Electrochemical Monitoring Research Articles

Experimental Investigation of Chloride Ion Monitoring in Concrete Considering the Coupling Effect of Temperature and Humidity

Ag/AgCl electrodes have acquired significant research attention due to their crucial role in the electrochemical monitoring of chloride ion concentration. However, the electrode potential is susceptible to changes in temperature and humidity, and comprehensive investigations regarding the influence of moisture are lacking. Existing studies on Ag/AgCl electrodes have been qualitative, primarily focusing on analyzing the trend of electrode potential to detect variations in Cl- concentration. This study proposes an experimental method that enables precise control of temperature and humidity within concrete. The effects of temperature and humidity coupling on Ag/AgCl electrode potential in a concrete environment and a fundamental model were established correlating Ag/AgCl electrode potential with temperature, humidity, and chloride ion concentration, thereby enhancing the sensing accuracy. The developed model corrected errors from temperature and humidity coupling effects on the Ag/AgCl electrode potential. A quantitative investigation on using Ag/AgCl electrodes for monitoring Cl- concentration was conducted, facilitating their application in engineering and the development of non-destructive monitoring systems for chloride ions in concrete structures.

Real-time electrochemical monitoring sensor for pollutant degradation through galvanic cell system

Real-time electrochemical monitoring sensor for pollutant degradation through galvanic cell system

Efficient biosorption of Zn(II), Cd(II), and Pb(II) by Aspergillus brasiliensis in industrial wastewater coupled with electrochemical monitoring via sensor enhanced with modified silver nanoparticles.

This work investigates the use of Aspergillus brasiliensis, this particular species of Aspergillus, as a biosorbent for the first time. It is employed to biosorption Zn(II), Cd(II), and Pb(II) and combines the biosorption experiments with electrochemical measurements for in situ analysis. For the experiments, a batch system was employed with the dead biomass. In order to determine the biosorption capacity, the impact of several operational parameters was examined, including pH, temperature, agitation speed, contact time, and initial metal concentration, and the optimum values were 5, 30°C, 150rpm, 2h, and 150ppm, respectively. Using 0.2g biomass in 100mL solution, the maximal uptake of Zn(II), Cd(II), and Pb(II) at ideal conditions was determined to be 33.67, 24.51, and 36.76, respectively. The Langmuir and Freundlich isotherm model was studied for the biosorption process. An electrochemical sensor using nanomaterials is designed and constructed to monitor the concentration of these metals. The silver nanoparticles functionalized with thiosemicarbazide and 6-mercaptohexanoic acid (mercaptohexanoylhydrazinecarbothioamide-coated silver nanoparticles, MHHC-AgNPs) linked to the carboxylated multi-walled carbon nanotubes (MWCNTs) were utilized for glassy carbon electrode modification (MHHC-AgNPs/MWCNTs/GCE). The concentration range of Zn(II) is 0.7-173µg/L, Cd(II) is 1.18-293µg/L, and Pb(II) is 2.17-540µg/L. The detection limits for Zn(II), Cd(II), and Pb(II) are 0.036µg/L, 0.15µg/L, and 0.16µg/L, respectively. Under optimized conditions, these results were obtained using the differential pulse anodic stripping voltammetry method (DPASV). The successful detection of Zn(II), Cd(II), and Pb(II) was achieved by effectively preventing interference from other common ions. It was effectively employed for measuring ions in industrial wastewater, and the results obtained aligned with those acquired from an atomic absorption spectrometer (AAS). Thus, Aspergillus brasiliensis species, along with this electrochemical sensor, can be used to remediate and monitor environmental pollution, Zn(II), Cd(II), and Pb(II), successfully.

Surface modification of Au nanoparticles with porous carbon microsheets/Bi2S3 for enhanced electrochemical monitoring of hazardous sulfamethoxazole

Surface modification of Au nanoparticles with porous carbon microsheets/Bi2S3 for enhanced electrochemical monitoring of hazardous sulfamethoxazole

Durability and mechanical properties of concretes with limestone filler with particle packing

This study aims to present alternatives to reduce the demand of cement in concrete production based on particle packing concepts. Physical and mechanical characteristics of concretes, as well as the resistance to chlorides action were analyzed. The tests conducted in this study included compressive strength, chloride migration, capillary absorption tests and wetting and drying cycles in 1M sodium chloride solution. Mixtures containing limestone filler presented satisfactory results compared to the reference mixture with particle packing. Excellent results were obtained for concrete with cement consumption of 253.34 kg.m-3 in terms of compressive strength, binder index, capillary absorption and depassivation time of rebars, thus reinforcing the concept that partial cement replacement by limestone filler yields positive results in these properties. Worse results were obtained for concrete with a cement consumption of 161.86 kg.m-3, because it had a higher proportion of filler than cement. The electrochemical monitoring of the steel bars also shows that the packing of the aggregates was essential to delay the initiation of corrosion.

