Wave Voltammetry Research Articles

Investigation of the electrochemical behaviour of praseodymium ions in a LiF-PrF3-Pr6O11 molten salt system

Understanding the electrochemical of paseodymium ions in molten salt is essential to improve electrolytic efficiency. To elucidate the electroreduction mechanism of praseodymium ions and overcome the limitations associated with regulating the yield of praseodymium metal in the industrial praseodymium electrolysis process, the electrochemical behaviour of praseodymium on the W working electrode surface in the LiF-PrF3-Pr6O11 molten salt system was determined by square–wave voltammetry, chronoamperometry, cyclic voltammetry and potentiometry analyses. The results indicated that the reduction of Pr3+ on the W cathode is a one-step quasireversible Pr3+/Pr reduction process controlled by diffusion of the LiF-PrF3 and (LiF-PrF3)eut-Pr6O11 electrolytes at 1223 K Pr3+ in the LiF-PrF3-Pr6O11 molten salt has a diffusion coefficient of DPr3+/Pr = 0.20 × 10−8–4.11 × 10−8 cm2·s−1. The incorporation of Pr6O11 increased the electrochemical activity of Pr3+ in the LiF-PrF3 system. Pr crystallization on the W electrode was achieved by three-dimensional progressive nucleation.

Field-deployable pencil lead-based electrochemical cell for the determination of the emerging contaminant and antidepressant drug venlafaxine in wastewater

Screening and quantification of emerging contaminants in water is of enormous relevance due to its scarcity and harmful effects on aquatic life and human health. We present a simple and cost-effective electrochemical cell for determination of the antidepressant venlafaxine, an emerging contaminant included in the EU Watch list 2022. The cell consists of pencil leads used as electrodes and a microcentrifuge tube. Modification of the working electrode with carbon nanomaterials improved the signal. Cell-related (e.g., type of pencil leads or electroactive area) as well as experimental (e.g., pH, accumulation potential and time, and scan rate) parameters were thoroughly optimized. The adsorptive nature of venlafaxine process allowed the use of an adsorptive stripping square wave voltammetry methodology to increase the sensitivity. Under optimized variables, a linear range from 0.8 to 10 μmol L−1 with a correlation coefficient of 0.996, a sensitivity of 1.48 μmol L−1, a LOD of 0.4 μmol L−1 and a RSD of 2.4 % were achieved. Selectivity was also studied, especially with respect to the main metabolite, o-desmethylvenlafaxine. The methodology distinguishes its signal from that of the main compound, allowing its determination. A similar linear range was obtained for the metabolite, with a LOD of 0.6 μmol L−1. The platform developed was applied for venlafaxine quantification in spiked wastewaters from the Febros plant in Portugal, obtaining satisfactory recoveries. Furthermore, the versatility of pencil leads made it possible to combine them with modified paper for sampling and buffering in order to decentralize the determination, showing promising results.

Electrochemical behavior of tantalum ions in molten salt electrolysis for nano-powder preparation

This research focused on analyzing the electrochemical properties of tantalum ions in NaCl-KCl molten salt during the extraction of tantalum and the synthesis of tantalum nano-powder. Tantalum ions were dissolved from the anode. Linear sweep voltammetry, cyclic voltammetry, square wave voltammetry, and chronoamperometry were employed to delve into the reduction and diffusion processes of tantalum ions. The study determined the diffusion coefficient, the nucleation process, and the deposition potential for tantalum ions. The findings revealed that the electrode reduction process of tantalum ions involved a three-step reaction: Ta5+→Ta3+→Ta+→Ta. This reaction was shown to be reversible and diffusion-controlled. The nucleation mode of tantalum ions was identified as instantaneous nucleation followed by progressive nucleation as the potential increased by chronoamperometry analysis. The cathodic deposition product was characterized using XRD, SEM, EDS, and TEM techniques, confirming the nanoscale granular nature and microstructure of the deposition products.

