Wave Anodic Stripping Voltammetry Research Articles (Page 1)

The detection and monitoring of mercury ions (Hg2+) in water have become increasingly critical due to their extreme toxicity, bioaccumulation potential, and regulatory significance under international frameworks such as the Minamata Convention. Persistent mercury contamination continues to affect water systems in both developed and developing nations, including India and the United Kingdom. As a step towards detecting mercury (Hg2+) in water samples, we have developed miniaturized point-of–analysis electrochemical sensor based on a new metal-free, thiadiazole (TDA) and triazine (Trz) linked porous organic polymer (TDA-Trz-POP). Unlike conventional sensors that rely on metal-based recognition elements, our heteroatom-rich POP enables highly selective Hg²⁺ capture via synergistic sulphur and nitrogen coordination. The resulting sensors exhibit a lower limit-of-detection (LoD) as 1.5 nM (≈ 0.4 ppb, below the WHO Limit of 6 ppb) and a Linear range of 5–100 nM (1.4 to 27 ppb). The selective and sensitive detection of Hg2+ attributed to the nitrogen- and sulphur-rich surface functionalities of the TDA-Trz-POP-modified electrode, with the underlying binding mechanism is discussed in detail. Using square wave anodic stripping voltammetry (SWASV), we demonstrate real-sample applicability in water, offering a robust, low-cost, and scalable solution for on-site mercury detection in groundwater. The present work is among the first demonstrations of a metal-free porous organic polymer (POP) integrated into SPEs for point-of-analysis mercury sensing with huge potential for public health in developing nations.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-19241-x.

3D-printed extraction chamber and paper-based screen-printed sensors for zinc analysis in soil and Antarctic sediments.

In this study, Bi2O3/CeO2 nanocomposite was synthesized using serine, which played a dual role by promoting uniform particle morphology and aiding combustion during synthesis, resulting in a highly porous nanostructure. The produced nanocomposite was applied as a highly efficient modifier for screen-printed electrode (Bi2O3/CeO2/SPE), facilitating the simultaneous quantification of Pb(II) and Cd(II) using square wave anodic stripping voltammetry (SWASV). Compared to conventional sensors, the proposed electrode exhibited significantly enhanced electrochemical behavior, attributed to the synergistic structural and electrical properties of CeO₂ and Bi₂O₃ as well as an increased surface area. The sensor demonstrated a reliable response and effective peak separation at optimal parameters. The current signals exhibited linearity within the concentration range between 0.5 and 85µg/L for both ions, achieving the limit of detection (LOD) of 0.09µg/L for Pb(II) and 0.14µg/L for Cd(II). The Bi2O3/CeO2/SPE was effectively utilized to detect cadmium and lead ions in water and food samples, demonstrating high recovery values across different spiked samples, and the outcomes closely matched those obtained through standard ICP analysis.

The toxicity of metal ions, such as lead (Pb2+) and cadmium (Cd2+), has been a worldwide issue since the 1970s. For Pb2+ specifically, chronic exposure via drinking water can have lasting health effects. While inductively coupled plasma‐mass spectrometry (ICP‐MS) and atomic absorption spectroscopy (AAS) are the most common instruments used for the detection of Pb2+, electrochemical methods like square wave anodic stripping voltammetry (SWASV) have classically shown promise. However, the determination of metals in a real sample matrix typically requires pretreatment and/or extraction of the analyte from the sample itself. Cloud point extraction (CPE) is a sustainable technique that can be used as a solventless substitute for liquid–liquid or solid‐phase extraction. While typically coupled to AAS detection, the applicability of CPE to electroanalysis is still not well understood, nor fully optimized. In this work, CPE was used to isolate Pb2+ from water samples for analysis by SWASV with a bismuth‐coated glassy carbon (Bi‐GC) electrode. This is the first report coupling CPE to electroanalytical detection of trace metals in the absence of mercury (Hg). In addition, a back extraction (BE) step was incorporated to recover Pb2+ from the surfactant‐rich phase, which resulted in a more sensitive and accurate method. High extraction efficiency was achieved and theoretical limits of detection (LOD) of 2.6, 0.81, and 1.7 μgL−1 were obtained with deposition times (tdep) of 1, 2, and 3 min, respectively. The optimized CPE‐SWASV procedure for Pb2+ was selective; only manganese (Mn2+) was identified as an interferant. Measurements in more complex water samples were also completed. Overall, this innovative CPE‐SWASV approach offers a sensitive, cost‐effective, and sustainable alternative to Hg‐based electrochemical quantification of Pb2+.