Demyelination detection in CSF based on electrochemical monitoring of myelin basic protein in comparison between Apta vs. Immuno sensing strategies

Multiple sclerosis (MS) is a recurrent inflammatory, demyelinating disease of the white matter in central nervous system (CNS). The number of MS patients is increasing, but the diagnostic process is still quite difficult, costly and requires combination of several methods. Myelin basic protein (MBP) makes up to 30 % of the myelin in CNS. It is known that MBP is released into the cerebrospinal fluid (CSF) as MS bioindicator. Herein, myelin specific DNA aptamer earlier developed for possible therapeutic purposes and anti-MBP antibody were applied as bioreceptors for MBP recognition on the same nanomodified sensor surfaces and their performances were compared. Biosensors were developed by using graphene oxide (GO) nanoparticles integrated onto pencil graphite electrodes (PGE) and bioreceptor molecules immobilized to create a bioactive layer for MBP binding. The measurements were run with electrochemical impedance spectroscopy (EIS). Selectivity of the biosensors was evaluated using human serum albumin (HSA). After optimization of binding parameters, biosensors were validated in artificial CSF. It was shown that LJM-5708 based aptasensor had LOD 0.65 ng/mL that was comparable to immunosensor LOD (0.36 ng/mL) in artificial CSF and showed its applicability in the clinical concentration range between 1 and 128 ng/mL.

Carbon-based Nanocomposite Materials for Electrochemical Monitoring of Cadmium Ions

In the present era of science and technology, cadmium poisoning in humans is reported from several parts of the world and now it is a global health problem. Accumulation of cadmium in human organs and tissues, such as the liver, kidney, etc., leads to carcinogenic effects and toxicity to the organ system. Therefore, several efforts are being made to develop a monitoring system for cadmium metal ions in the environment. This review aimed to summarise the different carbon-composite materials-based electrochemical sensors reported to date for cadmium ions detection. The first section of this review provides a brief discussion on the source and harmful effects of cadmium ions, and the rest part includes different carbon (graphite, graphene, graphene oxide, carbon nanotubes, etc.)-based composite nanomaterials reported to date for the electrochemical detection of cadmium ions in different analytes. Carbon-based nanocomposite materials have been found to be very suitable for the detection of Cd(II) ions due to their boosted electron transportation and high surface, leading towards high sensitivity and high selectivity.

Advanced Electrochemical Monitoring of Carbendazim Fungicide in Foods Using Interfacial Superassembly of NRPC/NiMn Frameworks.

A simple, sensitive and reliable sensing system based on nitrogen-rich porous carbon (NRPC) and transition metals, NRPC/Ni, NRPC/Mn and NRPC/NiMn was developed and successfully applied as electrode materials for the quantitative determination of carbendazim (CBZ). The synergistic effect of NRPC and bimetals with acceptable pore structure together with flower-like morphology resulted in producing a highly conductive and interconnected network in NRPC/NiMn@GCE, which significantly enhanced the detection performance of CBZ. The electrochemical behavior investigated by cyclic voltammetry (CV) showed improved CBZ detection for NRPC/NiMn, due to the controlled adsorption/diffusion process of CBZ by the NRPC/NiMn@GCE electrode. The influences of various factors such as pH, NRPC/NiMn concentration, CBZ concentration and scan rate were studied. Under optimal conditions, 0.1 M phosphate-buffered saline (PBS) with a pH of 7.0 containing 30 µg/mL NRPC/NiMn, a favourable linear range detection of CBZ from 5 to 50 µM was obtained. Moreover, a chronoamperometric analysis showed excellent repeatability, reproducibility and anti-interfering ability of the fabricated NRPC/NiMn@GCE sensor. Furthermore, the sensor showed satisfactory results for CBZ detection in real samples with acceptable recoveries of 96.40-104.98% and low RSD values of 0.25-3.45%.

