Determination of Pesticides in Water Using Carbon Voltammetric Sensors
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-07-15 |
| Journal | Chemické listy |
| Authors | Zuzana KramplovĂĄ, Jana BlaĆĄkoviÄovĂĄ, Andrea PurdeĆĄovĂĄ |
| Institutions | University Library in Bratislava, University of Ss. Cyril and Methodius in Trnava |
| Analysis | Full AI Review Included |
Executive Summary
Section titled âExecutive SummaryâThis review analyzes the use of carbon-based voltammetric sensors as a high-performance, cost-effective alternative to conventional chromatographic techniques (LC-MS/GC-MS) for detecting electroactive pesticide residues in water.
- Core Value Proposition: Voltammetry (specifically DPV and SWV) offers high sensitivity, speed, and simplicity, enabling potential online or field-deployable monitoring of environmental contaminants.
- Key Materials: The sensing platforms are based on carbon electrodes, primarily Boron-Doped Diamond (BDDE), Glassy Carbon (GCE), and Carbon Paste (CPE).
- Performance Enhancement: Ultra-low Limits of Detection (LODs) are achieved through extensive surface modification using:
- Carbon Nanomaterials (rGO, CNTs).
- Metal Nanoparticles (AuNPs, CuNPs, PdNPs).
- Biological Elements (Enzymes like Acetylcholinesterase, AChE).
- Sensitivity Achieved: LODs frequently reach the pico- to femtomolar range (e.g., 1.4·10-15 M for Methyl-parathion), surpassing the requirements for trace analysis.
- BDDE Advantages: BDDE is highlighted for its wide potential window (up to 3 V) and resistance to fouling, making it ideal for analyzing complex environmental matrices.
- Operational Efficiency: The methods often require minimal sample pre-treatment (e.g., simple filtration), significantly reducing analysis time and operational complexity compared to conventional lab techniques.
Technical Specifications
Section titled âTechnical Specificationsâ| Parameter | Value | Unit | Context |
|---|---|---|---|
| Best LOD (Methyl-parathion) | 1.4·10-15 | M | Achieved using AChE/N-MAL-CD/SPE sensor (CV) |
| Best LOD (Malathion) | 3.27·10-15 | M | Achieved using AChE/Ag@Ti3C2Tx/GCE sensor (DPV) |
| BDDE Potential Window | Up to 3 | V | Range available for analysis, dependent on electrolyte |
| European MRL (Total Pesticides) | 0.5 | ”g l-1 | Maximum Residue Limit for human consumption water |
| European MRL (Single Pesticide) | 0.1 | ”g l-1 | Maximum Residue Limit for human consumption water |
| Glyphosate LOD (DPV) | 1.1·10-9 | M | CuAl-LDH/GrNC sensor |
| Lindan LOD (SWV) | 32.0 | nM | GCE/Nylon 6,6/MWCNT/Fe3O4 sensor |
| GCE Carbon Hybridization | sp2 | N/A | Non-organized graphitic layers, providing good conductivity |
| GCE Modification Material Example | GdNbO4 Nanoparticles | N/A | Used to enhance detection of Aclonifen (LOD: 1.15 nM) |
Key Methodologies
Section titled âKey MethodologiesâThe high performance of these sensors relies on specific material selection and the application of sensitive pulse techniques:
-
Electrode Platform Selection:
- BDDE: Chosen for its stability, low background current, and ability to operate across a wide potential range (up to 3 V), facilitating the oxidation of many pesticides.
- GCE: Selected for its chemical inertness, good electrical conductivity, and ease of surface modification via chemical or electrochemical deposition.
- CPE: Utilized for its simplicity of preparation and cost-effectiveness, often modified with binders and carbon nanomaterials.
-
Surface Modification Strategies:
- Nanomaterial Integration: Incorporation of materials like reduced Graphene Oxide (rGO), Carbon Nanotubes (CNTs), and Metal-Organic Frameworks (MOFs) to maximize active surface area and enhance electron transfer kinetics.
- Electrocatalysis: Use of metal nanoparticles (e.g., Au, Ag, Cu) or metal oxides (e.g., TiO2, Fe3O4) to specifically catalyze the redox reaction of the target pesticide.
- Biomolecule Immobilization: Enzymes (e.g., AChE) are immobilized, often within polymer matrices (e.g., Nafion), to create highly selective biosensors, typically targeting organophosphate pesticides via inhibition mechanisms.
- Molecular Imprinting Polymers (MIPs): Used to create artificial recognition sites on the electrode surface, offering high selectivity and stability compared to biological receptors.
-
Voltammetric Detection Techniques:
- Cyclic Voltammetry (CV): Primarily used for fundamental electrochemical characterization, determining redox potentials and reaction reversibility.
- Differential Pulse Voltammetry (DPV) & Square-Wave Voltammetry (SWV): The preferred techniques for quantitative analysis due to their superior sensitivity (lower LODs) compared to CV and LSV. SWV is generally faster.
- Adsorptive Stripping Voltammetry (SWAdSV): Employs a pre-concentration step where the analyte is adsorbed onto the electrode surface, followed by a stripping scan (SWV), dramatically improving sensitivity for trace analysis.
Commercial Applications
Section titled âCommercial ApplicationsâThe development of highly sensitive, robust carbon voltammetric sensors directly supports several critical engineering and environmental sectors:
| Industry/Sector | Application/Product Focus | Technical Requirement Met |
|---|---|---|
| Water Quality Management | Real-time, continuous monitoring systems for pesticide residues in municipal drinking water sources and reservoirs. | High sensitivity (nM to pM range) required to meet strict MRLs (0.1 ”g l-1). |
| Agricultural Technology | Development of portable, field-deployable sensors for rapid testing of irrigation water and agricultural runoff. | Fast response time and minimal sample preparation (often just filtration) for on-site analysis. |
| Environmental Remediation | Monitoring the efficiency of pesticide degradation processes in contaminated soil and water treatment systems. | Stability and corrosion resistance (e.g., BDDE) for use in potentially harsh chemical environments. |
| Food and Beverage Testing | Rapid screening tools for raw materials and final products to ensure compliance with global food safety standards. | High selectivity achieved through modified electrodes (MIPs, enzyme biosensors) to avoid matrix interference. |
| Analytical Instrumentation | Integration of modified carbon electrodes into compact, low-power, handheld analytical devices. | Simplicity of operation and low cost compared to benchtop LC-MS/GC-MS systems. |
View Original Abstract
Electrochemical methods, especially voltammetry, offer a promising alternative to conventional chromatographic techniques for the determination of electroactive pesticides in water samples. This review article summarizes current knowledge on voltammetric detection techniques (cyclic voltammetry (CV), linear-sweep voltammetry (LSV), differential pulse voltammetry (DPV), square-wave voltammetry (SWV)) and carbon-based electrode materials (e.g., boron-doped diamond electrode (BDDE), glassy carbon electrode (GCE), carbon paste electrode (CPE)). Special attention is given to the advantages of each technique, electrode surface modifications, and achieved analytical parameters. Due to their high sensitivity, ease of use, and potential for online monitoring, carbon-based electrochemical sensors can serve as an efficient tool for environmental analysis of pesticide residues.