Micro-band Boron-doped Diamond Electrode in Capillary Electrophoresis for Simultaneous Detection of AMP, ADP, and ATP
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2021-04-13 |
| Journal | International Journal of Technology |
| Authors | Putu Udiyani Prayikaputri, Prastika Krisma Jiwanti, Mochammad Arfin Fardiansyah Nasution, Jarnuzi Gunlazuardi, Endang Saepudin |
| Institutions | University of Indonesia, Airlangga University |
| Citations | 5 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Micro-band Boron-doped Diamond Electrodes
Section titled âTechnical Documentation & Analysis: Micro-band Boron-doped Diamond ElectrodesâExecutive Summary
Section titled âExecutive SummaryâThis research successfully demonstrates the fabrication and application of a highly sensitive micro-band Boron-Doped Diamond (BDD) electrode coupled with Capillary Zone Electrophoresis (CZE) for bioanalytical sensing.
- Material Focus: Polycrystalline Boron-Doped Diamond (BDD) films were synthesized via Microwave Plasma-Assisted Chemical Vapor Deposition (MPCVD), confirming high sp3 crystallinity.
- Novel Geometry: A micro-band electrode geometry was achieved through a lamination (sandwich) technique, resulting in an effective surface area of 1.11 x 10-7 m2.
- High Sensitivity: The micro-band geometry leveraged radial diffusion, providing significantly higher sensitivity and better Limits of Detection (LODs) compared to traditional macro-BDD electrodes.
- Simultaneous Detection: The system successfully achieved simultaneous, well-separated detection of Adenosine Monophosphate (AMP), Adenosine Diphosphate (ADP), and Adenosine Triphosphate (ATP).
- Performance Metrics: LODs were achieved in the low micromolar range (0.004 ”M to 0.011 ”M) for the three adenosine phosphates.
- Real-World Application: The method was validated for complex matrices, successfully analyzing and quantifying spiked adenine, guanine, AMP, ADP, and ATP in human urine samples.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the research detailing the material properties and optimal operational parameters.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| BDD Synthesis Method | MPCVD | - | Polycrystalline film deposition |
| BDD Film Thickness (As-deposited) | 5 | ”m | Average thickness |
| BDD Film Thickness (Micro-band) | ~10 | ”m | Observed in longitudinal SEM section |
| Boron Doping Level (B/C) | 1 | % | Used in methanol solution precursor |
| Effective Electrode Area | 1.11 x 10-7 | m2 | Calculated via Cottrell equation |
| Optimal Detection Potential | +1.0 | V | vs Ag/AgCl, for AP oxidation |
| Optimal Buffer pH | 2.0 | - | Britton-Robinson buffer for highest oxidation current |
| Optimal Separation Voltage | 10 | kV | Capillary Electrophoresis separation |
| LOD (ATP, Micro-band BDD) | 0.011 | ”M | Limit of Detection |
| LOD (AMP, Micro-band BDD) | 0.004 | ”M | Limit of Detection |
| LOD (ADP, Micro-band BDD) | 0.006 | ”M | Limit of Detection |
| Linear Correlation (R2) | 0.997 - 0.999 | - | Across 0.1 mM to 2.0 mM range |
Key Methodologies
Section titled âKey MethodologiesâThe fabrication of the micro-band BDD electrode involved precise material synthesis and post-processing steps critical for achieving the desired electrochemical performance.
- BDD Synthesis (MPCVD): Polycrystalline BDD film was grown on a Si (100) substrate using a Microwave Plasma-Assisted Chemical Vapor Deposition (MPCVD) system. The precursor solution included methanol doped with boron at a 1% B/C ratio.
- Substrate Removal: The BDD film was separated from the Si substrate by immersion in a 1:1 mixture of HF (48%) and HNO3 (60%) for 12 hours, yielding a free-standing BDD film.
- Electrode Preparation: The free-standing BDD film and silicone rubber were cut into 1 cm x 1 cm squares.
- Micro-band Lamination: The BDD film was sandwiched between insulating plates (Teflon and silicone rubber) in the order: Teflon-silicone-BDD-silicone-Teflon. This lamination technique defined the micro-band geometry (4 mm wide exposed area).
- Electrical Contact: A copper wire was inserted into the sandwich structure to provide electrical contact to the BDD film.
