▎ 摘　　要

NOVELTY - The SERS substrate (100) has a substrate (110). The substrate is selected from a paper or a paper type (plastic films) substrate. A mono/multi-layer of graphene (120) is provided. A monolayer of 3-Mercaptopropyl trimethoxysilane (MPTMS) (130) is provided. A nanoparticle layer (140) of a colloidal solution is provided with metal nanoparticles. A thiol layer (150) is provided in which the mono/multi-layer of the graphene is present as a first layer on the substate. The monolayer of the MPTMS is spin coated on the mono/multi-layer of graphene and the colloidal solution containing metal nanoparticles is spin coated as the nanoparticle layer on top of the monolayer of MPTMS. The thiol layer is spin coated on the top of the nanoparticle layer. USE - SERS substrate for detection of an analyte such as explosives, narcotics, or other agents including substances with passengers/their belongings at airports or other security checkpoints in low/very-low concentration. ADVANTAGE - The thiols help in passivation and increase wettability, thus increasing the adsorption of the analyte on the surface of surface enhanced Raman spectroscopy (SERS) substrate and subsequently enhance the amplification factor. They also increase the stability of the SERS substrate. The method provides ultra-high sensitivity, high speed, low cost, portability, and reproducibility of such detection instruments. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: a process for preparation of a SERS substrate; and a method for detection of an analyte. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic arrangement of the layers or monolayers or nanolayers present on SERS substrate for detection of an analyte. 100SERS substrate 110Substrate 120Mono/multi-layer of grapheme 130MPTMS 140Nanoparticle layer 150Thiol layer