Copper-Modified Boron-Doped Diamond (Cu/Bdd) Electrode for the Electrochemical Detection of Paclitaxel and Oxaliplatin in Aqueous Solutions
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2020-01-19 |
| Journal | Revista de Chimie |
| Authors | Sorina-Claudia Negrea, Lidia Ani Diaconu, Valeria Nicorescu, Anamaria Baciu, Aniela Pop |
| Institutions | Gheorghe Asachi Technical University of IaČi, Polytechnic University of TimiÅoara |
| Citations | 3 |
| Analysis | Full AI Review Included |
Executive Summary
Section titled āExecutive SummaryāThis study details the development and characterization of a Copper-Modified Boron-Doped Diamond (Cu/BDD) electrode designed for the rapid and sensitive electrochemical detection of two critical cytostatic drugs: Paclitaxel (PCX) and Oxaliplatin (OXA), in aqueous solutions.
- Core Achievement: Successful modification of a commercial BDD electrode with copper nanoparticles using optimized chronoamperometry (CA) to achieve electrocatalytic activity toward PCX and OXA oxidation.
- Modification Recipe: Optimal copper deposition was achieved at a potential of -0.75 V/SCE for 120 seconds (s) in 0.05 M copper sulphate solution.
- Enhanced Performance: The bare BDD electrode showed no detectable signal for either cytostatic; the Cu/BDD modification enabled clear anodic oxidation peaks in 0.1 M NaOH electrolyte.
- Paclitaxel (PCX) Detection: Achieved superior sensitivity of 5.47 ĀµA/ĀµM via Cyclic Voltammetry (CV) at +0.75 V/SCE, with a low Limit of Detection (LOD) of 0.05 ĀµM.
- Oxaliplatin (OXA) Detection: Achieved a sensitivity of 0.65 ĀµA/ĀµM via CV at +0.6 V/SCE, with an LOD of 2.07 ĀµM.
- Mechanism Insight: Analysis of scan rate dependence for PCX indicated significant involvement of the electrode surface in the oxidation process, suggesting potential fouling issues, which explains why CV yielded better sensitivity than CA for PCX.
- Value Proposition: The modified Cu/BDD electrode offers a simple, fast, and cost-effective platform suitable for monitoring these highly toxic emerging pollutants in environmental samples.
Technical Specifications
Section titled āTechnical Specificationsā| Parameter | Value | Unit | Context |
|---|---|---|---|
| Working Electrode Material | Copper-Modified Boron-Doped Diamond (Cu/BDD) | N/A | Commercial BDD used as substrate |
| BDD Boron Content | ~0.1 | N/A | Commercial electrode specification |
| Supporting Electrolyte | 0.1 M | NaOH | Electrochemical detection medium |
| Cu Deposition Technique | Chronoamperometry (CA) | N/A | Modification method |
| Optimized Cu Deposition Potential (Edep) | -0.75 | V/SCE | Determined using 25 ĀµM Oxaliplatin |
| Optimized Cu Deposition Time (Tdep) | 120 | s | Determined using 25 ĀµM Oxaliplatin |
| Paclitaxel (PCX) Detection (CV) | |||
| PCX Oxidation Potential | +0.75 | V/SCE | Anodic peak potential |
| PCX Sensitivity (CV) | 5.47 | ĀµA/ĀµM | Correlation Coefficient (R): 0.970 |
| PCX Limit of Detection (LOD) | 0.05 | ĀµM | Calculated via CV |
| Oxaliplatin (OXA) Detection (CV) | |||
| OXA Oxidation Potential | +0.6 | V/SCE | Anodic peak potential |
| OXA Sensitivity (CV) | 0.65 | ĀµA/ĀµM | Correlation Coefficient (R): 0.972 |
| OXA Limit of Detection (LOD) | 2.07 | ĀµM | Calculated via CV |
| PCX Sensitivity (CA) | 1.87 | ĀµA/ĀµM | Detection at +0.8 V/SCE (Lower than CV) |
| PCX Limit of Quantitation (LOQ) (CA) | 5.34 | ĀµM | Calculated via CA |
Key Methodologies
Section titled āKey MethodologiesāThe electrochemical modification and detection processes utilized standard three-electrode cell configurations and were optimized using systematic variation of deposition parameters.