- Electrochemical Testing: Cyclic Voltammetry (CV) was performed over a potential range of -1.6 V to +2.0 V. Amperometry was coupled with the CZE system for detection at the optimal potential of +1.0 V.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD is uniquely positioned to supply the advanced BDD materials and custom fabrication services required to replicate, optimize, and scale the high-performance electrochemical sensor demonstrated in this research.
Applicable Materials
Section titled âApplicable MaterialsâThe core material requirement is high-quality, heavily Boron-Doped Diamond (BDD) film suitable for electrochemical detection.
| Research Requirement | 6CCVD Solution | Technical Advantage |
|---|---|---|
| Polycrystalline BDD Film (5 ”m thick) | Heavy Boron-Doped PCD Wafers | We offer PCD films from 0.1 ”m up to 500 ”m thick, allowing precise matching of the 5 ”m requirement. |
| High sp3 Purity | High-Quality MPCVD Synthesis | Our advanced MPCVD reactors ensure minimal sp2 carbon impurities, critical for achieving the wide potential window and low background current characteristic of high-performance BDD. |
| Free-Standing Film | Custom Substrate Removal | We supply BDD films either on standard Si substrates or as free-standing wafers (up to 500 ”m thick), eliminating the need for in-house HF/HNO3 etching by the end-user. |
Customization Potential for Enhanced Performance
Section titled âCustomization Potential for Enhanced PerformanceâThe research noted potential delamination defects in the manually laminated micro-band structure (Figure 3b). 6CCVDâs integrated fabrication capabilities can eliminate these issues and optimize the electrode geometry.
- Precision Geometry: While the paper used 1 cm x 1 cm squares, 6CCVD offers precision laser cutting services to define micro-band or micro-array geometries directly onto the BDD wafer with micron-level accuracy, ensuring consistent, defect-free electrode edges superior to manual lamination.
- Integrated Metalization: The use of a simple copper wire contact is prone to defects. 6CCVD offers in-house metalization services (Ti/Pt/Au, W/Cu, etc.) to deposit robust, low-resistance contact pads directly onto the BDD surface. This ensures reliable electrical contact and simplifies integration into CZE/potentiostat systems.
- Large Format Capability: For scaling up production or creating multi-channel CZE systems, 6CCVD can provide PCD wafers up to 125 mm in diameter, far exceeding the small 1 cm x 1 cm pieces used in the study.
- Polishing: We offer ultra-smooth polishing (Ra < 5 nm for inch-size PCD) to ensure the BDD surface is optimally prepared for subsequent lamination or patterning steps, minimizing surface roughness that can affect electrochemical performance.
Engineering Support
Section titled âEngineering SupportâThe successful application of BDD in complex bioanalytical systems, such as the simultaneous detection of adenosine phosphates in urine, requires specialized material knowledge.
- Application Expertise: 6CCVDâs in-house PhD team specializes in the electrochemical properties of diamond. We offer consultation on optimizing BDD material parameters (doping concentration, surface termination, and thickness) for similar Capillary Electrophoresis (CE) and Amperometric Detection projects.
- Material Selection: We provide expert guidance on selecting the appropriate diamond grade (SCD for ultimate purity/smoothness, or PCD for cost-effective large area coverage) based on the specific sensitivity and stability requirements of the target analyte.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
A micro-band boron-doped diamond (BDD) electrode was prepared by sealing a piece of BDD film with an area of 1.11ÂŽ10-7 m2 between two insulating plates, one Teflon and one silicon rubber, to form sandwich-like layers, so the surface area could be investigated. The micro-band BDD was combined with capillary zone electrophoresis as an electrode for the simultaneous detection of adenosine monophosphate (AMP), adenosine diphosphate (ADP), and adenosine triphosphate (ATP) in a solution. These adenosine phosphates can be separated with a 0.3 m-long fused silica capillary using Britton-Robinson buffers at pH 2.0. Current in the concentration range of 0.1 to 2.0 mM were linear with the limits of detection of 0.004 ?M, 0.006 ?M, and 0.011 ?M for AMP, ADP, and ATP, respectively. A comparison with an unmodified BDD as the detector in the same electrophoresis system showed that the micro-band generated better limits of detection (LODs) than the macroelectrode. This method was successfully applied to human urine samples injected with three adenosine phosphates, as well as adenine and guanine, which can be well-separated with recovery percentages of adenine, guanine, AMP, ADP, and ATP of 99.2%, 102.5%, 107.4%, 107.7%, and 105.4%, respectively.