Voltammetric Sensor Based on Molecularly Imprinted Chitosan-Carbon Nanotubes Decorated with Gold Nanoparticles Nanocomposite Deposited on Boron-Doped Diamond Electrodes for Catechol Detection

At a Glance

Metadata	Details
Publication Date	2020-02-04
Journal	Materials
Authors	Coral Salvo‐Comino, Ilhem Rassas, Sylvain Minot, François Bessueille, Madjid Arab
Institutions	Centre National de la Recherche Scientifique, Institut des Sciences Analytiques
Citations	38
Analysis	Full AI Review Included

Executive Summary

This technical documentation analyzes the successful development of a highly sensitive, biocompatible electrochemical sensor for catechol detection, leveraging the superior properties of Boron-Doped Diamond (BDD) electrodes.

Core Achievement: A Molecularly Imprinted Polymer (MIP) sensor, utilizing a Chitosan (CS) matrix encapsulating Gold Nanoparticle (AuNP)-decorated Multi-Walled Carbon Nanotubes (MWCNT), was successfully deposited onto a BDD electrode.
Material Specification: The sensor relies on a 300 nm thick polycrystalline BDD film, grown via Microwave Plasma Chemical Vapor Deposition (MPECVD), featuring high boron doping (>7000-8000 ppm) for optimal electroactivity.
Enhanced Performance: The inclusion of the MWCNT/AuNP nanocomposite significantly increased electron transfer and provided a high density of imprinted recognition sites, resulting in a wide dynamic range.
Sensitivity & Selectivity: The sensor demonstrated excellent reproducibility (RSD 4.5%) and high sensitivity, achieving a Limit of Detection (LOD) of 3.6 x 10^-5 M for catechol.
Real-World Application: The sensor proved robust and effective for quantifying catechol in complex matrices, successfully detecting the phenolic compound in a diluted red wine sample.
6CCVD Value Proposition: 6CCVD specializes in providing the high-quality, custom-specified BDD substrates (PCD-BDD) required to replicate and scale this advanced electrochemical sensing technology.

Technical Specifications

The following hard data points were extracted from the research paper detailing the BDD substrate and sensor performance:

Parameter	Value	Unit	Context
BDD Material Type	Polycrystalline	-	Grown by MPECVD
BDD Film Thickness	300	nm	Active layer thickness
Boron Doping Concentration	>7000-8000	ppm	Required for high electroactivity
Working Electrode Area	0.07	cm²	Modified BDD electrode
Limit of Detection (LOD)	3.6 x 10^-5	M	MIP CS-MWCNT/AuNP/BDD sensor
Catechol Dynamic Range	75-1000	µM	Wide detection range achieved
MIP Sensor Reproducibility (RSD)	4.5	%	Measured across three different sensors
CV Scan Rate	100	mV/s	Used for cyclic voltammetry analysis
Electrolyte pH	7.4	-	0.1 M Phosphate Buffered Saline (PBS)
AuNP Diameter	~40	nm	Spherical shape on MWCNT
Charge Transfer Resistance (MIP)	6992	Ω	Measured via Electrochemical Impedance Spectroscopy (EIS)
Catechol Concentration in Wine	170	µM	Deduced concentration in diluted red wine sample

Key Methodologies

The fabrication of the high-performance electrochemical sensor involved precise material synthesis and surface modification steps:

BDD Substrate Preparation: Boron-doped diamond electrodes (10 x 10 x 10 mm) were provided by NEOCOAT. The BDD film was 300 nm thick, polycrystalline, and grown by MPECVD on a highly doped silicon substrate.
Electrode Pretreatment: BDD electrodes were cleaned sequentially using ultrasonication in acetone (10 min), followed by immersion in Piranha solution (H₂SO₄:H₂O₂ = 3:1 v/v proportion) for 5 min, and finally dried under nitrogen flow.
MWCNT/AuNP Composite Synthesis: Multi-walled Carbon Nanotubes (MWCNT) were decorated with spherical Gold Nanoparticles (AuNP) using a modified Turkevitch/Frens method involving ultrasonication and storage for a minimum of 3 days.
CS-MWCNT/AuNP Solution Preparation: The composite was dispersed in a Chitosan (CS) solution (5 mg in 10 mL of 1% vol. acetic acid). Cross-linking was performed using glutaraldehyde (25% vol.) at pH 9, followed by heating and centrifugation.
MIP Film Deposition: The final CS-MWCNT/AuNP solution (1.5 mg/mL CS, 0.1 M catechol template) was deposited onto the pretreated BDD electrode surface via drop-casting.
Template Removal: The catechol template molecule was eluted from the dried film by stirring the modified electrode in 0.1 M KCl solution for 20 minutes, creating specific recognition cavities (MIP).
Electrochemical Analysis: Sensor performance was characterized using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) in 0.1 M PBS solution (pH 7.4).

6CCVD Solutions & Capabilities

6CCVD is uniquely positioned to supply the critical diamond materials necessary for the replication, optimization, and scaling of this advanced MIP electrochemical sensor technology.

