Effect of Carbon Layer Thickness on the Electrocatalytic Oxidation of Glucose in a Ni/BDD Composite Electrode

At a Glance

Metadata	Details
Publication Date	2023-08-01
Journal	Molecules
Authors	Hangyu Long, Kui Wen, Cuiyin Liu, Xuezhang Liu, Huawen Hu
Institutions	Foshan University, Jiangxi Science and Technology Normal University
Citations	2
Analysis	Full AI Review Included

Technical Documentation & Analysis: Ni/BDD Composite Electrodes for Glucose Sensing

Reference Paper: Long, H. et al. “Effect of Carbon Layer Thickness on the Electrocatalytic Oxidation of Glucose in a Ni/BDD Composite Electrode.” Molecules 2023, 28, 5798.

Executive Summary

This documentation analyzes the fabrication and performance optimization of high-performance, non-enzymatic glucose sensors utilizing Nickel (Ni) nanoparticles anchored on a Boron-Doped Diamond (BDD) substrate.

Core Achievement: Demonstrated that the electrocatalytic performance of Ni/BDD composite electrodes is critically dependent on the thickness of the precipitated carbon layer formed during thermal catalytic etching.
Material Foundation: Boron-Doped Diamond (BDD) was selected as the stable, high-corrosion-resistance substrate, fabricated via Chemical Vapor Deposition (CVD).
Optimization Method: Controlled Oxygen Plasma Etching (OPE) was employed to systematically reduce the thickness of the graphitic carbon layer encapsulating the Ni nanoparticles.
Optimal Performance: The electrode etched under 200 W OPE exhibited the best results, achieving a sensitivity of 1443.75 µA cm⁻² mM⁻¹ in the low concentration range (0-2 mM).
Detection Limit: The optimal 200 W electrode achieved an ultra-low Limit of Detection (LOD) of 0.5 µM (S/N = 3).
Mechanism: Milder etching (200 W) optimized the carbon layer thickness, enhancing glucose diffusion channels and maximizing the synergistic effect at the Ni/C interface, thereby accelerating the oxidation reaction.
6CCVD Value Proposition: 6CCVD provides the foundational, high-quality BDD substrates and custom metalization services necessary to replicate and scale this advanced electrochemical sensing platform.

Technical Specifications

The following hard data points were extracted from the research paper detailing the fabrication parameters and electrochemical performance of the optimized Ni/BDD electrodes.

Parameter	Value	Unit	Context
Substrate Material	BDD film on P-type Si	N/A	Heavily doped silicon substrate
Substrate Dimensions	4 x 4 x 0.5	mm³	Standard experimental size
BDD Deposition Temperature	750	°C	Hot Filament CVD (HFCVD)
BDD Deposition Pressure	3	kPa	HFCVD process
Ni Film Thickness (Initial)	~20	nm	DC magnetron sputtering
Thermal Treatment Temperature	700	°C	Annealing in H₂ for 30 min
Optimal Etching Power (OPE)	200	W	Oxygen Plasma Etching (5 min duration)
Electrolyte Solution	0.5	M NaOH	Alkaline condition for glucose oxidation
Applied Potential (Amperometry)	0.5	V	Used for steady-state current measurements
Highest Sensitivity (200 W)	1443.75	µA cm⁻² mM⁻¹	Low concentration range (0-2 mM)
Lowest Limit of Detection (LOD)	0.5	µM	Achieved by 200 W electrode (S/N = 3)
Optimal Linear Range	0-12.8	mM	Wide range suitable for biological sensing
Worst Sensitivity (400 W)	706.25	µA cm⁻² mM⁻¹	Low concentration range (0-2 mM)

Key Methodologies

The fabrication of the optimized Ni/BDD composite electrode involved four critical steps, focusing on strong interfacial adhesion and precise surface carbon layer control.

BDD Film Deposition:
- BDD film was grown on P-type heavily doped silicon substrates (4 x 4 x 0.5 mm³) using Hot Filament Chemical Vapor Deposition (HFCVD).
- Gases used: H₂ (49 sccm), CH₄ (1 sccm), and B₂H₆ (0.2 sccm).
- Conditions: 750 °C, 3 kPa, 8 hours.
Ni Film Deposition:
- A nano-thick Ni film (~20 nm) was deposited onto the BDD surface.
- Method: DC magnetron sputtering.
- Conditions: 150 W power, Ar (30 sccm), 0.5 Pa pressure, 20 seconds duration.
Thermal Catalytic Etching (Anchoring & Carbon Precipitation):
- The Ni/BDD sample was annealed in a tubular furnace.
- Conditions: H₂ (100 sccm), 700 °C, 10 kPa pressure, 30 minutes.
- Result: Ni particles embedded into the BDD, forming a stable interface, and a graphitic carbon layer precipitated, encapsulating the Ni nanoparticles.
Surface Carbon Layer Tuning (Oxygen Plasma Etching - OPE):
- OPE was used to precisely remove the precipitated carbon layer.
- Duration: 5 minutes for all etched samples.
- Etching Powers Tested: 200 W (optimal) and 400 W (over-etched).
- Result: The 200 W treatment achieved the ideal carbon layer thickness, maximizing active site exposure and synergistic effects.

6CCVD Solutions & Capabilities

This research validates the use of high-quality Boron-Doped Diamond (BDD) as a superior platform for advanced electrochemical sensors. 6CCVD is uniquely positioned to supply the necessary diamond materials and custom engineering services required to replicate, scale, and extend this high-performance technology.

