Sonochemical and sustainable synthesis of graphene-gold (G-Au) nanocomposites for enzymeless and selective electrochemical detection of nitric oxide

• Published in: Biosensors & bioelectronics Vol. 87; pp. 622 - 629
• Main Authors: Geetha Bai, Renu, Muthoosamy, Kasturi, Zhou, Meifang, Ashokkumar, Muthupandian, Huang, Nay Ming, Manickam, Sivakumar
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 15.01.2017
• Subjects: Biomarkers; Cancer; Catalysis; Electrochemical analysis; Electrochemical sensor; Electrochemical Techniques - instrumentation; Electrochemical Techniques - methods; Electrodes; Equipment Design; Gold; Gold - chemistry; Gold nanoparticles; Graphene; Graphite - chemistry; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Nanocomposite; Nanocomposites; Nanocomposites - chemistry; Nanocomposites - ultrastructure; Nanoparticles; Nanotechnology - instrumentation; Nanotechnology - methods; Nitric oxide; Nitric Oxide - analysis; Sonication - instrumentation; Sonication - methods; Sonochemical; Nanocomposite; Sonochemical; Electrochemical sensor; Graphene; Gold nanoparticles; Nitric oxide
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2016.09.003

In this study, a sonochemical approach was utilised for the development of graphene-gold (G-Au) nanocomposite. Through the sonochemical method, simultaneous exfoliation of graphite and the reduction of gold chloride occurs to produce highly crystalline G-Au nanocomposite. The in situ growth of gold nanoparticles (AuNPs) took place on the surface of exfoliated few-layer graphene sheets. The G-Au nanocomposite was characterised by UV–vis, XRD, FTIR, TEM, XPS and Raman spectroscopy techniques. This G-Au nanocomposite was used to modify glassy carbon electrode (GCE) to fabricate an electrochemical sensor for the selective detection of nitric oxide (NO), a critical cancer biomarker. G-Au modified GCE exhibited an enhanced electrocatalytic response towards the oxidation of NO as compared to other control electrodes. The electrochemical detection of NO was investigated by linear sweep voltammetry analysis, utilising the G-Au modified GCE in a linear range of 10–5000μM which exhibited a limit of detection of 0.04μM (S/N=3). Furthermore, this enzyme-free G-Au/GCE exhibited an excellent selectivity towards NO in the presence of interferences. The synergistic effect of graphene and AuNPs, which facilitated exceptional electron-transfer processes between the electrolyte and the GCE thereby improving the sensing performance of the fabricated G-Au modified electrode with stable and reproducible responses. This G-Au nanocomposite introduces a new electrode material in the sensitive and selective detection of NO, a prominent biomarker of cancer. [Display omitted] •A novel sonochemical approach to synthesise G-Au nanocomposite.•Ultrasound for the exfoliation of graphite and the reduction of gold chloride simultaneously.•Faster reaction time (<1h), modest refining procedure and no harmful by-products.•Excellent electrocatalytic performance towards NO detection with LOD value 0.04 µM.•Economical, real time enzymeless sensor for cancer biomarker detection.