Graphene and its derivatives as surface-enhanced Raman spectroscopy substrates for glucose detection

Diabetes mellitus has become a public health problem over recent years. This medical condition requires a constant monitoring of glucose levels in the blood. Even though glucose produces a weak Raman signal, it is not sufficient for sensitive detection. Surface-enhanced Raman spectroscopy (SERS) is a non-invasive glucose testing method that will improve detection limit and improve point of care services. An ideal substrate for SERS is still a subject of debate. Although metallic nanoparticles made of silver or gold can greatly enhance the intensity of Raman scattering, they have their limitations. Graphene has been proposed as an inert and stable alternative, although it has a lower enhancement factor and is difficult to produce. In recent studies, researchers have combined graphene and its derivatives with metallic nanoparticles to harness the advantages of both materials. Such a combination, along with modifications and different fabrication techniques, can enable glucose detection at very low concentrations (down to 10 -12 -10 –14 M). This review provides an overview of the principle of SERS and covers recently developed graphene-based substrates for SERS analysis of glucose along with their advantages and disadvantages. • Graphene-based SERS for non-invasive glucose sensing with improved sensitivity. • The synergy of graphene, SERS, and glucose sensing for enhanced detection. • Graphene-metal hybrids offer stable, reproducible, and low-noise SERS substrates. • Direct and indirect glucose sensing mechanisms. • Recent advances in graphene-SERS glucose sensors.