Enhanced Performance of GCE/N-Reduced Graphene Oxide-Au Nanocomposite in Dopamine Sensing

Piotr Wiench,Daria Minta,Grażyna Gryglewicz

doi:10.3390/proceedings2019015041

Piotr Wiench, Daria Minta + Show 1 more

Open Access

https://doi.org/10.3390/proceedings2019015041

Copy DOI

Abstract

The reduced graphene oxide (rGO) and nitrogen-reduced graphene oxide (N-rGO) were electrochemically coated with gold nanoparticles and compared as the modifier of a glassy carbon electrode (GCE) for dopamine (DA) electrochemical sensors. The rGO and N-rGO were prepared by reduction of graphene oxide (GO) under hydrothermal conditions. Urea was applied as a nitrogen dopant. The modified GCEs were tested as working electrodes in the electrochemical DA detection in the presence of ascorbic and uric acids. Initially, the working parameters of sensors in a pure dopamine solution were determined. The GCE/N-rGO-Au electrode exhibited a lower limit of detection compared with the GCE/rGO-Au (385 vs. 700 nM). Both sensors had a wide linear range of 1-100 µM and high sensitivity of 0.78 µA/µM for GCE/N-rGO-Au and 1.78 µA/µM for GCE/rGO-Au. The presence of ascorbic and uric acids in the solution resulted in a decrease in the intensity of DA oxidation peak, maintaining acceptable limit of detection. This study showed that the surface modification of the graphene materials with gold nanoparticles allows to obtain satisfactory working parameters of DA sensors. The GCE/N-rGO-Au demonstrated the superior performance in DA sensing due to a homogeneous distribution of gold nanoparticles on the surface of the N-doped graphene material.

Highlights

Nowadays, great scientific efforts are put into the development of electrode materials in order to obtain sensitive, fast and effective dopamine (DA) detection [1]
We demonstrate the influence of Reduced graphene oxide (rGO) and N-doped reduced graphene oxide (N-rGO) modified with AuNPs on the electrochemical DA detection
The DA oxidation-reduction reaction was investigated by CV and differential pulse voltammetry (DPV) which enable to determine the working parameters of the DA sensors (Table 1)

Summary

Introduction

Great scientific efforts are put into the development of electrode materials in order to obtain sensitive, fast and effective dopamine (DA) detection [1]. N-doped reduced graphene oxide (N-rGO) are promising materials in the electrochemical DA detection due to their high electrical conductivity and a high surface to volume ratio [2,3]. The main problem of the DA detection is that DA coexists with uric and ascorbic acids in biological samples [4]. Voltammetric responses of these compounds are similar, it is important to use materials which ensure selective DA detection in the presence of different interferents. Popular, the modification of graphene materials by noble metal nanoparticles, such as gold nanoparticles (AuNPs), results in an enhancement of DA sensing and its selectivity [5]. GCE/N-rGOAu exhibited a lower limit of DA detection when compared to GCE/rGO-Au (385 vs 700 nM)

Materials and Methods

Results and Discussion

Conclusions