Pyridine functionalized nickel(II) N–heterocyclic carbene complexes as highly sensitive molecular sensors for the electrochemical sensing of date rape drugs

Molecular electrocatalysts featuring a nickel atom within a tailored N–heterocyclic carbene ligand environment are valuable for various electrocatalytic applications. This study presents the synthesis and characterisation of nickel organometallic electrocatalysts based on 1,2,4–triazol–5–ylidene with different steric profiles for the sensitive detection of date rape drugs (DRDs). Bis– N–heterocyclic carbene coordinated nickel(II) complexes were compared, and square wave voltammetry (SWV) showed that these catalysts detected xylazine in the concentration range of 1–100 µM with a limit of detection (LOD) of 0.621 nM. The developed electrocatalyst was also utilized for detecting scopolamine over a concentration range of 1–150 µM, with a LOD of 1.40 nM, as well as γ–butyrolactone in the range of 1–100 µM, with a LOD of 0.638 nM. The selectivity for these DRDs was analysed in the presence of other blood and urine components. The electrodes remained stable over 30 days with minimal performance variation, demonstrating the potential of these electrocatalysts for developing reliable on–site molecular sensors for DRD detection.

Anode process on gold in KF–AlF<sub>3</sub>–Al<sub>2</sub>O<sub>3</sub> melt

In the conditions of resource saving and carbon footprint reduction, the development of oxygen–releasing anodes for technologies of production of important metals and alloys by electrolysis of molten salts seems to be an urgent task. To determine the degree of “inertness” of a particular anode material, data on the kinetics and mechanism of the anode process on a material not subject to oxidation are required. In this connection, the anodic process on gold in the KF–AlF3–Al2O3 melt for electrolytic aluminum production was investigated by cyclic and square–wave voltammetry methods. The influence of temperature (715 and 775 оC) of the melt, the content of Al2O3 in it (from 0.1 to saturation), as well as the polarization rate (0.05–1 V/s) on the kinetics and some features of the mechanism of the investigated process was determined. An assumption is made that oxygen release on gold without dissolution of the substrate takes place in the region of overvoltages from 0 to 0.8 V. It is shown that the process includes the stages of electrochemical adsorption and desorption of the intermediate product, the first of which is limited by the diffusion of electroactive anions to the anode.

Enzymeless Gabapentin Sensor Based on Prussian Blue-modified Indium Tin Oxide Electrodes for Sensing Gabapentin in Capsules

Background: In this study, we reported on developing a susceptible, accurate, simple, and economical electrochemical sensor for gabapentin determination in capsules. Methods: The ITO electrode was modified with a layer of Prussian blue nanoparticles and then used as the working electrode. Gabapentin was extracted from commercial capsules, and a series of concentrations of gabapentin were prepared for studying the efficacy of the proposed sensor. The electrochemical measurements were performed using cyclic voltammetry and square wave voltammetry techniques. Results: The sensitivity and selectivity of the developed electrode toward gabapentin in different interferences, including citric acid, glucose, and urea, were investigated. The modified electrode showed detection and quantification limits of 31.58 and 94.74 nM, respectively, over a dynamic range of concentrations from 100 nM to 3 μM. Conclusion: The proposed sensor displayed a high sensitivity and selectivity for monitoring gabapentin in pharmaceutical drugs without a noticeable interference. Hence, the modified electrodes are great candidates for gabapentin routine analysis.

TiO2 aerogel − A sensing electrode matrix for the sensitive detection of diclofenac sodium

