Behavior of the guanosine monophosphate modified boron-doped diamond electrode in the presence of the pesticide alachlor
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2015-10-01 |
| Journal | Acta Chimica Slovaca |
| Authors | Jana SvĂtkovĂĄ, ÄčubomĂĆÌ Ć vorc, JĂĄn Labuda |
| Institutions | Czech Academy of Sciences, Institute of Analytical Chemistry, Slovak University of Technology in Bratislava |
| Citations | 4 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Boron-Doped Diamond for Environmental Biosensing
Section titled âTechnical Documentation & Analysis: Boron-Doped Diamond for Environmental BiosensingâThis document analyzes the requirements and findings of the research paper, âBehavior of the guanosine monophosphate modified boron-doped diamond electrode in the presence of the pesticide alachlor,â and aligns them with the advanced MPCVD diamond capabilities offered by 6CCVD.
Executive Summary
Section titled âExecutive SummaryâThis research validates the use of Boron-Doped Diamond Electrodes (BDDE) as a highly stable and sensitive platform for DNA-based biosensors, specifically targeting environmental contaminants.
- Core Application: Development of electrochemical biosensors for the detection and monitoring of the pesticide Alachlor (ALA) in environmental analytical chemistry.
- Material Focus: Utilized high-quality, low-resistivity Boron-Doped Diamond (BDD) with a specified doping level of 1000 ppm and 0.075 Ω·cm resistivity.
- Modification Strategy: BDDE surfaces were chemically modified by immobilizing Guanosine Monophosphate (GMP) and double-stranded DNA (dsDNA).
- Key Finding: The immobilized GMP/DNA layers exhibited concentration-dependent degradation (distortion) when exposed to ALA, monitored via Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS).
- Performance Metric: The charge transfer resistance (Rct) decreased significantly after ALA exposure, confirming the distortion of the biorecognition layer.
- Methodological Strength: The BDD substrate demonstrated superior stability compared to conventional carbonaceous electrodes, making it ideal for long-term biosensor development.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental section, detailing the material requirements and operational parameters.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Diamond Material Type | Boron-Doped Diamond (BDD) | N/A | Used as the working electrode (BDDE). |
| Boron Doping Level | 1000 | ppm | Specified doping concentration for the BDDE. |
| Electrical Resistivity | 0.075 | Ω·cm | Low resistivity required for optimal electrochemical performance. |
| Working Electrode Diameter | 3 | mm | Inner diameter of the BDDE housed in the PEEK body. |
| Ambient Temperature | 25 | °C | Temperature maintained during electrochemical measurements. |
| Supporting Electrolyte | 0.1 | mol/L | Phosphate Buffer Solution (PBS), maintained at pH 6.9. |
| Redox Indicator Concentration | 1 x 10-3 | mol/L | Concentration of the [Fe(CN)6]3-/4- system. |
| Alachlor (ALA) Concentration Range | 4.5 x 10-6 to 4.5 x 10-4 | mol/L | Range used to test layer degradation sensitivity. |
| Initial GMP/BDDE Charge Transfer Resistance (Rct) | 39.7 | kΩ | Measured before incubation in ALA solution. |
| Final GMP/BDDE Charge Transfer Resistance (Rct) | 35.9 | kΩ | Measured after 17 min incubation in ALA solution. |
| Bare BDDE Charge Transfer Resistance (Rct) | 9.5 | kΩ | Baseline resistance of the unmodified electrode. |
Key Methodologies
Section titled âKey MethodologiesâThe BDDE preparation and electrochemical testing followed a precise, multi-step protocol focused on surface modification and stability assessment.
- Surface Preparation: The BDDE was mechanically polished using damp silk cloth until a mirror-like appearance was achieved, minimizing mechanical surface damage.
- Biorecognition Element Immobilization: 8 ”L of Guanosine Monophosphate (GMP) or double-stranded DNA (dsDNA) stock solution was dropped onto the BDDE surface and allowed to evaporate to dryness (12 hours).
- Equilibration: Modified electrodes were immersed in 0.1 mol/L PBS (pH 6.9) for 2 minutes under stirring to achieve equilibrium conditions.