Lead (Pb) and cadmium (Cd) ions have serious negative impacts on human health and the ecological environment due to toxicity, persistence and nonbiodegradability. Among various trace Pb and Cd ions detection technologies, electrochemical analysis is considered as one of the most promising methods. The deposition of Bi nanoparticles on delaminated Ti3C2Tx (DL-Ti3C2Tx) develops a sensor with good conductivity and performance. Square wave anodic stripping voltammetry (SWASV) technology was applied to simultaneously deposit Bi on DL-Ti3C2Tx/GCE and achieve the rapid detection of Pb and Cd ions. The Bi nanoparticles effectively improved the sensitivity of Bi/DL-Ti3C2Tx/GCE sensors to detect Pb and Cd ions. The preparation conditions of the Bi/DL-Ti3C2Tx/GCE were optimized, including DL-Ti3C2Tx droplet amount, solution pH, Bi3+ concentration, deposition time and deposition potential, to improve the detection ability. The Bi/DL-Ti3C2Tx/GCE sensor has detection limits of 1.73 and 1.06 μg/L for Pb and Cd ions, respectively (S/N > 3). This electrochemical sensor is easy, sensitive and selective to apply in actual water samples for trace Pb and Cd ions detection.

Development of an electrochemical sensor utilizing MWCNs-poly(2-aminothiophenol) @AgNPs nanocomposite for the simultaneous determination of Pb2+ and Cd2+ in food samples.

A critical review of electrochemical (bio)sensors for liposoluble antioxidants.

Novel gold nanoparticles-Schiff base electrochemical sensor for the determination of lead (II) ions in biological samples.

We combined Au nanoparticles with Copper-1,3,5-benzene dicarboxylate (Cu-BTC) to modify the glassy carbon electrode (GCE) for Sb determination in water by square wave anodic stripping voltammetry (SWASV). Sb(V) is reduced to Sb(III) by potassium iodide (KI) and ascorbic acid (AA), allowing Sb(V) determination by subtracting Sb(III) from total Sb. The sensor's selectivity and stability stem from Sb-Cu2+ interaction, Cu-BTC's 3D structure, electrocatalytic activity and conductivity of gold nanoparticles (AuNPs). The sensitivity and detection limit of Sb(III) were 0.38 μA/μg/L and 0.24 μg/L. The sensitivity and detection limit of Sb(V) were 0.32 μA/μg/L and 0.38 μg/L. The Au/Cu-BTC sensor showed good reproducibility and recoveries in natural waters, showing promise for the practical determination of Sb(III/V) species.

Considering the extremely high toxicity of lead (Pb), early detection of atmospheric Pb levels is paramount for the implementation of preventive measures, to contain sources of emission, to minimize both human and plant exposure and to prevent accumulation in the biosphere. This work demonstrates a wearable "on-plant" sensor for electrochemical Pb detection in atmospheric aerosol samples. The sensor is screen-printed onto a flexible self-adhesive vinyl-based matte substrate which enables its attachment on plant leaves. It features a bismuth/Nafion-coated carbon working electrode transducer covered with a polyvinyl alcohol (PVA) membrane which serves as a passive in-situ gas collection layer and as an electrolyte-containing matrix. The Pb collected at the interface between the sample in the gas phase and the acetate buffer solution (ABS) embedded within the PVA membrane is measured by square wave anodic stripping voltammetry (SWASV). Different steps of the fabrication process were optimized and the detection of on plant leaves was demonstrated. Simulation experiments were conducted with a Pb-containing aerosol sprayed on the leaves to evaluate the effect of various operational parameters such as long-term stability, spraying time, accumulation time, or sensor/leaf bending. The "on-plant" sensor allows remote near real-time monitoring of Pb levels as low as 50μgL-1 in ambient air using a portable miniaturized potentiostat, and can be expanded to other target metals, forming the basis of an early warning system for atmospheric heavy metals exposure.

