2D Hexagonal Boron Nitride (2D-hBN) Explored for the Electrochemical Sensing of Dopamine
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2016-09-23 |
| Journal | Analytical Chemistry |
| Authors | Aamar F. Khan, Dale A. C. Brownson, Edward P. Randviir, Graham C. Smith, Craig E. Banks |
| Institutions | University of Chester, Manchester Metropolitan University |
| Citations | 196 |
| Analysis | Full AI Review Included |
6CCVD Technical Documentation: 2D Hexagonal Boron Nitride (2D-hBN) for Dopamine Sensing
Section titled ā6CCVD Technical Documentation: 2D Hexagonal Boron Nitride (2D-hBN) for Dopamine SensingāExecutive Summary
Section titled āExecutive SummaryāThis research paper explores the performance of crystalline 2D hexagonal Boron Nitride (2D-hBN) nanosheets as a novel electrocatalyst for the highly selective detection of dopamine (DA) in the presence of common interferents.
- Core Achievement: Demonstrated effective electrocatalytic activity of 2D-hBN modified electrodes toward the oxidation and sensing of DA.
- Substrate Dependence: The electrocatalytic response was found to be critically dependent on the interaction between the 2D-hBN modifier and the underlying carbon substrate (Glassy Carbon, SPE, Boron-Doped Diamond (BDD)).
- Optimal Configuration: Modification of rough Screen-Printed Graphite Electrodes (SPEs) with 2D-hBN resulted in the most beneficial response, decreasing the DA oxidation potential by up to 90 mV.
- Interferent Resolution: The modified SPE achieved simultaneous detection and improved resolution of DA and Uric Acid (UA), with peak separations reaching ~70 mV at pH 5.0.
- Analytical Sensitivity: The 2D-hBN modified SPE achieved a competitive Limit of Detection (LOD) for DA (in the presence of UA) of 0.65 ĀµM.
- BDD Benchmark Role: Boron-Doped Diamond (BDD) electrodes were utilized as stable, high-potential benchmark platforms, confirming the expected chemically inert characteristics valuable for high-end electroanalysis.
Technical Specifications
Section titled āTechnical SpecificationsāThe following hard data was extracted from the experimental results and comparative analysis, primarily focusing on Dopamine (DA) detection.
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Dopamine (DA) LOD (hBN/SPE) | 0.65 | ĀµM | In presence of Uric Acid (UA) |
| DA LOD (Unmodified SPE) | 2.73 | ĀµM | In presence of Uric Acid (UA) |
| DA/UA Peak Separation (Optimal) | ~70 | mV | 2D-hBN/SPE at pH 5.0 |
| DA/UA Peak Separation (pH 7.4) | ~50 | mV | 2D-hBN/SPE at pH 7.4 |
| DA/AA Peak Separation (Separate Sol.) | 110 | mV | 2D-hBN/SPE at pH 7.4 |
| DA Oxidation Potential (BDD Benchmark) | +0.45 | V | Highest potential measured (pH 7.4 PBS) |
| DA Oxidation Potential (GC) | +0.31 | V | Lowest potential measured (pH 7.4 PBS) |
| DA Potential Reduction (hBN/SPE) | ~90 | mV | Compared to unmodified SPE |
| BDD Electrode Diameter | 3 | mm | Commercial size utilized |
| 2D-hBN Mass Coverage Range | 108 to 324 | ng | Optimization study |
| Scan Rate (CV) | 100 | mV s-1 | Standard measurements |
Key Methodologies
Section titled āKey MethodologiesāThe following is an ordered summary of the preparation and execution parameters utilized for the electrochemical experiments:
- Chemical Purity: All solutions were prepared using deionized water (resistivity not less than 18.2 MĪ© cm) and vigorously degassed with high purity, oxygen-free nitrogen.
- Electrode Configuration: A conventional three-electrode system was employed, featuring a Platinum wire counter electrode and a Saturated Calomel Electrode (SCE) reference electrode.
- Working Electrodes: Commercial 3 mm diameter Glassy Carbon (GC), Screen-Printed Graphite Electrodes (SPE), and Boron-Doped Diamond (BDD) were used as supporting platforms.
- BDD/GC Pre-treatment: GC and BDD electrodes were meticulously polished using 1 and 1/4 Āµm Kemet diamond spray to remove surface contaminants before modification.
- Modifier Solution: Pristine 2D-hBN nanosheets (Boron Nitride Pristine Flakes) were dispersed in ethanol at a concentration of 5.4 mg L-1.
- Surface Modification: Electrodes were modified by drop-casting specific aliquots of the 2D-hBN solution onto the surface, followed by curing for 30 minutes at ambient temperature to evaporate the ethanol.
- Electrolyte: Experiments were conducted primarily in pH 7.4 Phosphate Buffer Solution (PBS) and pH 5.0 Acetate Buffer Solution.
