Detection of Cisplatin with Boron‐Doped Diamond Thin‐Film Electrodes Using Flow Injection Analysis and Ion Exclusion Chromatography with Amperometric Detection
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2025-07-01 |
| Journal | Electroanalysis |
| Authors | Aaron Jacobs, Alice W. Njue, Greg M. Swain |
| Institutions | Michigan State University, Egerton University |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Cisplatin Detection using BDD Electrodes
Section titled “Technical Documentation & Analysis: Cisplatin Detection using BDD Electrodes”This document analyzes the research paper “Detection of Cisplatin with Boron-Doped Diamond Thin-Film Electrodes Using Flow Injection Analysis and Ion Exclusion Chromatography with Amperometric Detection” to provide technical specifications and align the findings with 6CCVD’s advanced MPCVD diamond material solutions.
Executive Summary
Section titled “Executive Summary”The research successfully demonstrates the superior performance of Boron-Doped Diamond (BDD) thin-film electrodes for the electrochemical detection of Cisplatin, a critical platinum-based chemotherapy drug.
- Superior Material Performance: BDD electrodes exhibited a significantly larger oxidation peak current and a 5x smaller background current compared to traditional Glassy Carbon (GC) electrodes, enabling highly sensitive detection at high positive potentials (1.5 V vs. Ag/AgCl).
- Simplified Methodology: The BDD material’s intrinsic stability and wide anodic potential window eliminate the need for conventional electrode surface modification or time-consuming pretreatment steps, streamlining the analytical workflow.
- High Sensitivity and Range: The Flow Injection Analysis (FIA-EC) method achieved an experimentally determined Limit of Detection (LOD) of 0.5 µM (S/N=3) and a Linear Dynamic Range (LDR) of 1-100 µM, covering the therapeutically relevant concentration range in human urine.
- Excellent Reproducibility: The BDD response showed high reproducibility, stabilizing to a Relative Standard Deviation (RSD) of 2.7% over 10 consecutive injections of 100 µM Cisplatin.
- Robust Stability: The BDD thin-films maintained high electrochemical activity even after 8 months of ambient laboratory storage, confirming the material’s long-term reliability for commercial applications.
- Complex Matrix Selectivity: Coupling BDD amperometric detection with Ion Exclusion Chromatography (IEC-EC) successfully separated Cisplatin from electrochemically active interferents (like uric acid) found in complex biological samples (human urine).
Technical Specifications
Section titled “Technical Specifications”The following hard data points were extracted from the study detailing the BDD material performance and analytical figures of merit.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Electrode Material | Boron-Doped Diamond (BDD) | Thin-Film | Polycrystalline morphology (100-800 nm crystallites) |
| BDD Thickness | 2-3 | µm | Grown on Si substrate via MPCVD |
| Cisplatin Oxidation Potential (CV) | 1.3 | V | vs. Ag/AgCl (3M KCl) in 0.1 M HClO4 |
| Optimum Detection Potential (FIA-EC) | 1.5 | V | vs. Ag/AgCl (3M KCl) (Maximum Signal-to-Background Ratio) |
| Linear Dynamic Range (LDR) | 1 to 100 | µM | FIA-EC in 0.1 M HClO4 (r2 = 0.988) |
| Limit of Detection (LOD) | 0.5 | µM | Experimentally determined (S/N = 3) |
| Reproducibility (RSD) | 2.7 | % | Over 10 consecutive injections (100 µM Cisplatin) |
| Electron Transfer Process | One | Electron | Determined via Randles-Sevcik analysis |
| Background Current Comparison | 5x Smaller | N/A | BDD vs. Glassy Carbon (GC) at 1.2 V |
| Long-Term Stability | 8 | Months | Ambient storage with no adverse effect on activity (Fe(CN)63-/4- probe) |
Key Methodologies
Section titled “Key Methodologies”The BDD electrodes were synthesized and utilized in the following key steps for Cisplatin detection:
- BDD Thin-Film Synthesis: Boron-doped diamond films were grown on silicon (Si) substrates using Microwave Plasma Chemical Vapor Deposition (MPCVD) in a 1.5 kW reactor.
- Doping and Gas Mixture: The films were heavily doped using a B/C ratio of 5 ppm, achieved by introducing B(OH)3 dissolved in methanol into the H2/CH4 gas plasma.
- Deposition Conditions: Growth occurred at a substrate temperature of 800-900 °C and a pressure of 10-12 Torr, resulting in a nanocrystalline polycrystalline morphology (100-800 nm crystallites).
- Electrode Activation: The BDD electrodes required only cleaning (soaking in distilled IPA followed by ultrapure water rinse) before electrochemical measurements; no conventional electrochemical pretreatment was necessary.
- Flow Injection Analysis (FIA-EC): A BDD working electrode was mounted in a crossflow thin-layer flow cell. The carrier solution (0.1 M HClO4) was delivered at 1 mL/min, and detection was performed amperometrically at 1.5 V.