Methylmercury (CH3Hg+), a lipophilic environmental pollutant, accumulates in fish, shellfish, and other organisms, posing significant risks to human health through the food chain. Developing a convenient and sensitive analytical method for CH3Hg+ detection is crucial for reducing costs and enhancing the efficiency of food safety testing. In this study, we prepared an octyl-modified silica isoporous membrane on the indium tin oxide (ITO) electrode (Octyl-SIM/ITO) via the electrochemical-assisted self-assembly (EASA) method using octyltrimethoxysilane (O-TES) as the functional organosilane. The Octyl-SIM/ITO electrode exhibits vertically-ordered nanochannels and strong hydrophobic affinity, enabling selective penetration and enrichment of weakly polar analytes. Utilizing square wave anodic stripping voltammetry (SWASV), the Octyl-SIM/ITO electrode demonstrates superior electrochemical response signals for CH3Hg+ detection, achieving a detection limit as low as 4 nM. This method allows for accurate and reproducible detection of CH3Hg+ in fish and oyster samples with minimal sample preparation, offering promising potential for portable in situ detection.

Excessive levels of heavy metal pollutants in the environment pose significant threats to human health and ecosystem stability. Consequently, the accurate and rapid detection of heavy metal ions is critically important. A AgNPs@CeO2/Nafion composite was prepared by dispersing nano-ceria (CeO2) in a Nafion solution and incorporating silver nanoparticles (AgNPs). The morphology, microstructure, and electrochemical properties of the modified electrode materials were systematically characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and cyclic voltammetry (CV). By leveraging the oxygen vacancies and high electron transfer efficiency of CeO2, the strong adsorption capacity of Nafion, and the superior conductivity of AgNPs, an AgNPs@CeO2/Nafion/GCE electrochemical sensor was developed. Under optimized conditions, trace Pb2+ in water was detected using square wave anodic stripping voltammetry (SWASV). The sensor demonstrated a linear response for Pb2+ within the concentration range of 1-100 μg·L-1, with a detection limit of 0.17 μg·L-1 (S/N = 3). When applied to real water samples, the method achieved recovery rates between 93.7% and 110.3%, validating its reliability and practical applicability.

Heavy metals such as cadmium, lead, arsenic, mercury, and chromium are harmful to human health, even in a trace amount. Despite existing guidelines and regulations for handling these toxic substances, mortality cases among wild animals due to heavy metal poisoning continue to occur. To effectively investigate the sources of heavy metal contaminants in the environment, it is essential to establish real-time monitoring systems across affected areas. This paper presents the design and development of a potentiostat device (HMstat) with the capability to perform a square wave anodic stripping voltammetry (SWASV). The HMstat was realized using a two-board type potentiostat design, incorporating through-hole technology for the analog component and the myRIO platform for the digital component. Performance evaluations indicated that the HMstat is capable of performing the SWASV method. The results demonstrated that the HMstat achieved an accuracy of 99.014%, remained within the tolerance range of components used and surpassed the existing solution.

The rapid increase in waste production, driven by the Industrial Revolution, has led to significant environmental challenges, particularly the contamination of soil and water from landfill leachate. This study aims to evaluate the removal of heavy metals (zinc, cadmium, and lead) from landfill leachate through chemical precipitation using the analytical technique of square wave voltammetry by anodic re-dissolution. The study involved sequential stages, starting with adjustments to the electroanalytical method and calibration curve development, followed by precipitation assays with a synthetic metal solution to optimize variables for heavy metal removal. Precipitation experiments were conducted using zinc, cadmium, and lead ions with calcium hydroxide and sodium carbonate, and voltammetric analyses were performed using square wave anodic stripping voltammetry to assess metal concentrations. The study examined the electrochemical behavior of Bi³? using square wave voltammetry, revealing linear relationships between peak current and frequency, indicating reversibility in the reaction. Optimization of parameters such as frequency, step, and pulse amplitude improved the precision and selectivity of the analysis. Bi³? concentration was optimized for maximum electroanalytical response, with a concentration of 1.25 mg L?¹ selected. Deposition time was also optimized, with 300 seconds providing the best results. Metal removal efficiency using precipitating agents (Ca(OH)? and Na?CO?) was analyzed, showing higher efficiency for lead and cadmium with Ca(OH)?. The study highlights the significance of pH and agent concentration in the removal process. This study evaluated the removal of heavy metals (zinc, cadmium, and lead) from landfill leachate using chemical precipitation with calcium hydroxide and sodium carbonate. The process achieved high removal rates, particularly for lead (97.97%). Square wave voltammetry was successfully developed for precise quantification, with statistical validation confirming its reliability for this application.

