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

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.

Solid‐State Fabrication of Cu2O/CuO Hydroxide Nanoelectrode Array onto Graphene Paper by Thermal Dewetting for High‐Sensitive Detection of Glucose

“…Notably, the as‐deposited film does not show significant phenomena of aggregation or nucleation characteristic of the early stage of growth of thin metal films. [ 28,29 ]…”

“…In previous papers, we have shown the preparation of electrodes for glucose and fructose determination based on gold nanostructures onto graphene paper (GP). [ 28,29 ] The nanostructures were obtained by two‐step fully dry processes consisting of thermal or laser dewetting of thin films of 1.6 and 8 nm of gold deposited by sputtering. [ 28,29 ] The proposed electrodes exhibited competitive analytical performance with the state of the art concerning both enzymatic and nonenzymatic‐based electrodes, even at very low metal content up to few percent by atomic surface composition.…”

“…[ 28,29 ] The nanostructures were obtained by two‐step fully dry processes consisting of thermal or laser dewetting of thin films of 1.6 and 8 nm of gold deposited by sputtering. [ 28,29 ] The proposed electrodes exhibited competitive analytical performance with the state of the art concerning both enzymatic and nonenzymatic‐based electrodes, even at very low metal content up to few percent by atomic surface composition. The proposed processes are characterized by simplicity and low cost, if compared with high throughput.…”

“…[ 35 ] In previous works, we have emphasized that an approach to enhance the electrocatalytic activity of nanostructures with stable performance is to increase their effective surface area in the form of nanoelectrode array. [ 28,29 ] Then, a further approach to improve the nanostructure electrocatalytic activity consists of the synthesis of them in high‐index crystalline or amorphous phases. [ 36 ]…”

Plasmonic hot carrier injection from single gold nanoparticles into topological insulator Bi2Se3 nanoribbons

“…12,18 In graphene-based devices, hot electron-hole pairs increase local electron densities and generate photocurrents. 19,20 The local manipulation of relativistic quantum states of nanostructures with AuNPs is an emerging research field 8,21,22 and in this fashion, the surface states of Bi 2 Se 3 can be engineered into future device requirements by locally manipulating the electronic band structure in nanostructures. 23 The hot photoinjected electrons interact with the relativistic quantum states of TIs and couple to the surface phonon modes.…”