This study developed a new composite matrix containing TiO2 aerogel having mesoporous structure (TiO2AG), bioengineered flagellin (bioF) and chitosan (Ch) deposited on a glassy carbon electrode (GCE), for the detection of diclofenac sodium (DS) in aqueous solutions. It is worth mentioning that TiO2AG mesoporous material was used for the first time as a sensitive matrix for DS detection. The morpho-structural properties of the new electrode materials were assessed by X-ray diffraction (XRD), N2 adsorption–desorption measurements, and scanning electron microscopy (SEM) in conjunction with energy-dispersive X-ray spectroscopy. The electrochemical properties of the new bioF + TiO2AG + Ch/GCE modified electrode were determined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV) techniques. The developed modified electrode exhibits a significant electrocatalytic activity for DS electrooxidation process reflected in the acquired performances (detection limit of 17 nM, sensitivity of 0.41 A/M, linear range from 0.15 to 2.5 µM), and presents excellent reproducibility, repeatability, and stability. The practical use of the new developed electrode was estimated by quantifying DS in pharmaceutical formulations (recovery mean of 100.66 % for DS, with a relative standard deviation of 0.39 %) and wastewater samples (relative error of 3.15 % and a relative standard deviation of 0.393 when compared to the LC-MS standard technique).

10-[(4-Cyanobenzylidene)]-Anthracen-9(10H)-One: syntheses, characterization and application in UV light detection

In this work, the compound 10-[(4-cyanobenzylidene)]-anthracen-9(10H)-one (1) has been synthesized from the corresponding anthrone and 4-cyanobenzaldehyde. It has been characterized by nuclear magnetic resonance (NMR), infrared spectroscopy (IR), high-resolution mass spectroscopy (HRMS) and single-crystal X-ray diffraction (XRD) analysis. Moreover, square wave voltammetry (SWV) was performed to determine the HOMO and LUMO potential levels of the anthrone derivative 1, which indicates that sensitization of TiO2-based electrodes is thermodynamically feasible. Therefore, this characteristic of compound 1 allowed its incorporation in a Grätzel-type solar cell. Photocurrent density measurements under UV irradiation are proportional to the light source intensity, and the operational parameters of the photoelectrochemical cell are relatively stable over time. In fact, the sensitivity of the generated photocurrent normalized by the supplied irradiance for TiO2-1 (7.73 µA/mW) as a photoanode is higher than that of TiO2 alone (5.14 µA/mW), indicating the improvement that 1 provides to TiO2 with respect to UV light detection. The higher photocurrent and the improved stability due to the implementation of 1 are very promising for possible applications as a sensitizer for UV light intensity sensors in dye-sensitized solar cells (DSSC).

Development of a 1D-WO3 and CuO nanocomposite modified electrode for enhanced detection of 2,4-dichlorophenol

A common chlorinated phenol known as 2,4-dichlorophenol (2,4-DCP) was investigated electrochemically using cyclic voltammetry (CV) and square wave voltammetry (SWV). The electrochemical investigation was carried out at 1D nanostructured tungsten dioxide (WO3) and copper (II) oxide (CuO) nanocomposite-modified carbon paste electrode (CPE). The electrode's sensitivity was improved by the WO3/CuO nanocomposite, enabling investigators to more precisely measure the 2,4-DCP's electrochemical characteristics. The hydrothermal method was utilized to synthesize the WO3 NPs. The XRD, AFM, SEM, and EDS techniques were used to characterize the nanocomposite and WO3 NPs. Numerous parameters have been studied, including pH, concentration variation, scan rate variation, and accumulation time. Samples of soil, fruits, and vegetables were examined using the fabricated WO3/CuO/CPE. In the concentration range of 7.0 × 10−8 M to 2.6 × 10−7 M, a linear relationship was established along with the lower limit of detection of 0.17 × 10−8 M and the limit of quantification of 0.57 × 10−7 M. The 0.2 M phosphate buffer (PB) of pH 10.4 increased the peak current, which contributed to the WO3/CuO/CPE sensor's sensing performance and was highly sensitive with respect to 2,4-DCP detection. Anodic peak current was observed for the WO3/CuO/CPE is at -7.45 µA whereas for unmodified CPE is at -1.31 µA. According to the findings, the nanostructured WO3 and CuO nanocomposite showed exceptional sensitivity in identifying the electrochemical characteristics and reactions of 2,4-DCP.

Monomeric and Dimeric Boron (III) Subphthalocyanines Functionalized with 4-Hydroxy-Benzoic Acid as Potential Photosensitizers and Photocatalysts in Sulfoxidation.

