Preparation of boron-doped diamond microelectrodes to determine the distribution size of platinum nanoparticles using current transient method
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2023-06-29 |
| Journal | Environmental and Materials |
| Authors | T. A. Ivandini Aliyah, Reza Rizqi Nurhidayat, Afiten R. Sanjaya, Rahmat Wibowo, Yasuaki Einaga |
| Institutions | University of Indonesia, Keio University |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: BDD Microelectrodes for Nanoparticle Sizing
Section titled âTechnical Documentation & Analysis: BDD Microelectrodes for Nanoparticle SizingâThis document analyzes the research paper âPreparation of boron-doped diamond microelectrodes to determine the distribution size of platinum nanoparticles using current transient methodâ and aligns its findings with the advanced material solutions offered by 6CCVD.
Executive Summary
Section titled âExecutive SummaryâThe research successfully validates Boron-Doped Diamond (BDD) microelectrodes as a superior platform for high-sensitivity electrochemical analysis, specifically for screening the size distribution of Platinum Nanoparticles (Pt NPs).
- Material Achievement: Polycrystalline BDD microelectrodes were synthesized via Microwave Plasma-Assisted Chemical Vapor Deposition (MPACVD) on 25 ”m tungsten needles, achieving an average crystal size of ~5 ”m.
- Performance Superiority: BDD electrodes exhibited significantly lower background current and noise (0.15 nA) compared to traditional Au microelectrodes (~1 nA), confirming the materialâs excellent stability and chemical inertness.
- Application Validation: Chronoamperometry (CA) measurements successfully correlated current transient amplitudes with Pt NP size distribution (average diameters 4.46 nm and 4.78 nm, determined by TEM).
- Mechanism: The low noise and stable current transients of BDD are ideal for observing single nanoparticle collision events, which amplify the electrocatalytic oxidation of hydrazine.
- Material Quality Confirmation: Raman spectroscopy confirmed high-quality diamond (C-C spÂł bonds) and the absence of graphitic or amorphous carbon (no peak at 1500 cm-1), ensuring a wide potential window.
- Core Value Proposition: BDD microelectrodes are highly promising for developing affordable, rapid, and accurate screening methods for nanoparticle size distribution in complex chemical environments.
Technical Specifications
Section titled âTechnical SpecificationsâHard data extracted from the research paper detailing material properties and electrochemical performance.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Microelectrode Substrate Diameter | 25 | ”m | Tungsten needle used for BDD growth |
| BDD Average Crystal Size | ~5 | ”m | Size of deposited polycrystalline diamond particles |
| MPACVD Plasma Power | 2500 | W | Power used during BDD film growth |
| MPACVD Growth Time | 10 | h | Duration of BDD deposition |
| Precursor Solution Ratio | 50:4 | v/v | Acetone : Trimethoxyborane ratio |
| BDD Microelectrode Noise Level (CA) | 0.15 | nA | Significantly lower than Au/Pt electrodes |
| Au Microelectrode Noise Level (CA) | ~1 | nA | Comparison electrode performance |
| Pt NP Average Diameter (90 mM NaBH4) | 4.46 | nm | Determined by TEM |
| Pt NP Average Diameter (60 mM NaBH4) | 4.78 | nm | Determined by TEM |
| BDD Transient Current Response (3.45 nm NP) | ~5 | nA | Correlated current transient amplitude |
| Au Transient Current Response (3.45 nm NP) | ~8 | nA | Comparison current transient amplitude |
| Electrolyte Solution | 15 mM Hydrazine in 50 mM PBS | pH 7.4 | Used for electrocatalytic amplification |
| Applied Potential (CA) | +0.4 | V | vs. Ag/AgCl reference electrode |
Key Methodologies
Section titled âKey MethodologiesâA concise summary of the BDD microelectrode fabrication and testing protocol.
- Substrate Seeding: Tungsten needles (20 ”m diameter) were ultrasonicated for 1.5 h in a suspension of nanodiamond particles in 2-propanol to prepare the surface for growth.
- BDD Deposition: Polycrystalline BDD film was grown using Microwave Plasma-Assisted Chemical Vapor Deposition (MPACVD) at 2500 W for 10 hours. The precursor solution was a 50:4 (v/v) mixture of acetone and trimethoxyborane.
- Electrode Insulation: The BDD-coated needle was insulated by filling a pre-pulled glass capillary and packed with epoxy, followed by curing at 60 °C.
- Material Characterization:
- Raman spectroscopy confirmed the diamond structure (C-C spÂł peak at 1300 cm-1) and the absence of spÂČ carbon.