Sonochemically Synthesised Nano‐Stone Structured Vanadium Tungstate for Electrochemical Monitoring of Antibiotic Drug Nitrofurantoin in Real Samples

AbstractThe development of simple, accurate, responsive, and selective antimicrobial drug analysis platforms is extremely important for biomedical research. Developing a novel electrode material that possesses low detection limit, high sensitivity, and stability continues to be a difficult undertaking. Here, vanadium tungstate nanostones (VWNs) were synthesized by utilizing facile sonochemical method with the aid of urea and ethylene glycol for application in electrochemical sensing of antibiotic drug nitrofurantoin (NFT). Using a distinct analytical methods, the structural and morphological characteristics of the as‐prepared transducer material were described. Further, electrochemical behaviour of modified electrode were analysed using cyclic voltammetry and liner sweep voltammetry. Under the optimal conditions VWNs/GCE electrode exhibited superior electrocatalytic activity towards NFT with linear range (20–160 μM), limit of detection (0.019 μM) with better sensitivity (0.69 μM−1 cm−2). The modified electrode demonstrated remarkable repeatability, reproducibility, and excellent stability, indicating its potential as an electrocatalyst. Ultimately, the suggested electrode was used to measure FLT in real samples like tap water and NFT capsule.

Surface-engineered vertically-aligned ZnO nanorod for sensitive non-enzymatic electrochemical monitoring of cholesterol

Developing highly sensitive and selective non-enzymatic electrochemical biosensors for disease biomarker detection has become challenging in healthcare applications. However, advances in material science are opening new avenues for creating more dependable biosensing technologies. In this context, the present work introduces a novel approach by engineering a hybrid structure of zinc oxide nanorod (ZnO NR) modified with iron oxide nanoparticle (Fe2O3 NP) on an FTO electrode. This Fe2O3 NP-ZnO NR hybrid material functions as a nanozyme, facilitating the catalysis of cholesterol and enabling the direct transfer of electrons to the fluorine-doped tin oxide (FTO) electrode, limiting the need for costly and traditional enzymes in the detection process. This innovative non-enzymatic cholesterol biosensor showcases remarkable sensitivity, registering at 642.8 μA/mMcm2 within a linear response range of up to 9.0 mM. It also exhibits a low detection limit (LOD) of ∼12.4 μM, ensuring its capability to detect minimal concentrations of cholesterol accurately. Moreover, the developed biosensor displays exceptional selectivity by effectively distinguishing cholesterol molecules from other interfering biological species, while exhibiting outstanding stability and reproducibility. Our findings indicate that the Fe2O3 NP-ZnO NR hybrid nanostructure on the FTO electrode holds promise for enhancing biosensor stability. Furthermore, the present device fabrication platform offers versatility, as it can be adapted with various enzymes or modified with different metal oxides, potentially broadening its applicability in a wide range of biomarkers detection.

Electrochemical Monitoring for Molten Salt Pyroprocessing of Spent Nuclear Fuel: A Review

Electrochemical Monitoring for Molten Salt Pyroprocessing of Spent Nuclear Fuel: A Review

Gold nanoparticle decorated bismuth vanadate casting on screen-printed electrode for chlortetracycline detection

Chlortetracycline is one of the tetracyclines with broad-spectrum antibacterial activity (CTC). Humans rarely use CTC, but farm animals consume vast quantities of it, which causes the growth of antibiotic-resistant bacteria and environmental contamination. There is no report on the AuNPs and BiVO4 nanocomposite being dropped cast on SPCE for electrochemical monitoring of the CTC, and the most expensive, time-consuming, and expensively equipped method is conventional chromatography. Here, we report a simple method for preparing gold nanoparticle decorated bismuth vanadate (AuNPs@BiVO4), which was dropped cast on a screen-printed carbon electrode (SPCE). The AuNPs@BiVO4 and AuNPs@BiVO4/SPCE materials were characterized using TEM, SEM-EDX, XPS, DLS, ELS, EIS, and CV, showing a consistent nanocomposite and its electrode. The as-prepared AuNPs@BiVO4/SPCE was used to detect and determine chlortetracycline (CTC) by different pulse potentials in phosphate buffer pH 7.0. The electrode possessed a wide linear range of 0.99–19.06 µM, with obtained LOD = 0.15 µM, LOQ = 0.49 µM, and sensitivity = 0.059 μA μM−1 cm−2. It also exhibited good selectivity, stability, and repeatability, recovering 87.14 %–100 % for detecting CTC in Mili Q and tap water. The findings show that the straightforward approach for making AuNPs@BiVO4 nanocomposite and an AuNPs@BiVO4/SPCE electrode is consistent with electrochemical CTC monitoring. Thus, the proposed electrode could be applied for the detection and determination of CTC in water sources and has the potential to be used for real sample analysis.

