Electrochemical method for point-of-care determination of ciprofloxacin using boron-doped diamond electrode
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2016-10-01 |
| Journal | Acta Chimica Slovaca |
| Authors | KristĂna CinkovĂĄ, Dana AndrejÄĂĄkovĂĄ, ÄčubomĂĆÌ Ć vorc |
| Institutions | Czech Academy of Sciences, Institute of Analytical Chemistry, Slovak University of Technology in Bratislava |
| Citations | 21 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Boron-Doped Diamond for Ciprofloxacin Sensing
Section titled âTechnical Documentation & Analysis: Boron-Doped Diamond for Ciprofloxacin SensingâExecutive Summary
Section titled âExecutive SummaryâThis paper validates the use of a Boron-Doped Diamond (BDD) electrode as a highly effective, modification-free electrochemical sensor for the rapid, point-of-care determination of the antibiotic ciprofloxacin.
- High Performance Material: Boron-Doped Diamond (BDD) demonstrated notable stability and resistance to fouling, crucial for robust analytical measurements in complex matrices (urine, pharmaceuticals).
- Optimal Sensitivity: Utilizing Differential Pulse Voltammetry (DPV), the method achieved a low detection limit (LOD) of 6.0 x 10-7 mol L-1, suitable for pharmaceutical quality control and biological sample monitoring.
- Excellent Linearity: The calibration curve showed high linearity (Coefficient of Determination R2 = 0.997) over a wide concentration range, confirming the methodâs reliability.
- Method Simplicity: The approach offers a rapid, cost-effective alternative to expensive, time-consuming separation and spectral methods (HPLC, LC).
- Diffusion-Controlled Reaction: The irreversible oxidation of ciprofloxacin at +1.6 V vs. Ag/AgCl was confirmed to be a diffusion-controlled process, simplifying electrode kinetics analysis.
- Validated Application: Successful determination of ciprofloxacin content in commercial pharmaceutical tablets (CiprinolÂź 500) and spiked human urine samples, with satisfactory recovery rates (88.4% to 121.2%).
- âGreenâ Sensor Technology: The study underscores the benefits of BDD as a stable, biocompatible, and high-performance âgreenâ electrochemical sensor platform.
Technical Specifications
Section titled âTechnical SpecificationsâThe following key analytical parameters were extracted from the optimized Differential Pulse Voltammetry (DPV) procedure using the BDD working electrode (1000 ppm B doping).
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Electrode Material | Boron-Doped Diamond (BDD) | N/A | Working Electrode |
| Boron Doping Level | 1000 | ppm | Manufacturer specified |
| Electrochemical Technique | DPV | N/A | Optimized method |
| Peak Potential (Ep) | +1.35 (DPV) / +1.6 (CV) | V vs. Ag/AgCl | Ciprofloxacin Oxidation Peak |
| Supporting Electrolyte | Britton-Robinson Buffer | N/A | Optimal pH 4 |
| Modulation Amplitude | 60 | mV | Optimized DPV parameter |
| Modulation Time | 50 | ms | Optimized DPV parameter |
| Linear Concentration Range | 0.74 - 20.0 x 10-6 | mol L-1 | Calibration range |
| Coefficient of Determination (R2) | 0.997 | N/A | Excellent linearity |
| Detection Limit (LOD) | 6.0 x 10-7 | mol L-1 | Calculated as 3Ï/Slope |
| Repeatability (RSD) | 2.7 | % | For 20 measurements at 4.8 x 10-6 mol L-1 |
| Electrode Reaction Type | Diffusion-controlled | N/A | Confirmed by linear relationship of Ip vs. v1/2 |
Key Methodologies
Section titled âKey MethodologiesâThe experiment employed standard voltammetric techniques, emphasizing rigorous BDD electrode pretreatment to ensure signal stability and reproducibility.
- Chemical Preparation: Britton-Robinson buffer (pH 4) was selected as the optimal supporting electrolyte, prepared by mixing phosphoric, acetic, and boric acids, and adjusted with 0.2 mol L-1 NaOH. Ciprofloxacin stock solutions (1.0 x 10-3 mol L-1) were prepared in double-distilled water.
- Electrode System Setup: A standard three-electrode cell was utilized, consisting of the BDD working electrode (1000 ppm), an Ag/AgCl/3 mol L-1 KCl reference electrode, and a Pt wire counter electrode.
- BDD Surface Pretreatment: Prior to each measurement, the BDD electrode was rinsed with deionized water. The surface was electrochemically pretreated by simple cycling in 0.5 mol L-1 sulfuric acid. This pretreatment was performed using potentials ranging from -2.0 V to +2.0 V and repeated (typically 10 cycles) until a stable signal was achieved.
