Molecularly Imprinted Polypyrrole on Glassy Carbon Electrode Modified with Reduced Graphene Oxide and Gold Nanoparticles for Isoamyl Alcohol Analysis in Fusel Oil

Thiago Mariano,Maísa Beluomini,Nelson Stradiotto

doi:10.21577/0103-5053.20200174

Abstract

A molecularly imprinted electrochemical sensor for determination of isoamyl alcohol was successfully constructed by modifying the glassy carbon electrode (GCE) with gold nanoparticles (AuNPs) and reduced graphene oxide (RGO). The modification of the GCE increased the electron transfer rate and the electrode surface area, which, consequently, made more room available for the formation of the molecularly imprinted polymer (MIP). The development of the MIP on the modified surface was carried out via electropolymerization of the pyrrole in acetate buffer solution in the presence of the target molecule. The MIP-AuNPs-RGO/GCE showed low limit of detection (8.4 × 10-8 mol L-1), satisfactory quantification range, amperometric sensitivity of 1.1 A L mol-1, excellent reproducibility and stability. Even when in the presence of analogous molecules, the sensor exhibited excellent selectivity. These results suggest that the proposed sensor is suitable for the detection of isoamyl alcohol in fusel oil samples.

Highlights

The search for alternative fuels has become inevitable and urgent in the deeply seek to reduce the environmental impacts associated with the use of fossil fuels
To ensure good adhesion and a greater number of active sites for the molecularly imprinted polymer (MIP)-based sensors, reduced graphene oxide (RGO) and AuNPs were electrodeposited on the surface of the glassy carbon electrode (GCE)
amperometric sensitivity (As) the isoamylic alcohol molecules do not present electrochemical activity on GCE and GCE modified with AuNPs-RGO in solution of neutral pH, as shown in Figure S1 (Supplementary Information section), the redox probe was employed in this regard

Summary

Introduction

The search for alternative fuels has become inevitable and urgent in the deeply seek to reduce the environmental impacts associated with the use of fossil fuels In this sense, bioethanol plants and their byproducts have grown significantly in recent years as vital alternatives for lessening the use and even replacing fossil fuels and other harmful chemical substances employed as sources of energy.[1] Bioethanol has proved to be economically useful in addition to being renewable. Bioethanol plants and their byproducts have grown significantly in recent years as vital alternatives for lessening the use and even replacing fossil fuels and other harmful chemical substances employed as sources of energy.[1] Bioethanol has proved to be economically useful in addition to being renewable These are relevant features that explain the fact that it is being internationally marketed to satisfy countries with limited biomass resources. The production of bioethanol generates byproducts such as fusel oil, obtained after fermentation and distillation of biomass, composed mainly of higher alcohols containing three or more carbon atoms, including isoamyl alcohol, isobutanol, propanol, butanol, among others.[2,3] The fact that higher alcohols present in fusel oil are considered natural products provides these alcohols high commercial values

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