Multi‐walled Carbon Nanotubes Non‐covalently Functionalized with Polyarginine: A New Alternative for the Construction of Reagentless NAD⁺/Dehydrogenase‐based Ethanol Biosensor

Abstract

This work reports for the first time the development of a reagentless enzymatic amperometric biosensor for ethanol based on the use of a glassy carbon electrode (GCE) modified with multi‐walled carbon nanotubes (MWCNTs) non‐covalently functionalized with polyarginine (Polyarg) as platform for the robust immobilization of alcohol dehydrogenase (ADH) and NAD+. The new strategy allows to obtain an integrated GCE/MWCNTs‐Polyarg/NAD+‐ADH ethanol biosensor with important advantages compared to the existing ethanol biosensors: avoids the external addition of the cofactor for each measurement, ensures a fast and sensitive quantification of ethanol due to the intimate interaction of the components, and allows the detection at considerably lower potentials due to the catalytic activity of the carbon nanostructures. These unique properties have made possible a very efficient ethanol quantification with a sensitivity of (1487±6) μA M−1, detection limit of 0.65 μM, response time of 8 s, and reproducibility of 5.5 % with a very successful application for the quantification of ethanol in different commercial beverages.

A New Highly Sensitive Electrochemical Biosensor for Ethanol Detection Based on Gold Nanoparticles/Reduced Graphene Oxide/Polyallylamine Hydrochloride Nanocomposite

“…Another ethanol based on Au-AgNPs/P(l-Cys)-ERGO/GCE [25] had a working concentration range of approximately two decades based on two linear ranges but had a sensitivity approximately 10 times lower than that of the biosensor developed in this study. While other research groups' ethanol biosensors [10,42] have a lower detection limit compared to the developed biosensors, they lack a wide response range and high sensitivity. Therefore, we believe that the ethanol biosensor based on AuNPs-ERGO-PAH/SPE electrode exhibits good performance by combining high sensitivity, wide working range, and low detection limit.…”

“…Carbon nanomaterials and nanocomposites based on carbon nanotubes [3,5,[10][11][12] or graphene [13][14][15][16][17] have received increased attention in recent years and proved very efficient for detecting NADH. Mediators can catalyze the electrochemical oxidation of coenzymes at a higher efficiency in the presence of nanomaterials [3,5,6,18,19].…”

Screen-Printed Carbon Electrodes Modified with Graphene Oxide for the Design of a Reagent-Free NAD+-Dependent Biosensor Array

“…For this reason, great efforts have been made for the construction of reagent-free systems. Efficient coimmobilization of enzymes, cofactors, and mediators has been described with, for example, functionalized carbon nanotubes, − entrapment in carbon pastes, , membranes, , polypyrrol, , or chitosan films. , …”