Abstract Electrolytic manganese is essential for the metallurgical industry; therefore, electrolytics baths for its production have become excellent alternative, making their analytical control a priority. In this research, a carbon paste electrode (CPE) modified with bismuth powder (CPE-Bi) was developed for the first time for Mn2+ determination by square wave anodic stripping voltametric (SWASV), allowing the Mn quantification in samples from an electrolytic bath, facilitating its monitoring. A univariate method was used to optimize the CPE-Bi composition, pH, and the electrodeposition parameters, maximizing the analytical signal in Mn2+ determination through the anodic peak current (Iap). The parameters related to the square wave anodic stripping voltammetry (SWASV) were optimized by Box Behnken experimental design. The proposed methodology was successfully applied to determine Mn2+ in electrolytic bath samples, achieving recovery percentages of 96.29% ± 9.25%, suggesting it is suitable for Mn monitoring. The limit of detection of 6.5x10-6 M, sensitivity of 7.5726 μA μM-1 in a lineal range of 2.17x10-5 M to 1x10-4 M with precision of 3.27%, highlight the method’s great sensitivity, precision, and accuracy, attributed to the properties provided by bismuth powder and the electrochemical technique used, making it an excellent alternative for the Mn2+ analysis in the mining industry.

This study explores the development of an advanced electrochemical sensor designed for the simultaneous detection of Cd2+, Pb2+, Cu2+, and Hg2+ ions. The sensor utilizes sol-gel-synthesized bismuth vanadate (BiVO4) nanospheres, which are integrated onto a glassy carbon electrode (GCE), and employs square wave anodic stripping voltammetry (SWASV) for electrochemical determination of heavy metal ions. The as-prepared sensor demonstrated exceptional analytical performance and offered a wide linear detection range from 0 μM to 110 μM, along with low detection limits of 2.75 μM for Cd2+, 2.32 μM for Pb2+, 2.72 μM for Cu2+, and 1.20 μM for Hg2+ ions. These characteristics made the sensor highly suitable for precise monitoring of heavy metal contamination in both environmental and industrial samples. Beyond their sensing capabilities, the BiVO4 nanospheres also exhibited significant antimicrobial activity against bacterial strains such as E. coli and S. aureus, as well as fungal strains like C. albicans and C. parapsilosis. This antimicrobial effect was attributed to the enhanced surface reactivity and the generation of reactive oxygen species (ROS), which disrupt microbial cellular functions. This dual-functional approach highlighted the substantial progress in both electrochemical sensing and antimicrobial applications. This research presents a strong platform for tackling urgent challenges in environmental monitoring and microbial control.

This study explores the potential of using magnetic biochar derived from sesame seed cake (PMBS) and enhanced with polyaniline (PANI) for the removal of heavy metals from aqueous solutions. The synthesized PMBS was comprehensively characterized and evaluated as an effective adsorbent for Hg2+ and Cu2+ removal. This study assessed various physicochemical properties, including surface morphology, porosity, specific surface area, chemical composition, valence states, and magnetic characteristics, of the composite to determine its efficacy in heavy metal removal from wastewater. The adsorption performance of the magnetic biochar was significantly enhanced via PANI doping. Furthermore, the easy magnetic recovery of PMBS from aqueous solutions after adsorption was successfully demonstrated using an external magnetic field. The adsorption kinetics of heavy metal ions on PMBS followed a pseudo-second-order model, while Langmuir isotherm analysis confirmed monolayer adsorption behavior. The maximum adsorption capacities for Hg2+ and Cu2+ were determined to be 141.89 and 124.78 mg g−1, respectively. The electrochemical measurements of square wave anodic stripping voltammetry (SWASV) were employed to determine residual metal ion concentrations after adsorption. Calibration curves were constructed by varying the concentration of each ion, both individually (with the other held constant) and simultaneously (with both ions present in the same solution), to evaluate the electrode's performance in mixed-ion systems. The PANI-modified PMBS biochar demonstrates significant potential for wastewater treatment and is suitable for a broader range of separation applications.