- Measurement Techniques: Electrochemical detection relied on both Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) (E-pulse: 20 mV; t-pulse: 200 ms; equivalent scan rate: 10 mV s-1).
6CCVD Solutions & Capabilities
Section titled ā6CCVD Solutions & CapabilitiesāThis research highlights the continued necessity of Boron-Doped Diamond (BDD) as a reliable and chemically inert platform for benchmarking new 2D material electrocatalysts. 6CCVD is uniquely positioned to supply the high-quality BDD and SCD substrates required to replicate, extend, and industrialize this foundational research in neuromolecular sensing.
| Research Requirement / Challenge | 6CCVD Solution & Capability | Core Value Proposition |
|---|---|---|
| BDD Substrate Supply | Heavy Boron-Doped Diamond (BDD) substrates optimized for electroanalysis, ensuring a wide potential window and extreme stability, crucial for high-voltage applications where GC/SPE foul rapidly. | Guaranteed material purity and reproducible doping profiles for reliable electrochemical benchmarking. |
| Custom Electrode Dimensions | Production of BDD/SCD wafers up to 125 mm diameter. Precision laser cutting services to produce application-ready 3 mm diameter or custom-shaped electrodes (as used in the paper). | Accelerate R&D timelines by supplying ready-to-use, application-specific electrode geometries. |
| Surface Morphology Control | Offering polishing services down to Ra < 1 nm for SCD and Ra < 5 nm for inch-sized PCD. | Critical for substrate interaction studies where roughness (Ra) dictates the adherence and performance of 2D modifiers (like hBN). We ensure highly controllable surface inputs. |
| Alternative Substrates | Provision of high-grade Optical or Electronic Grade Single Crystal Diamond (SCD) for studies requiring unparalleled purity and minimal background currents, serving as superior inert platforms for 2D hBN deposition. | Minimize substrate interference and maximize signal-to-noise ratio in advanced sensor fabrication experiments. |
| Metalization Requirements | In-house capability for custom metal contacts (Au, Pt, Pd, Ti, W, Cu). | Essential for integrating modified diamond substrates into practical sensor devices and connecting to external circuitry. |
Engineering Support
Section titled āEngineering Supportā6CCVDās in-house PhD material science team possesses deep expertise in MPCVD diamond synthesis and surface functionalization. We can assist engineers and scientists with material selection, doping level optimization, and polishing strategies for projects focused on neuromolecular sensing (dopamine, ascorbic acid, uric acid) or the integration of novel 2D materials (hBN, MoS2, graphene) onto diamond platforms.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Crystalline 2D hexagonal boron nitride (2D-hBN) nanosheets are explored as a potential electrocatalyst toward the electroanalytical sensing of dopamine (DA). The 2D-hBN nanosheets are electrically wired via a drop-casting modification process onto a range of commercially available carbon supporting electrodes, including glassy carbon (GC), boron-doped diamond (BDD), and screen-printed graphitic electrodes (SPEs). 2D-hBN has not previously been explored toward the electrochemical detection/electrochemical sensing of DA. We critically evaluate the potential electrocatalytic performance of 2D-hBN modified electrodes, the effect of supporting carbon electrode platforms, and the effect of āmass coverageā (which is commonly neglected in the 2D material literature) toward the detection of DA. The response of 2D-hBN modified electrodes is found to be largely dependent upon the interaction between 2D-hBN and the underlying supporting electrode material. For example, in the case of SPEs, modification with 2D-hBN (324 ng) improves the electrochemical response, decreasing the electrochemical oxidation potential of DA by ā¼90 mV compared to an unmodified SPE. Conversely, modification of a GC electrode with 2D-hBN (324 ng) resulted in an increased oxidation potential of DA by ā¼80 mV when compared to the unmodified electrode. We explore the underlying mechanisms of the aforementioned examples and infer that electrode surface interactions and roughness factors are critical considerations. 2D-hBN is utilized toward the sensing of DA in the presence of the common interferents ascorbic acid (AA) and uric acid (UA). 2D-hBN is found to be an effective electrocatalyst in the simultaneous detection of DA and UA at both pH 5.0 and 7.4. The peak separations/resolution between DA and UA increases by ā¼70 and 50 mV (at pH 5.0 and 7.4, respectively, when utilizing 108 ng of 2D-hBN) compared to unmodified SPEs, with a particularly favorable response evident in pH 5.0, giving rise to a significant increase in the peak current of DA. The limit of detection (3Ļ) is found to correspond to 0.65 Ī¼M for DA in the presence of UA. However, it is not possible to deconvolute the simultaneous detection of DA and AA. The observed electrocatalytic effect at 2D-hBN has not previously been reported in the literature when supported upon carbon or any other electrode. We provide valuable insights into the modifier-substrate interactions of this material, essential for those designing, fabricating, and consequently performing electrochemical experiments utilizing 2D-hBN and related 2D materials.