was synthesized by electrostatic self-assembly with negatively charged MXene nanosheets and positively charged ZnFe2O4@MnO2 composite. MXene nanosheets, having a large specific surface area and high electrical conductivity, can provide more conductive pathways. The incorporation of ZnFe2O4 and MnO2 contributes to enhanced interfacial polarization and impedance matching. The ZnFe2O4@MnO2@MXene composite shows better electromagnetic wave absorption (EMA) performance than ZnFe2O4 and the ZnFe2O4@MnO2 composite. The minimum reflection loss (RLmin) of the ZnFe2O4@MnO2@MXene composite reaches −50.4 dB at a frequency of 15.3 GHz with a thickness of 1.40 mm, while the effective absorption bandwidth (EAB) reaches 4.7 GHz (13.3–18.0 GHz). The EMA mechanism of the composite was revealed. This study can provide a strategy for the structural designation of high-performance EMA materials.

A novel detection strategy for nitrofuran metabolite residues: Dual-mode competitive-type electrochemical immunosensor based on polyethyleneimine reduced graphene oxide/gold nanorods nanocomposite and silica-based multifunctional immunoprobe

Excessive residues of semicarbazide (SEM) can accumulate in animals after the original drug has been abused, posing a risk to human health. Herein, based on multifunctional silica-initiated dual mode signal response, a novel competitive-type immunosensor was constructed for ultrasensitive detection of SEM. As a preliminary signal amplification platform for immunosensors, polyethyleneimine reduced graphene oxide composite gold nanorods (PEI-rGO/AuNRs) modified gold electrodes (AuE) provide a high specific surface area and high electrical conductivity. The thionine-aminated silica nanospheres-AuPt (thi-SiO2@AuPt) were synthesized by a racile coprecipitation method for enzyme immobilization and redox species loading. The multifunctional silica nanosphere conjugated with labeling antibodies (Ab2) was employed as an immunoprobe. The per unit concentration target of SEM can be determined by differential pulse voltammetry (DPV) to detect the thi loaded on the immunoprobe, which can also be determined by square wave voltammetry (SWV) to detect the current generated by the reaction system of H2O2 and hydroquinone (HQ) catalyzed by the immunoprobe with peroxidase. Under optimal conditions, the proposed immunosensor displayed a wide linear range from 1 μg-0.01 ng/mL and low detection limits (S/N = 3) of 0.488 pg/mL and 0.0157 ng/mL, respectively. Ultimately, the developed method exhibits excellent performance in practical applications, providing promising probabilities for SEM detection.