- XPS confirmed surface termination, showing C-H, C-O, and O-H bonds.
- SEM confirmed the electrode diameter (~25 ”m) and particle size (~5 ”m).
- Pt NP Synthesis: Pt nanoparticles were synthesized via the reduction of H2PtCl6 using NaBH4, stabilized by citric acid as a capping agent.
- Electrochemical Measurement: Chronoamperometry (CA) was performed in a three-electrode cell at +0.4 V (vs. Ag/AgCl) in 15 mM hydrazine/PBS solution to measure current transients resulting from single Pt NP collisions.
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & Capabilitiesâ6CCVD specializes in providing the high-purity, custom-engineered diamond materials required to replicate and advance this high-sensitivity electrochemical research. Our MPCVD BDD products offer the stability and low noise floor essential for single-entity electrochemistry.
| Research Requirement | 6CCVD Solution & Capability | Technical Advantage |
|---|---|---|
| High-Purity Boron-Doped Diamond (BDD) | Heavy Boron Doped PCD Wafers/Plates. 6CCVD supplies high-quality Polycrystalline Diamond (PCD) and Single Crystal Diamond (SCD) doped with Boron, ensuring the necessary conductivity and chemical inertness for electrochemical sensing. | Guarantees the low background current and wide potential window required for high signal-to-noise ratio in single nanoparticle collision experiments (0.15 nA noise floor). |
| Custom Microelectrode Fabrication | Precision Laser Cutting and Etching Services. While the paper used a 25 ”m needle, 6CCVD can supply BDD films on custom substrates or provide precision-cut BDD plates/wafers with features down to micro-scale dimensions. | Enables the creation of reproducible Ultramicroelectrodes (UMEs) and microelectrode arrays, facilitating the scaling and integration of this NP sizing technique. |
| Large-Area BDD Substrates | PCD Wafers up to 125 mm Diameter. For transitioning research into commercial sensor platforms, 6CCVD offers large-area BDD substrates suitable for high-volume manufacturing and integration into microfluidic systems. | Supports industrial scaling of the nanoparticle screening method beyond laboratory-scale tungsten needles. |
| Surface Quality Control | Ultra-Smooth Polishing (Ra < 5 nm for PCD) and Custom Termination. We offer precise control over surface finish and termination (e.g., H-terminated or O-terminated) to optimize the electrocatalytic properties and minimize non-diamond carbon (spÂČ) content. | Minimizes surface adsorption and maximizes the stability of the BDD electrode, ensuring reproducible current transients and long operational life. |
| Integrated Metal Contacts | In-House Metalization Services (Au, Pt, Ti, W, Cu). 6CCVD can deposit the necessary metal contacts (e.g., Au or Pt for comparison studies, or Ti/W adhesion layers) directly onto BDD substrates. | Streamlines the fabrication process for complex sensor architectures, eliminating the need for external metal deposition steps. |
Engineering Support
Section titled âEngineering Supportâ6CCVDâs in-house team of PhD material scientists and engineers can assist researchers and developers in selecting the optimal BDD material specifications (doping concentration, thickness, and surface termination) for high-sensitivity electrochemical applications, including single nanoparticle collision studies and hydrazine oxidation projects.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Boron-doped diamond (BDD) microelectrodes were prepared to investigate the correlation of hydrazine oxidation current responses with Pt nanoparticle (Pt NP) size distribution. The BDD film was grown on the surface of a tungsten needle with a diameter of 25 ”m. An average particle size of around 5 ”m BDD crystalline was successfully synthesized using a microwave plasma-assisted chemical vapor deposition technique. The Raman spectrum confirmed the presence of diamond formation as indicated by peaks corresponding to C-C sp3 bonds, while X-ray photoelectron spectroscopy spectrum showed the presence of C-H and C-OH bonds on the surface of the BDD microelectrode. Meanwhile the Pt nanoparticles was synthesized through reduction reaction of PtCl62- solution using NaBH4 with citric acid as the capping agent. Particles size between 4.46 to 4.78 nm were observed by using TEM measurements. The BDD microelectrodes were utilized to investigate the relationship between Pt nanoparticle size distribution and the current generated from the oxidation reaction of 15 mM hydrazine in a 50 mM phosphate buffer solution pH 7.4 in the presence of 1.0 mL nanoparticle solutions. A current range of 5 and 6 nA with a noise level of 0.15 nA was observed showing a good correlation with the particle sizes of Pt NPs. Comparison was also performed with the measurements using Au microelectrodes, indicated that the prepared BDD microelectrodes is promising for the measurements of nanoparticle sizes distribution, especially Pt NPs.