Dewetted Gold Nanostructures onto Exfoliated Graphene Paper as High Efficient Glucose Sensor.

Maria Grazia Grimaldi,Francesco Ruffino,Antonino Scandurra,Antonio Terrasi,Maria Censabella

doi:10.3390/nano9121794

Maria Grazia Grimaldi, Francesco Ruffino + Show 3 more

Open Access

https://doi.org/10.3390/nano9121794

Copy DOI

Abstract

Non-enzymatic electrochemical glucose sensing was obtained by gold nanostructures on graphene paper, produced by laser or thermal dewetting of 1.6 and 8 nm-thick Au layers, respectively. Nanosecond laser annealing produces spherical nanoparticles (AuNPs) through the molten-phase dewetting of the gold layer and simultaneous exfoliation of the graphene paper. The resulting composite electrodes were characterized by X-ray photoelectron spectroscopy, cyclic voltammetry, scanning electron microscopy, micro Raman spectroscopy and Rutherford back-scattering spectrometry. Laser dewetted electrode presents graphene nanoplatelets covered by spherical AuNPs. The sizes of AuNPs are in the range of 10–150 nm. A chemical shift in the XPS Au4f core-level of 0.25–0.3 eV suggests the occurrence of AuNPs oxidation, which are characterized by high stability under the electrochemical test. Thermal dewetting leads to electrodes characterized by faceted not oxidized gold structures. Glucose was detected in alkali media at potential of 0.15–0.17 V vs. saturated calomel electrode (SCE), in the concentration range of 2.5μM−30 mM, exploiting the peak corresponding to the oxidation of two electrons. Sensitivity of 1240 µA mM−1 cm−2, detection limit of 2.5 μM and quantifications limit of 20 μM were obtained with 8 nm gold equivalent thickness. The analytical performances are very promising and comparable to the actual state of art concerning gold based electrodes.

Highlights

Glucose biosensors accounts for about 85% of biosensors industry
We reported the non-enzymatic detection of glucose and fructose by gold nanoparticles on graphene paper (GP-annealing produces spherical nanoparticles (AuNPs)) [38]
In order to shed light on the synergistic effects observed in the electro-catalysis of glucose oxidation by gold nanostructures on exfoliated graphene paper, in the present work we investigated deeply the exfoliation phenomena and the surface chemical composition of gold nanostructures obtained by laser or thermal dewetting

Summary

Introduction

Glucose biosensors accounts for about 85% of biosensors industry. reliable and fast monitoring of glucose represents an important analytical tool in many scientific and technology fields such as health [1], food industry [2], environmental assessment [3], and molecular biology [4]. Gold nanostructures onto graphene and carbon nanotubes [31,32] have been constructed by chemical etching [33], electrochemical deposition in hydrophilic gel templates–gelatin and agarose [23], electrochemical etching [34], de-alloying [35], electrochemical deposition using gelatin template [36]. It is pointed out the advantages of carbon materials used as substrate which include the possibility of a variety of chemical functionalization, the absence of interfering metal ions, low cost, high electrical conductivity, and large amplitude of working potential [37]

Methods

Results

Conclusion