Applicable Materials

The research relies on highly conductive, chemically stable BDD. 6CCVD offers the exact material specifications required:

Polycrystalline Boron-Doped Diamond (PCD-BDD): We supply high-quality PCD-BDD wafers and plates, grown via MPECVD, capable of matching or exceeding the required doping concentration of >7000-8000 ppm for optimal electrochemical performance.
Custom Thickness Control: The paper utilized a 300 nm film. 6CCVD provides precise thickness control for PCD films ranging from 0.1 µm up to 500 µm, allowing researchers to fine-tune the BDD layer for specific charge transfer and stability requirements.
Substrate Options: While the paper used a highly doped Si substrate, 6CCVD can provide BDD films on various substrates or as free-standing plates up to 10 mm thick, depending on the final device architecture.

Customization Potential

To facilitate the integration of the CS-MWCNT/AuNP nanocomposite, 6CCVD offers comprehensive customization services:

Requirement from Paper	6CCVD Customization Service	Technical Advantage
Electrode Dimensions	Custom laser cutting and shaping of plates/wafers up to 125 mm (PCD).	Enables miniaturization and integration into microfluidic or array sensor platforms.
Surface Metalization	In-house deposition of Au, Pt, Ti, Pd, W, or Cu.	Critical for creating robust electrical contacts or enhancing the electrocatalytic interface, complementing the AuNP layer used in this study.
Surface Finish	Polishing services achieving Ra < 5 nm for inch-size PCD.	Ensures a highly uniform surface for reproducible drop-casting and consistent film adsorption of the MIP nanocomposite.
Doping Uniformity	Guaranteed high uniformity of boron incorporation across large wafers.	Essential for manufacturing reproducible sensor arrays and ensuring consistent current density across multiple devices.

Engineering Support

6CCVD’s in-house PhD team provides expert consultation for projects involving electrochemical sensing and biosensors:

Material Selection: Assistance in selecting the optimal diamond grade (SCD vs. PCD) and doping level for specific phenolic detection applications, ensuring maximum sensitivity and stability.
Interface Optimization: Guidance on surface functionalization techniques (e.g., plasma treatment, chemical modification) to improve the adhesion and performance of complex biopolymer films like the CS-MWCNT/AuNP MIP layer.
Scale-Up Strategy: Support for transitioning from laboratory-scale (10x10 mm electrodes) to high-volume manufacturing using 6CCVD’s large-area PCD wafers (up to 125 mm).

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

View Original Abstract

Phenolic compounds such as catechol are present in a wide variety of foods and beverages; they are of great importance due to their antioxidant properties. This research presents the development of a sensitive and biocompatible molecular imprinted sensor for the electrochemical detection of catechol, based on natural biopolymer-electroactive nanocomposites. Gold nanoparticle (AuNP)-decorated multiwalled carbon nanotubes (MWCNT) have been encapsulated in a polymeric chitosan (CS) matrix. This chitosan nanocomposite has been used to develop a molecular imprinted polymers (MIP) in the presence of catechol on a boron-doped diamond (BDD) electrode. The structure of the decorated MWCNT has been studied by TEM, whereas the characterization of the sensor surface has been imaged by AFM, demonstrating the satisfactory adsorption of the film and the adequate coverage of the decorated carbon nanotubes on the electrode surface. The electrochemical response of the sensor has been analyzed by cyclic voltammetry (CV) where excellent reproducibility and repeatability to catechol detection in the range of 0 to 1 mM has been found, with a detection limit of 3.7 × 10−5 M. Finally, the developed sensor was used to detect catechol in a real wine sample.

Tech Support

Original Source

DOI: https://doi.org/10.3390/ma13030688

References

2017 - Electrochemical Sensor for Detection of Polyphenols in Tea and Wine with Differential Pulse Voltammetry and Electrochemical Impedance Spectroscopy Utilizing Tyrosinase and Gold Nanoparticles Decorated Biomembrane [Crossref]
2010 - The use of cyclic voltammetry for wine analysis: Determination of polyphenols and free sulfur dioxide [Crossref]
2003 - Determination of major phenolic compounds in water by reversed-phase liquid chromatography after pre-column derivatization with benzoyl chloride [Crossref]
2006 - Determination of totalcontent of phenolic compounds and their antioxidantactivity in vegetables-evaluation of spectrophotometricmethods [Crossref]
2017 - Selective, sensitive and reliable colorimetric sensor for catechol detection based on anti-aggregation of unmodified gold nanoparticles utilizing boronic acid-diol reaction: optimization by experimental design methodology [Crossref]
2018 - Ionic liquid-based headspace in-tube liquid-phase microextraction coupled with CE for sensitive detection of phenols [Crossref]
2010 - Amperometric biosensor based on a high resolution photopolymer deposited onto a screen-printed electrode for phenolic compounds monitoring in tea infusions [Crossref]
2012 - Multisensor system based on bisphthalocyanine nanowires for the detection of antioxidants [Crossref]
2001 - A Cyclic Voltammetry Method Suitable for Characterizing Antioxidant Properties of Wine and Wine Phenolics [Crossref]
2012 - Study on the polyfurfural film modified glassy carbon electrode and its application in polyphenols determination [Crossref]