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Electrode Pre-treatment:
- Commercial BDD electrodes were stabilized by recording 10 repetitive Cyclic Voltammograms (CV) in the potential range of -1 V to +1 V/SCE.
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Copper Electrodeposition (Chronoamperometry - CA):
- Deposition Solution: 0.05 M copper sulphate (CuSO4).
- Potential Optimization: CA was performed by varying the deposition potential from -0.15 V to -1.2 V/SCE (Time fixed at 60 s). The optimal potential was found to be -0.75 V/SCE.
- Time Optimization: CA was performed by varying the deposition time from 30 s to 150 s (Potential fixed at -0.75 V/SCE). The optimal time was found to be 120 s.
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Morphological Characterization:
- Scanning Electron Microscopy (SEM) was used to compare the bare BDD surface with the Cu/BDD surface, confirming the presence of small, relatively well-distributed copper particles post-modification.
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Electrochemical Detection and Characterization:
- Electrolyte: 0.1 M NaOH.
- Cyclic Voltammetry (CV): Used for initial detection, optimization, and determination of analytical parameters (sensitivity, LOD). CV was also used to study the oxidation mechanism by analyzing the dependence of peak current and potential on the scan rate (v).
- Chronoamperometry (CA): Applied for PCX detection as a potential technique for automated, in-field applications, though results showed lower sensitivity compared to CV, suggesting surface fouling.
Commercial Applications
Section titled āCommercial ApplicationsāThe development of the Cu/BDD sensor addresses critical needs in environmental monitoring and pharmaceutical quality control, particularly concerning highly toxic compounds.
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Environmental Monitoring of Emerging Pollutants (EPs):
- Provides a simple, fast, and cost-effective method for monitoring cytostatic drugs (PCX, OXA) in hospital effluents and municipal wastewater treatment plant discharges.
- Essential for regulatory compliance and assessing environmental risk, as these drugs are highly toxic even at low concentrations.
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Water Quality Control:
- Potential integration into continuous monitoring systems for surface and groundwaters to track the spread of pharmaceutical contaminants.
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Pharmaceutical and Clinical Analysis:
- Rapid electroanalytical tool for quality control and dosage verification of PCX and OXA in pharmaceutical formulations, offering an alternative to slower, more complex chromatographic methods.
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Advanced Sensor Technology:
- The Cu/BDD platform serves as a foundation for developing robust, stable electrochemical sensors for other hazardous substances, leveraging the wide potential window and chemical inertness of BDD combined with the electrocatalytic properties of copper.
View Original Abstract
The aim of this study was to obtain a simple and fast modified electrode for the detection of paclitaxel (PCX) and oxaliplatin (OXA) in aqueous solution. PCX and OXA are some of the most used cytostatic drugs suitable to treat various types of cancer, e.g., ovarian, breast, lung, cervical, pancreatic, Kaposiās sarcoma. The development of an easy method for its determination is required for both the dosage in cancer therapy and due its potential presence in environment and especially, in water samples. Boron doped diamond (BDD) electrode was electrochemically modified with copper (Cu) by chronoamperometry (CA) operated under optimized conditions of -0.75 V/SCE potential level for 120 minutes. Copper-modified boron-doped diamond (Cu/BDD) exhibited the electrocatalytic effect towards the paclitaxel and oxaliplatin oxidation, allowing their detection in 0.1 M NaOH supporting electrolyte. The limiting anodic current was noticed at the potential value of +0.75 V/SCE that increased linearly with PCX concentration, and at the potential value of + 0.6V/SCE for the oxaliplatin. Some mechanical aspects related to the PCX oxidation at Cu/BDD electrode in 0.1 M NaOH supporting electrolyte were determined using cyclic voltammetry (CV) recorded at various scan rates. CV was based on compounds detection and achieved the sensitivity of 0.65 Ī¼A/ĀµM for oxaliplatin and respective, 5.47 Ī¼A/ĀµM for paclitaxel. Keywords: copper, electrochemical detection, modified boron-doped diamond electrode paclitaxel, oxaliplatin