- Chromatographic Separation (IEC-EC): For complex urine samples, Solid-Phase Extraction (SPE) was used for pretreatment, followed by Ion Exclusion Chromatography (IEC) using a Hi-Plex H column (250 x 4.6 mm) with a 0.1 M H2SO4 mobile phase delivered at 0.3 mL/min at 40 °C.
6CCVD Solutions & Capabilities
Section titled “6CCVD Solutions & Capabilities”The successful detection of Cisplatin relies entirely on the unique electrochemical properties of high-quality, heavily Boron-Doped Diamond (BDD). 6CCVD is uniquely positioned to supply the materials required to replicate, scale, and advance this research into clinical or industrial monitoring applications.
| Research Requirement | 6CCVD Solution & Capability | Technical Advantage for the Customer |
|---|---|---|
| High-Quality BDD Thin-Films | Heavy Boron Doped PCD/SCD: We offer highly conductive BDD materials (both Polycrystalline Diamond (PCD) and Single Crystal Diamond (SCD)) with custom boron doping levels to match or exceed the 5 ppm B/C ratio used in this study. | Guaranteed wide anodic potential window, low noise, and superior chemical stability essential for high-potential oxidation reactions like Cisplatin detection. |
| Custom Film Thickness (2-3 µm) | Precision Thickness Control: 6CCVD provides SCD and PCD films with thickness control from 0.1 µm up to 500 µm, allowing researchers to precisely tune the material properties (e.g., conductivity, Raman penetration depth) for specific sensor designs. | Enables optimization of electrode performance for both voltammetric and hydrodynamic flow cell applications. |
| Integration into Thin-Layer Flow Cells | Custom Dimensions & Laser Cutting: We supply plates and wafers up to 125 mm (PCD) and offer precision laser cutting services to match proprietary flow cell geometries (e.g., rectangular or elliptical gaskets, as suggested for improved resolution). | Ensures seamless integration into existing or novel microfluidic and chromatographic detection systems, minimizing material waste and fabrication time. |
| Robust Electrical Contact & Assembly | Custom Metalization Services: Internal capability to deposit robust electrical contacts (Au, Pt, Ti, W, Cu) onto the BDD surface or the Si substrate backside, critical for reliable current collection in flow cell setups. | Provides a complete, ready-to-use electrode assembly optimized for long-term stability and high-throughput analysis. |
| Material Stability and Consistency | MPCVD Quality Assurance: Our strict quality control protocols ensure exceptional batch-to-batch consistency and long-term material stability, replicating the 8-month stability demonstrated in the paper. | Reduces the need for frequent material validation and replacement, accelerating research timelines and lowering operational costs. |
Engineering Support
Section titled “Engineering Support”6CCVD’s in-house team of PhD material scientists and electrochemists specializes in optimizing diamond properties for analytical applications. We offer consultation services to assist engineers and scientists in selecting the ideal BDD material specifications (doping, thickness, and surface termination) required for similar Cisplatin monitoring, drug detection, or complex biospecimen analysis projects.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
In this work, we investigated the electrochemical behavior of cisplatin at boron‐doped diamond (BDD) thin‐film electrodes using cyclic voltammetry. Flow injection analysis with amperometric detection (FIA‐EC) was used to determine the detection figures of merit. No electrode surface modification or conventional pretreatment was required to activate the BDD electrodes. Diffusion‐limited oxidation of cisplatin, dissolved in 0.1 M HClO 4 , occurred at 1.3 V (vs. Ag/AgCl (3M KCl)) in cyclic voltammetric measurements and at 1.5 V in hydrodynamic voltammetric measurements. FIA‐EC peak current responses were reproducible over 10 consecutive injections of 100 μM cisplatin (relative standard deviation (RSD) = 2.7%) at 1.5 V. The FIA‐EC peak current increased linearly with the cisplatin concentration from 1 to 100 μM (r 2 = 0.988). The minimum detectable concentration was experimentally determined to be 0.5 μM (S/N = 3). Detection of cisplatin in spiked human urine was also investigated using FIA‐EC. Other electrochemically active species present in the urine specimen interfered with cisplatin detection at 1.5 V. These interferents were separated from cisplatin in the spiked urine specimen using solid‐phase extraction (SPE) sample pretreatment and ion exclusion chromatography. Both ultraviolet/visible (UV/Vis) and amperometric detection were compared. Cisplatin was detected 8.9 min after injection using a UV/Vis photodiode array (PDA) and 9.3 min after injection using BDD in an amperometric detector placed in series. Overall, BDD electrodes are a good choice for the reproducible and sensitive electrochemical detection of cisplatin using FIA‐EC or ion exclusion chromatography prior to amperometric detection. Ion exclusion chromatography (IEC) adds selectivity for the electrochemical detection of cisplatin in urine specimens.