Electrochemical performance monitoring and degradation modeling method for organic coating systems: Integrating three-phase Wiener process and kinetic models

The deterioration of organic anticorrosive coating systems not only diminishes the lifetime of underlying metals but also incurs substantial economic losses and the risk of unforeseen catastrophes. Thus, rigorously monitoring and accurately predicting the lifetime of organic anticorrosive coatings are crucial. In this paper, we introduce a new approach for monitoring the electrochemical performance and predicting the durability of organic coatings. Initially, we propose a model grounded in degradation mechanisms that merges an aging kinetic model of the coating with the three-phase Wiener process, accurately representing the degradation trajectory and its inherent uncertainties. We then apply change point detection techniques, utilizing the t distribution test and the Schwarz Information Criterion, to delineate the three distinct phases of coating degradation. By defining new failure criteria based on degradation thresholds and stages, we develop a reliability model for coating systems and apply the Fiducial Inference-Monte Carlo method for numerical solutions and interval estimations. To corroborate the efficacy of our methodology, we designed electrochemical sensors for coatings and executed accelerated degradation experiments in the laboratory. The model parameters derived from the initial three sets of test data successfully predict the behavior of the fourth data set, verifying the effectiveness of the proposed method.

Long-lasting copper carbon nanotubes for non-enzymatic electrochemical sensing of glyphosate

Accurate electrochemical detection of glyphosate (GLY) presents significant challenges due to its non-electroactive nature on conventional electrode materials. To address this challenge, copper-modified electrodes have been developed to form a complex with GLY, enhancing detection capabilities. In this study, we propose an innovative material: copper-modified carbon nanotubes on a glassy carbon electrode (Cu/CNT/GCE). The detection mechanism of GLY using Cu/CNT/GCE involves the formation of a copper-GLY complex, which inhibits the electrochemical response of copper, proportionally to the GLY concentration. This effect is enhanced by the synergistic interaction between copper and carbon nanotubes, increasing the electrochemical stability and detection capacity of the system. To evaluate the electrochemical performance of Cu/CNT/GCE, cyclic voltammetry was performed at different electrolyte concentrations and pH levels. Square wave voltammetry was employed for the electrochemical quantification of GLY, showing a linear correlation between GLY concentration and the inhibition of the copper response. The proposed sensor exhibited a low limit of detection (0.098 ppm) and a limit of quantification (0.326 ppm). Furthermore, the electrode demonstrated long-term stability, retaining 95 % of its signal after one year of storage. This stability is attributed to the carbon nanotube support, which prevents corrosion of copper particles. Recovery values ranged from 94 to 106 % for Citromax™ and Orium™ glyphosate with precision. The method showed excellent selectivity for GLY detection, even in the presence of other herbicides such as diuron and oryzalin. These properties suggest that Cu/CNT/GCE presents promising features for the electrochemical monitoring of GLY in diverse environmental samples.

Electrochemical Monitoring of Respiratory Infectious Disease on Nanostructured Surface Functionalized with Biosynthetic Multimer Aptamers

Multivalent aptamers have gained substantial interest owing to their enhanced affinity towards target analytes compared to their monomeric counterparts due to their capability to bind simultaneously to diverse regions of a target molecule, fostering more robust and enduring interactions. This study focuses on engineering the surface-based production and modification of multivalent aptamers through room temperature rolling circle amplification technique and chemically modified primers. This process starts with immobilizing modified primers onto an electrode to generate and arrange biosynthesised multivalent aptamers. These bio-engineered multivalent aptamers are utilized as bio-receptors for capturing a specific target (in this case, the SARS-CoV-2 spike protein). The entire surface amplification procedure is extensively characterized using electrochemical, microscopy, and spectroscopy methods, determining the optimal amplification duration for biosensing applications. Impressively, multivalent aptasensors shows substantially increased response signals and affinity compared to monomeric aptasensors. Moreover, the influence of surface structures on response signals is explored by employing both flat screen-printed gold electrodes and nano-/microisland (NMI) electrodes. NMIs-based multimeric aptasensors demonstrate notably heightened sensitivity in detecting SARS-CoV-2 spike protein within the range of 10 to 106 fg/mL in saliva and buffer media. Finally, the signal of the proposed aptasensor has been successfully assessed using several patient samples.