Axial modification of boron (III) subphthalocyanine bromides with 4-hydroxy-benzoic acid successfully led to the formation of the macrocycles with anchored 4-carboxyphenoxy group [RsPcPHBA] (R=tBu, H) in the axial position and to a new dimer [sPcPHBAsPc] as minor product. Tri-tert-butyl and unsubstituted subphthalocyanines bearing benzoate ([tBusPcBA], [sPcBA]), phenoxy-group ([tBusPcOPh], [sPcOPh])) in the axial position, have been also investigated as well as control sPcs. All compounds were characterized by NMR, IR, UV-Vis and mass spectrometry. The electrochemical properties were studied using cyclic voltammetry (CV) and square wave voltammetry (SWV). Singlet oxygen generation was systematically measured for all synthesized [RsPcX] by kinetic method of chemical trap decomposition (DPBF) and by determination of phosphorescence of singlet oxygen (at 1270 nm). Axially modified subphthalocyanines exhibit high quantum yields of singlet oxygen (1O2) generation (0.47-0.62). The observed exceptional photostability in oxygen-saturated ethanol or toluene solutions and high 1O2 quantum yields allows to use [tBusPcPHBA] as photocatalysts of selective oxidative transformations of organic sulfides to sulfoxides. Loading the catalyst to 9.7 ⋅ 10-2 mol % made it possible to achieve complete conversion of the substrate (TON up to 1700).

Voltametric detection of methylene blue dye in water at green and chemically synthesized Ag/MWCNT modified electrode

Abstract A well-known textile dye, methylene blue (MB) was electrochemically detected by using glassy carbon electrode (GCE), modified with green and chemically synthesized silver nanoparticles (AgNPs) decorating the surface of functionalized multiwalled carbon nanotubes (fMWCNT). The green and chemical methods were used to synthesize AgNPs, which decorated MWCNT forming MWCNT/Agchm and MWCNT/Aggrn nanocomposite. Comprehensive characterization of the nanomaterials was carried out using energy-dispersive x-ray spectroscopy (EDX) detector-equipped scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV), and x-ray diffraction (XRD). Using XRD, particle sizes were found to be 26.81, 10.05, 5.36, 19.26, and 17.48 nm for Agchm, Aggrn, MWCNT, Agchm/MWCNT, and Aggrn/MWCNT, respectively. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and square wave voltammetry (SWV) were employed for the investigation of the electrochemical properties and behaviour of MWCNT, Agchm, Aggrn, Agchm/MWCNT, and Aggrn/MWCNT electrodes, and higher electron transport capabilities and improved electrochemical activity towards MB on Agchm/MWCNT electrode were demonstrated by the results. Electroanalysis of methylene blue at the modified electrodes with square wave technique SWV was successful. At Agchm/MWCNT modified electrode, a low limit of detection (LOD) of 4.684 and limit of quantification (LOQ) of 14.194 pM, for MB, while at Aggrn/MWCNT modified electrode , an LOD and LOQ of 2.935 and 8.895 pM, were recorded respectively. In real sample analysis, the recovery percentage for Agchm/MWCNT ranged from 90 to 98% (n =3), and Aggrn/MWCNT showed a recovery percentage ranging from 97 to 103% (n = 3). Both electrodes’ remarkable recovery rate attest to their dependability and sensitivity in MB detection.