A new electrochemical sensor devoted to Hg(II) trace determination was developed by tailoring a hybrid organic/inorganic interface using diazonium salts and gold nanoparticles (AuNPs). The AuNPs were electrodeposited for the very first time onto glassy carbon (GC) electrodes functionalized by thick (ca. 4 nm) diazonium films. The thickness of the organic films was obtained using atomic force microscopy (AFM) in scratching mode, while the AuNPs were characterized by field emission gun scanning electron microscopy (FEG‐SEM). Each step of the functionalization process was studied by cyclic voltammetry using ferricyanide and ruthenium hexaammine as the redox probes. The as‐prepared electrode was used for Hg(II) trace detection through square wave anodic stripping voltammetry (SWASV). A linear response was observed in the 1.0–9.9 nmol·L−1 range using a preconcentration time of 300 s, yielding a normalized sensitivity of 0.03 μA·L·nmol−1·min−1. The limit of detection (LOD) was determined to be as low as 300 pmol·L−1. The effect of major interfering metal cations on the sensor’s response was also investigated. In addition, the hybrid organic/inorganic interface strongly enhanced the lifetime of the sensor, this latter being extended up to 4 weeks.

Assessing heavy metal ion (HMI) contamination to sustain drinking water hygiene is a challenge. Conventional approaches are appealing for the detection of HMIs but electrochemical approaches can resolve the limitations of these approaches, such as tedious sample preparation, high cost, time consuming and the need for trained professionals. Here, an electrochemical approach is developed using a nano-sphered polypyrrole (PPy) functionalized with MoS2 (PPy/MoS2) by square wave anodic stripping voltammetry for the detection of HMIs. The developed sensor can detect Pb2+ with a limit of detection of 0.03 nM and a sensitivity of 36.42 μA nM-1. Additionally, the PPy/MoS2 sensor was employed for the simultaneous detection of HMIs of Cd2+, Pb2+, Cu2+ and Hg2+. The reproducibility, stability and anti-interference studies confirm that the sensor can be used to monitor HMI contamination of water.

The detection of lead ions (Pb2+) in water is of critical importance due to the harmful effects of lead on human health and the environment. Traditional detection methods often require high user expertise, expensive equipment, and complex analytical procedures. Electrochemical sensors have emerged as effective alternatives due to their portability and affordability. In this study, a novel electrochemical sensor was developed for the sensitive and selective detection of Pb2+ based on glassy carbon electrodes (GCE) modified with bimetallic metal-organic frameworks (MOFs) and reduced graphene oxide (rGO). The bimetallic MOFs were successfully synthesized via a hydrothermal method, combining two metal centers Fe and Mg linked to a 1,4-benzene dicarboxylate ligand (FeMg-BDC). The synthesized FeMg-BDC has higher conductivity and surface area than monometallic Fe-BDC or Mg-BDC MOFs. Thanks to the synergistic effects between FeMg-BDC and rGO, the rGO/FeMg-BDC electrode has a larger electrochemically active surface area and faster electron transfer rate than the bare GCE. This enhancement facilitated the accumulation of lead onto the electrode surface, thereby improving the sensitivity of Pb2+ ion detection. Using the square wave anodic stripping voltammetry method, the sensor based on rGO/FeMg-BDC electrode exhibited two linear ranges: 0.01 to 0.5 μg L-1 and 0.5 to 50.0 μg L-1, with a low limit of detection (LOD) of 9 ng L-1. Furthermore, the external rGO thin film protects the FeMg-BDC material on the electrode surface, ensuring high durability and repeatability of the sensor. The developed sensor was successfully applied to accurately determine lead ion concentrations in various real water samples.