Monitoring the Corrosion Resistance of Cold-Spray Coatings with Membrane-Based Sensors

Ensuring the management of gas transportation infrastructure requires the monitoring of internal corrosion within pipelines. The utilization of membrane-based electrochemical sensors is a promising advancement in corrosion risk monitoring. These sensors demonstrate an ability to operate within humidified gas environments, previously inaccessible to conventional electrochemical monitoring methods. Simultaneously, ongoing research is delving into novel sacrificial coatings and application methods to prolong the lifespan of existing pipeline structures and minimize associated repair costs. In this context, we broaden the application of membrane-based electrochemical sensors to investigate the response of electrodes equipped with cold-spray coatings. This examination encompasses a range of fluids exhibiting varying levels of corrosivity pertinent to natural gas pipelines. Multiple sensors with 316 stainless steel working electrodes were coated with cold spray sacrificial coating then exposed to humidified gases with differing relative humidities (RH) (5 %, 50 %, and 95 %) and condensed phases with differing salt content (deionized water and 0.1 mol kg-1 NaCl solution). Three electrochemical techniques (potentiometry, impedance spectroscopy and potentiodynamic scans) were used to monitor the corrosive environment and probe the extent of coating coverage. For the conditions studied, impedance values were extremely sensitive to changes in water content through changes in the membrane resistance (from ~1 kΩ in deionized water to ~5 MΩ with 5 % RH). Polarization resistances (Rp) consistently decreased with increasing corrosivity (~3 kΩ in deionized water to 15 GΩ with 5 % RH). Scanning electron microscopy and energy dispersive X-ray spectroscopy were used to identify the extent to which corrosion products permeated the membrane after major corrosion events.

Back Cover: Electrochemical Monitoring of Real‐Time Vesicle Dynamics Induced by Tau in a Confined Nanopipette

Back Cover: Electrochemical Monitoring of Real‐Time Vesicle Dynamics Induced by Tau in a Confined Nanopipette

Back Cover: Electrochemical Monitoring of Real‐Time Vesicle Dynamics Induced by Tau in a Confined Nanopipette

Back Cover: Electrochemical Monitoring of Real‐Time Vesicle Dynamics Induced by Tau in a Confined Nanopipette

Electrochemical Monitoring of Real‐Time Vesicle Dynamics Induced by Tau in a Confined Nanopipette

AbstractThe microtubule‐associated protein tau participates in neurotransmission regulation via its interaction with synaptic vesicles (SVs). The precise nature and mechanics of tau‘s engagement with SVs, especially regarding alterations in vesicle dynamics, remain a matter of discussion. We report an electrochemical method using a synapse‐mimicking nanopipette to monitor vesicle dynamics induced by tau. A model vesicle of ~30 nm is confined within a lipid‐modified nanopipette orifice with a comparable diameter to mimic the synaptic lipid environment. Both tau and phosphorylated tau (p‐tau) present two‐state dynamic behavior in this biomimetic system, showing typical ionic current oscillation, induced by lipid‐tau interaction. The results indicate that p‐tau has a stronger affinity to the lipid vesicles in the confined environment, blocking the vesicle movement to a higher degree. Taken together, this method bridges a gap for sensing synaptic vesicle dynamics in a confined lipid environment, mimicking vesicle movement near the synaptic membrane. These findings contribute to understanding how different types of tau protein regulate synaptic vesicle motility and to underlying its functional and pathological behaviours in disease.

Electrochemical Monitoring of Real-Time Vesicle Dynamics Induced by Tau in a Confined Nanopipette.

The microtubule-associated protein tau participates in neurotransmission regulation via its interaction with synaptic vesicles (SVs). The precise nature and mechanics of tau's engagement with SVs, especially regarding alterations in vesicle dynamics, remain a matter of discussion. We report an electrochemical method using a synapse-mimicking nanopipette to monitor vesicle dynamics induced by tau. A model vesicle of ~30 nm is confined within a lipid-modified nanopipette orifice with a comparable diameter to mimic the synaptic lipid environment. Both tau and phosphorylated tau (p-tau) present two-state dynamic behavior in this biomimetic system, showing typical ionic current oscillation, induced by lipid-tau interaction. The results indicate that p-tau has a stronger affinity to the lipid vesicles in the confined environment, blocking the vesicle movement to a higher degree. Taken together, this method bridges a gap for sensing synaptic vesicle dynamics in a confined lipid environment, mimicking vesicle movement near the synaptic membrane. These findings contribute to understanding how different types of tau protein regulate synaptic vesicle motility and to underlying its functional and pathological behaviours in disease.