Molten‐Salt‐Assisted Synthesis of Carbon‐Doped BN Nanosheets for the Sensitive Detection of Paracetamol

AbstractHigh‐performance sensors are in constant demand for health care and environmental protection. In this study, a sensitive paracetamol (PCM) sensor was designed by modifying glassy carbon electrode (GCE) with carbon‐doped boron nitride (BCN/GCE) nanosheets. The BCN nanosheets were synthesized using a molten‐salt method, which ensured the uniformity of size distribution. X‐ray diffraction and transmission electron microscopy results suggested that the carbon‐doping hardly changed the crystal structure and morphology of hexagonal boron nitride (HBN). However, the carbon‐doping can reduce the bandgap, increase the specific surface area and improve the electrical conductivity, which is attributed to the formation of abundant point defects in the BN crystal. These point defects modulate electronic structure and surface activity, and further improve the electrocatalytic properties of BN. The BCN nanosheets exhibited outstanding electrocatalytic activity in the oxidation of paracetamol (PCM). With the help of square wave voltammetry (SWV) method, the BCN/GCE demonstrated linear current response towards PCM covering the concentrations of 0.05–70 μM and 70–200 μM with a detection limit (LOD) of 0.0086 μM. The developed method also showed excellent selectivity and high stability. In addition, the BCN/GCE sensor worked well when it was applied to quantify PCM in actual samples.

Proton conductive 2D MXene-derived potassium titanate nanoribbons fabricated electrochemical platform for trace detection of enrofloxacin

In recent years, due to exceptional properties like broad interlayered spacing and low working potential, MXene-derived titanate nanoribbons have been established as promising electrode materials. Herein, the electrocatalytic activity of MXene-derived potassium titanate nanoribbon was employed to develop a voltammetric sensor for the detection of enrofloxacin. The sensor's significance is to provide a sustainable solution to quantify the presence of enrofloxacin regarding food safety and environmental monitoring. Moreover, to achieve the United Nations' Sustainable Development Goals by preventing antimicrobial resistance to accomplish the One Health approach. Potassium titanate nanoribbons were synthesized using 2D Ti3C2 MXene as an active precursor material, while X-ray diffraction spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, selected area electron diffraction pattern, elemental mapping, and energy-dispersive X-ray spectroscopy were used to characterize the crystallinity, surface and layered morphology of synthesized nanoribbons. The Brunauer-Emmett-Teller (BET) technique was applied to calculate the specific surface area of the synthesized materials. The materials underwent electrochemical characterization using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Later on, the nanoribbons were fabricated on the surface of a glassy carbon electrode, and the electro-oxidative behaviour of enrofloxacin was studied by CV, DPV, square wave voltammetry (SWV) in 0.1 M phosphate buffer (optimized pH 8). The developed sensor depicts a significantly lower limit of quantification of 0.007 μM (≈2.5 μg/L), and an upper limit of quantification of 18 μM (≈6.5 mg/L) along with a limit of detection (LOD) of 0.00279, 0.00803, 0.00881 μM obtained from CV, DPV, and SWV respectively. Furthermore, the developed electrodes show a reliable selectivity to be examined in real complex matrices, i.e. marine water, river water, agricultural soil, organic fertilizer, milk, honey, and poultry egg.

Synthesis of Thioglycolic Acid-Modified Molybdenum Disulfide Nanosheets for Electrochemical Sensing and Its Application in Molnupiravir Detection

In the modern world, population growth, industrialization, and lifestyle changes have led to a rise in existing and new diseases, increasing global drug consumption. Proper pharmaceutical dosage is vital since drugs are only effective within specific concentration ranges. Therefore, developing reliable analytical methods for drug analysis in pharmaceuticals and biological samples is essential. Electroanalytical methods are particularly advantageous due to their low cost, ease of use, and rapid response. This study introduces a highly sensitive electrochemical sensor based on thioglycolic acid (TA)-decorated metallic phase molybdenum disulfide (MP-MoS2) nanosheets for the selective detection of molnupiravir (MOL), an antiviral drug used in Covid-19 treatment. The TA@MP-MoS2 nanomaterial was characterized using FTIR, TEM, and EIS. Screen-printed carbon electrodes (SPCE) were modified with TA@MP-MoS2 nanosheets to evaluate their electro-chemical and catalytic behaviours towards MOL by cyclic voltammetry (CV) and square wave voltammetry (SWV). The sensor displayed a well-defined electro-oxidation signal for MOL at 0.534 V, with the linear responses in two concentration ranges: 0.50–3.40 μM and 3.40–9.55 μM, and a low detection limit of 22.6 nM. The proposed design that has promising results could be an alternative strategy to fabricate the sensitive sensor for the detection of antiviral agents in real samples.