- Stability Testing (PBS): The stability of the modification was confirmed by incubating the electrode in PBS for periods up to 17 minutes, followed by Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) measurements.
- Pesticide Interaction Study: Modified electrodes were incubated in the Alachlor (ALA) solution (4.5 x 10-5 mol/L) for specific time intervals (2, 7, 12, 17 minutes).
- Electrochemical Analysis: CV and EIS were performed using the [Fe(CN)6]3-/4- redox indicator system. Differential Pulse Voltammetry (DPV) was used to monitor the anodic oxidation of the nucleotide base.
- Data Normalization: Results were expressed as normalized current values (ÎIrel) to account for minor variations in electrode reproducibility (RSD < 10%).
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the high-specification diamond materials required to replicate, scale, and advance this research into commercial biosensor applications.
Applicable Materials
Section titled âApplicable MaterialsâThe success of this research hinges on precise control over boron doping and surface quality. 6CCVD offers materials optimized for high-performance electrochemistry:
- Heavy Boron-Doped PCD (BDD): We provide Polycrystalline Diamond (PCD) wafers with controlled boron doping levels, ensuring the low resistivity (e.g., 0.075 Ω·cm) and high conductivity necessary for electrochemical oxidation studies. Our BDD material is ideal for scaling up the production of robust biosensors.
- Ultra-Smooth PCD Substrates: For applications requiring superior surface quality for consistent biomolecule immobilization (like GMP/DNA), 6CCVD offers inch-size PCD wafers polished to an industry-leading roughness of Ra < 5nm.
Customization Potential
Section titled âCustomization PotentialâThe paper utilized a small, 3 mm diameter BDDE. 6CCVD specializes in providing custom geometries and integration features critical for device manufacturing.
| Research Requirement | 6CCVD Capability | Benefit to Researcher |
|---|---|---|
| Small Diameter Electrode (3 mm) | Precision laser cutting and dicing services. | Supply of custom-sized discs or arrays, ready for integration into PEEK or custom electrode bodies. |
| High Surface Quality for Immobilization | Polishing services down to Ra < 1nm (SCD) or Ra < 5nm (PCD). | Ensures optimal, uniform attachment of GMP/DNA layers, improving sensor sensitivity and reproducibility. |
| Need for Electrical Contact | Internal metalization capability (Au, Pt, Ti, W, Cu). | Provides robust, low-resistance electrical contacts (e.g., Ti/Pt/Au stacks) for reliable connection to potentiostats/galvanostats. |
| Scaling Up Production | Plates/wafers available up to 125mm (PCD). | Enables high-throughput manufacturing of BDDE arrays for commercial environmental monitoring systems. |
Engineering Support
Section titled âEngineering SupportâThe development of novel electrochemical biosensors requires deep expertise in material science and surface chemistry.
- Doping Optimization: 6CCVDâs in-house PhD team can assist researchers in optimizing the boron doping concentration and profile to fine-tune the electrodeâs potential window and charge transfer kinetics for specific environmental analytical chemistry projects.
- Surface Termination: We offer tailored surface termination (e.g., hydrogen or oxygen termination) to enhance the selectivity and stability of biomolecule attachment, crucial for improving the performance metrics (ÎIrel) observed in this study.
- Global Logistics: We ensure reliable, global shipping (DDU default, DDP available) of sensitive diamond materials, supporting international research collaborations.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Abstract Alachlor (ALA) has been widely used in agriculture and may act as a carcinogen and an environmental estrogen. The present work deals with chemical modification of boron-doped diamond electrode (BDDE) by guanosine monophosphate (GMP) and its study in the presence of ALA. Cyclic voltammetry and electrochemical impedance spektroscopy in the presence of the redox indicator 1 Ă 10 -3 mol/L [Fe(CN)6] 3- / 4- together with differential pulse voltammetry of the nucleotide base were explored to test effects of GMP immobilization time, the pesticide concentrations and incubation time in the pesticide solution. It was found that GMP layer on the BDDE surface is distorted after incubation in the ALA solution.