Applicable Materials

To replicate or extend this high-sensitivity glucose sensor, researchers require highly conductive, stable BDD films.

Primary Material: Heavy Boron-Doped Diamond (BDD) Films.
- 6CCVD provides BDD films grown via MPCVD, offering superior purity and uniformity compared to HFCVD methods.
- Our BDD films are available in thicknesses ranging from 0.1 µm to 500 µm on various substrates (including Si, as used in this study).
Surface Quality: Polished SCD/PCD/BDD.
- While the paper used etching, a highly polished starting surface (Ra < 1 nm for SCD, < 5 nm for PCD) ensures consistent initial conditions for subsequent sputtering and thermal treatments.

Customization Potential

The success of this research hinges on precise control over material dimensions, film thickness, and interfacial layers. 6CCVD offers comprehensive customization capabilities to meet these exact requirements.

Research Requirement	6CCVD Customization Capability	Impact on Research Extension
Substrate Size & Shape	Custom Dimensions up to 125 mm: We supply BDD plates/wafers up to 125 mm in diameter, or custom laser-cut parts (e.g., 4 x 4 mm³ electrodes).	Enables direct scaling from lab-bench prototypes to commercial-scale devices or integration into microfluidic systems.
Metal Catalyst Layer	Custom Metalization Services: Internal capability for depositing thin films of Au, Pt, Pd, Ti, W, Cu, and Ni (via sputtering or evaporation).	Allows for precise control of the initial Ni film thickness (20 nm used here) and testing of alternative catalysts (e.g., Au-Ni/BDD, Ref. [61]) to further optimize glucose sensing.
Diamond Thickness	Precise Thickness Control: SCD/PCD/BDD films available from 0.1 µm to 500 µm, and substrates up to 10 mm thick.	Supports optimization studies on the effect of BDD film thickness on charge transfer kinetics and thermal stability during the 700 °C annealing step.
Surface Termination	Engineering Support for Surface Preparation: We can provide BDD films with specific surface terminations (e.g., oxygen or hydrogen) to modulate the initial surface energy and reactivity prior to Ni loading.	Crucial for controlling the nucleation and subsequent precipitation of the carbon layer, potentially simplifying or optimizing the plasma etching step.

Engineering Support

The optimization of the carbon layer thickness (200 W vs. 400 W etching) is a complex surface engineering challenge. 6CCVD’s in-house PhD team specializes in diamond material science and electrochemical applications.

Application Focus: We offer consultation on material selection and surface preparation for similar non-enzymatic electrochemical sensing projects (e.g., detection of dopamine, heavy metals, or other small molecules).
Process Integration: Our team can assist researchers in defining the optimal BDD specifications (doping level, thickness, surface roughness) to ensure compatibility with high-temperature thermal catalytic etching and subsequent plasma processing.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

High-performance non-enzymatic glucose sensor composite electrodes were prepared by loading Ni onto a boron-doped diamond (BDD) film surface through a thermal catalytic etching method. A carbon precipitate with a desired thickness could be formed on the Ni/BDD composite electrode surface by tuning the processing conditions. A systematic study regarding the influence of the precipitated carbon layer thickness on the electrocatalytic oxidation of glucose was conducted. While an oxygen plasma was used to etch the precipitated carbon, Ni/BDD-based composite electrodes with the precipitated carbon layers of different thicknesses could be obtained by controlling the oxygen plasma power. These Ni/BDD electrodes were characterized by SEM microscopies, Raman and XPS spectroscopies, and electrochemical tests. The results showed that the carbon layer thickness exerted a significant impact on the resulting electrocatalytic performance. The electrode etched under 200 W power exhibited the best performance, followed by the untreated electrode and the electrode etched under 400 W power with the worst performance. Specifically, the electrode etched under 200 W was demonstrated to possess the highest sensitivity of 1443.75 μA cm−2 mM−1 and the lowest detection limit of 0.5 μM.

Tech Support

Original Source

DOI: https://doi.org/10.3390/molecules28155798

References

2021 - Electrochemical glucose sensitive device based on graphene supported Co3O4@Ag NWs core-shell nanostructures [Crossref]
2020 - Cu-nanoflower decorated gold nanoparticles-graphene oxide nanofiber as electrochemical biosensor for glucose detection [Crossref]
2020 - Non-enzymatic electrochemical glucose sensors based on polyaniline/reduced-graphene-oxide nanocomposites functionalized with silver nanoparticles [Crossref]
2018 - Inkjet printed flexible non-enzymatic glucose sensor for tear fluid analysis [Crossref]
2019 - Recent advances in two-dimensional transition metal dichalcogenides for biological sensing [Crossref]
2022 - A High-Performance Non-Enzymatic Sensor Based on Nickel Foam Decorated with Co-CdIn2O4 Nanoparticles for Electrochemical Detection of Glucose and Its Application in Human Serum [Crossref]
2019 - Electro-polymerized polyacrylamide nano film grown on a Ni-reduced graphene oxide- polymer composite: A highly selective non-enzymatic electrochemical recognition element for glucose [Crossref]
2014 - Electrocatalysis and electroanalysis of nickel, its oxides, hydroxides and oxyhydroxides toward small molecules [Crossref]
2013 - Highly Sensitive and Selective Nonenzymatic Detection of Glucose Using Three-Dimensional Porous Nickel Nanostructures [Crossref]