First Voltammetric Determination of Karbutylate via Pencil Graphite, Glassy Carbon, and Boron-Doped Diamond Electrodes in Soil Sample

We investigated the electrochemical behavior of carbamate pesticide-type karbutylate (KB) with boron-doped diamond (BDD), glassy carbon (GC), and pencil graphite (PG) electrode, and analytical determination in real samples. Similar to organophosphate insecticides, carbamate pesticides are produced from carbamic acid and are extensively utilized in agriculture, gardens, and residences. Therefore, a rapid and simple detection of KB in real samples is important. Carbon-based electrodes are widely used in electroanalytical chemistry due to their rich surface chemistry, chemical inertness, broad potential window, low background current, and congruency for various demanding applications. Three different carbon-based electrodes were used. The effect of buffer solutions, scan rate, square wave (SWV), and differential pulse voltammetry parameters on the voltammetric response of KB was tested. The optimum working media for all three electrodes was determined as pH 2.00 phosphate buffer solution and voltammetric measurements were carried out in this media. Under optimum experimental conditions, linear calibration dependences for KB were obtained as 6.00 × 10−7–8.00 × 10−5 M, 4.00 × 10−7–8.00 × 10−5 M, and 8.00 × 10−8–8.00 × 10−5 M with a limit of detection of 2.18 × 10−7, 3.71 × 10−8 M, and 2.66 × 10−8 M by the BDD, GC, and PG electrodes, respectively, using SWV. As a result, sensitive determination of KB has been successfully performed using different carbon-based electrodes in real soil samples.

Composite Material from Waste ABS 3D Filaments and Graphite: A Cost‐Effective and Sustainable Alternative for Electrochemical Sensor Manufacturing and Voltammetric Analysis of Acebutolol

AbstractAdditive manufacturing technology is renowned for its ability to produce components on demand. Presently, the development of sustainable materials has been promoted by Green Chemistry, leading to an increase in the recycling of polymers and other materials for use in 3D printing. In this work, we proposed the construction of a 3D printed electrochemical device using a conductive paste made from 3D printing residues of acrylonitrile butadiene styrene (ABS) filaments and graphite to develop a sustainable sensor for acebutolol detection using square wave voltammetry method. The electrode was characterized using imaging and electrochemical techniques, demonstrating superior electrochemical performance compared to a commercial device. The method exhibited excellent analytical performance with a linear working range from 0.98 to 51.8 μmol L−1 and good detectability (detection limit) of 0.28 μmol L−1. Furthermore, the recycled sensor demonstrated good precision with a relative standard deviation of less than 8.4 % and good accuracy with recovery percentages ranging from 93 to 107 % for monitoring acebutolol in urine and tap water samples. Additionally, the device was free from interference from the matrix and other commonly used drugs, making it suitable for electroanalytical applications and extremely promising.

Electrochemical aptasensor for sensitive detection of staphylococcal enterotoxin type A in milk and fruit juice.

Anaptamer-based electrochemical sensor for the sensitive detection of staphylococcal enterotoxin type A(SEA) is presented. The truncated aptamer AptSEA1.4 used in this work was screened using computational techniques, which reduced the cost of the SELEX screening process. The aptamer-SEA interactions were confirmed by employing circular dichroism (CD) and fluorescence spectroscopy. Afterwards, for developing an electrochemical aptasensor, a fabricated GNR/FTO aptasensor was prepared and characterized using scanning electron microscopy-energy-dispersive X-ray analysis (SEM-EDX), atomic force microscopy (AFM), cyclic voltammetry (CV), and square wave voltammetry (SWV). A detailed investigation of aptamer and SEA interaction in the presence of various experimental conditions was also conducted through SWV and electrochemical impedance spectroscopy (EIS). The aptamer exhibits a strong affinity for SEA, with a dissociation constant (Kd) of 19.93nM. The aptasensor is sensitive, with a lower limit of detection of 12.44pgmL-1. It has good stability, repeatability, and specificity and has displayed highly specific and sensitive detection SEA in spiked packaged mixed fruit juice and milk, with a recovery of 95-110%. The aptasensor has highpromise for detecting SEA in other food items.

