Graphene–Gold Nanoparticles Hybrid—Synthesis, Functionalization, and Application in a Electrochemical and Surface-Enhanced Raman Scattering Biosensor

Abstract

Graphene is a single-atom-thick two-dimensional carbon nanosheet with outstanding chemical, electrical, material, optical, and physical properties due to its large surface area, high electron mobility, thermal conductivity, and stability. These extraordinary features of graphene make it a key component for different applications in the biosensing and imaging arena. However, the use of graphene alone is correlated with certain limitations, such as irreversible self-agglomerations, less colloidal stability, poor reliability/repeatability, and non-specificity. The addition of gold nanostructures (AuNS) with graphene produces the graphene–AuNS hybrid nanocomposite which minimizes the limitations as well as providing additional synergistic properties, that is, higher effective surface area, catalytic activity, electrical conductivity, water solubility, and biocompatibility. This review focuses on the fundamental features of graphene, the multidimensional synthesis, and multipurpose applications of graphene–Au nanocomposites. The paper highlights the graphene–gold nanoparticle (AuNP) as the platform substrate for the fabrication of electrochemical and surface-enhanced Raman scattering (SERS)-based biosensors in diverse applications as well as SERS-directed bio-imaging, which is considered as an emerging sector for monitoring stem cell differentiation, and detection and treatment of cancer.

Label‐free Electrochemical Immunosensor for Cardiac Troponin T Based on Exfoliated Graphite Nanoplatelets Decorated with Gold Nanoparticles

“…Second, a kinetic effect is evidenced by a 30 % increase in peak current, when the electrode modified with hybrid material (voltammogram “b”) was compared to xGnP without AuNP‐Hep (voltammogram “a”). These results confirm the advantages of the use of hybrid carbonaceous materials, as reported in the literature .…”

“…The dispersion of metal nanoparticles on carbon materials generates a hybrid nanocomposite, which minimizes limitations, such as irreversible self‐agglomerations, less colloidal stability and poor reliability/repeatability. In addition, these hybrid materials can be provide additional synergistic properties, that is, higher effective surface area, catalytic activity, electrical conductivity, water solubility, and biocompatibility ,. The mechanism for the production of xGnPs decorated with metallic nanoparticles is presented by Lu et al .…”

Metallic nanoislands on graphene: a metamaterial for chemical, mechanical, optical, and biological applications

“…73 Another optical application that has seen considerable attention is the use of metal nanoisland-graphene composites as substrates for surface-enhanced Raman scattering (SERS). 6,74,75,25,76,77,78 The role of graphene in the majority of these applications is as a substrate, allowing easy transfer onto arbitrary substrates for specific applications such as optical strain sensing using SERS (Figure 6c, d). 7 Additionally, it has been shown that graphene can also mitigate the effects of fluorescence in SERS signal-to-noise ratios.…”

Dynamic strain in gold nanoparticle supported graphene induced by focused laser irradiation

“…Graphene on noble-metal nanostructures has been demonstrated to be an attractive nanocomposite with many possible applications 19,20,21 . The surface-enhanced Raman spectroscopy (SERS) on noble-metal NPs is widely used to measure very low amounts of molecules, in some cases even single molecules can be detected 22 .…”