CVD graphene-based flexible and transparent SERS substrate towards L-tyrosine detection

Abstract

The simple, rapid, reproducible, and sensitive detection of trace amounts of molecules is of great interest in terms of early diagnosis of diseases and food safety in daily-life applications. In this study, low-pressure chemical vapor deposited (LP-CVD) graphene(G)-based flexible and transparent AgNPs/CVDG@AryLite™ nanostructured surface enhanced Raman scattering (SERS) substrate has been demonstrated towards the detection of L-Tyrosine (L-Tyr) amino acid molecules. The synthesize of high-quality, single-crystal monolayer graphene films was achieved with considerably low (62.81 Ω sq.−1) sheet resistance and 94% transmittance at 550 nm wavelength. AgNPs are uniformly formed with a size distribution of about 60 nm on the CVDG surface. The fabricated substrates have been investigated by Rhodamine 6G (R6G) as probe molecule and L-Tyr amino acid molecules with different concentrations to understand the SERS properties. Significant enhancement of R6G and L-Tyr on the fabricated AgNPs/CVDG@AryLite™ SERS substrates obtained even if the 10−8 M R6G and L-Tyr solutions are used. The enhancement factors (EFs) are calculated as 109 and 7.5 × 109 for R6G and L-Tyr, respectively. The results in this research show that the fabricated nanostructured SERS substrates might open up a new path to design flexible and transparent optoelectronic devices towards detection of trace amount of molecules particularly portable spectroscopic instruments.