- Cyclic Voltammetry (CV) Analysis: CV was used to investigate the fundamental electrochemical behavior of ciprofloxacin, confirming the irreversible, diffusion-driven oxidation peak at +1.6 V. Scan rates were varied (0.01 to 0.2 V s-1) to verify diffusion control (Ip proportional to v1/2).
- Differential Pulse Voltammetry (DPV) Optimization: DPV was chosen for quantification due to its higher sensitivity. Optimized parameters were fixed at a modulation amplitude of 60 mV and a modulation time of 50 ms.
- Quantification and Validation: The Standard Addition Method (SA) was used for analysis of complex samples (pharmaceutical tablets and human urine) to mitigate matrix effects. Recovery values were calculated to confirm accuracy.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe research highlights BDD as the superior platform for robust, cost-effective electroanalysis of pharmaceuticals. 6CCVD is uniquely positioned to supply the high-quality, customized diamond materials necessary to replicate and advance this critical research.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend the analytical stability and performance shown in this study, 6CCVD recommends:
- Boron-Doped Diamond (BDD) Wafers and Plates:
- Required Specifications Match: The paper used a 1000 ppm B-doped electrode. 6CCVD offers Heavy Boron Doped Polycrystalline Diamond (PCD BDD) plates with custom doping levels tailored precisely to achieve specific conductivity requirements (e.g., 500 ppm to 10,000 ppm range).
- Advantages: Our BDD exhibits the high stability, low capacitive current, and broad working potential window crucial for the reliable DPV measurements described.
- Optical Grade SCD/PCD:
- For future studies requiring integrated optical analysis or extreme low-noise measurements, our Single Crystal Diamond (SCD) and Optical Grade PCD materials provide industry-leading surface quality (Ra < 1 nm for SCD), ensuring minimal surface defects that could lead to signal drift or fouling.
Customization Potential
Section titled âCustomization Potentialâ6CCVDâs advanced MPCVD and engineering capabilities directly address the needs of sensor development:
| Research Requirement / Extension | 6CCVD Customization Service | Value Proposition |
|---|---|---|
| Non-Standard Dimensions | Custom plate/wafer dimensions up to 125 mm (PCD). | Supply of larger electrodes or wafers suitable for array fabrication and industrial scaling. |
| Electrode Thickness | Custom deposition control (0.1 ”m to 500 ”m). | Precise control over the active diamond layer thickness, critical for optimizing sensing area and ensuring thermal stability. |
| Integrated Contacts | Custom Metalization (Au, Pt, Pd, Ti, W, Cu). | Fabrication of necessary contact pads (e.g., Ti/Pt/Au stack) directly onto the BDD surface, simplifying integration into packaged electrochemical cells or microfluidic systems. |
| Micro-Array Fabrication | Precision Laser Cutting and Dicing. | Allows researchers to develop integrated micro-sensors or electrode arrays, extending the BDD platform toward miniaturized, multi-analyte point-of-care devices. |
| Surface Finish | High-Grade Polishing (Ra < 5 nm for Inch-size PCD). | Provides optimal surface kinetics and minimizes background current, directly enhancing the low RSD (2.7%) achieved in this paper. |
Engineering Support
Section titled âEngineering SupportâThe successful development of this point-of-care sensor relied heavily on optimizing the chemical and physical parameters of the BDD electrode (doping, pretreatment). 6CCVDâs in-house PhD team specializes in diamond electrochemistry and can provide comprehensive material consultation and optimization assistance for similar pharmaceutical analysis, environmental monitoring, or biological fluid sensing projects. We ensure the delivered material is perfectly matched to the applicationâs required conductivity and surface characteristics.
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For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Abstract This paper presents an electrochemical behavior study and quantification of fluoroquinolone antibiotic ciprofloxacin using boron-doped diamond electrode. Ciprofloxacin provides a diffusion-driven electrode reaction with an irreversible and poorly defined peak at +1.6 V vs . Ag/AgCl electrode in the presence of Britton-Robinson buffer solution pH 4. Applying differential pulse voltammetry (modulation amplitude of 60 mV, modulation time of 50 ms), the calibration curve with high linearity ( R 2 = 0.997) was obtained within the concentration range of (0.74 - 20.0) Ă 10 â6 mol L â1 with the detection limit of 6.0 Ă 10 â7 mol L â1 and repeatability expressed by relative standard deviation of 2.7 % (for 20 measurements). Interference study was performed to explore the selectivity of the elaborated procedure. By analysis of pharmaceutical dosages and model human urine samples, the ciprofloxacin content with the recovery values ranging from 88.4 to 121.2 % were determined. The developed approach using point-of-care electrochemical sensor based on boron-doped diamond material could represent inexpensive analytical alternative to separation methods and could be beneficial in analysis of biological samples and in the quality control in pharmaceutical industry.