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

Coral Salvo-Comino,Francois Bessueille,Sylvain Minot,Madjid Arab,Ilhem Rassas,Nicole Jaffrezic-Renault,Maria Luz Rodriguez-Mendez,Virginie Chevallier,Abdelhamid Errachid

doi:10.3390/ma13030688

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.

Highlights

Due to the advantages that antioxidants offer to health—protecting cells from free radical damage, among others—it is of special interest to include antioxidants, present in food and beverages, in diets.One class of biological antioxidants are phenols and polyphenols, as they can inhibit the oxidation of lipoproteins that protect from cardiovascular illness and cancer [1,2]
The aim of this research was to combine the electrocatalytic properties of nanomaterials, multiwalled carbon nanotubes (MWCNT) decorated with AuNP, and their encapsulation in the polymeric matrix of CS, to increase electron transfer in the molecular imprinted polymers (MIP) film
Boron-doped diamond electrodes were provided by NEOCOAT company (La Chaux-de-Fonds, Switzerland). 300 nm thick polycrystalline boron-doped diamond with boron concentration higher than 7000–8000 ppm was grown by MPECVD on a highly doped silicon substrate

Summary

Introduction

Due to the advantages that antioxidants offer to health—protecting cells from free radical damage, among others—it is of special interest to include antioxidants, present in food and beverages, in diets.One class of biological antioxidants are phenols and polyphenols, as they can inhibit the oxidation of lipoproteins that protect from cardiovascular illness and cancer [1,2]. Due to the advantages that antioxidants offer to health—protecting cells from free radical damage, among others—it is of special interest to include antioxidants, present in food and beverages, in diets. Materials 2020, 13, 688 detection in the food industry is based on electrochemical biosensors and sensors. The detection of phenolic compounds is of special importance in the wine industry due to the need to guarantee the organoleptic properties of each kind of wine [7]. The non-enzymatic electrochemical detection of catechol has been improved based on different electroactive layers [8,9], where the thinness of this film can be controlled through different deposition techniques, such as electrodeposition [10], layer by layer [11], Langmuir–Blodgett [12], and spin-coating [13] among others

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