Aptamer-Mediated Electrochemical Detection of SARS-CoV-2 Nucleocapsid Protein in Saliva.

Gold standard detection of SARS-CoV-2 by reverse transcription quantitative PCR (RT-qPCR) can achieve ultrasensitive viral detection down to a few RNA copies per sample. Yet, the lengthy detection and labor-intensive protocol limit its effectiveness in community screening. In view of this, a structural switching electrochemical aptamer-based biosensor (E-AB) targeting the SARS-CoV-2 nucleocapsid (N) protein was developed. Four N protein-targeting aptamers were characterized on an electrochemical cell configuration using square wave voltammetry (SWV). The sensor was investigated in an artificial saliva matrix optimizing the aptamer anchoring orientation, SWV interrogation frequency, and target incubation time. Rapid detection of the N protein was achieved within 5 min at a low nanomolar limit of detection (LOD) with high specificity. Specific N protein detection was also achieved in simulated positive saliva samples, demonstrating its feasibility for saliva-based rapid diagnosis. Further research will incorporate novel signal amplification strategies to improve sensitivity for early diagnosis.

The rapid detection of pesticide residues in fruits and vegetables using electrochemical methods

To meet global demand, pesticides play a very important role in the control of pests that damage agricultural products. However, overuse of pesticides threatens ecosystems and human health. In recent years, gas chromatography, liquid chromatography, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, capillary chromatography and capillary electrophoresis have been used in the determination of pesticides. Although these methods are highly specific, highly selective and sensitive, the high value of sophisticated laboratory equipment and tools is a complex and time-consuming process. Because of this, electrochemical sensors and biosensor platforms have become good analytical methods for detecting pesticides due to a number of advantages, including ease of detection of system manufacturing processes, high sensitivity and selectivity. This article describes the methods of manufacturing portable electrochemical sensors for detecting pesticide residues in fruits and vegetables on site, that is, the achievements in recent years in the field of cyclic voltammetry, square wave voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. In addition, detailed information is provided on the basic mechanism and electrochemical sensitivity of these methods. The development of electrochemical methods and real-time monitoring of smartphone technologies, as well as their integration with detection platforms, are discussed. For readers with a scientific and technological focus, this article will provide additional valuable information for understanding the creation of portable electrochemical devices, rapid detection of pesticides, the role of electrochemical sensitive methods and contributing to their further development.

Green Voltammetric Detection of Ophthalmic Drug Nepafenac Using Pencil Graphite Electrode as a Responsive Disposable Electrochemical Sensor

AbstractIn this study, the electrochemical properties of nepafenac, used after eye surgery operations, were investigated on a disposable pencil graphite electrode. Cyclic and square wave voltammetry techniques were used to investigate the electrochemical properties of nepafenac. Two peaks at potentials of approximately +0.33 V and +1.03 V in the anodic direction and two peaks at potentials of approximately +0.29 V and +0.08 V in the cathodic direction were observed on the surface of the disposable pencil electrode in acetate (pH 4.8) medium with the cyclic voltammetry technique. The analytical performance of the developed voltammetric technique had good linearity in the concentration range of 0.30 µM to 3.5 µM at pH 4.8. The LOD value of this voltammetric method in acetate (pH 4.8) medium was calculated as 0.035 µM (8.90 ng mL−1). For reproducibility, the relative standard deviation (RSD) values for Ia and IIa anodic peak current/potential were found to be 1.45%/0.43% and 1.28%/0.25%, respectively. The voltammetric method was successfully applied to urine and pharmaceutical preparations and the results were compared with the spectrophotometric method.