Time-Resolved In-Situ SERS Monitoring of Toluene Vapor Adsorption on Silver Nanorod Substrates

Gas-surface adsorption is inherently time dependent, yet many spectroscopic measurements capture only steady-state signals after exposure. In-situ surface-enhanced Raman spectroscopy (SERS) offers a direct approach for monitoring adsorption processes at plasmonic interfaces, where Raman signals are highly sensitive to molecular proximity and surface interactions. Here, we present a reproducible protocol for time-resolved in-situ SERS measurements using silver nanorod (AgNR) substrates fabricated by oblique angle deposition (OAD), integrated with a Raman spectrometer and a controlled vapor-delivery system. Using toluene vapor as a model analyte, nitrogen carrier gas is passed through a bubbler and directed across the AgNR substrate inside a gas cell while Raman spectra are collected sequentially at fixed time intervals. This configuration enables observation of spectral evolution during exposure, including gradual signal growth and delayed emergence of characteristic vibrational bands. The workflow includes AgNR substrate preparation by OAD, substrate validation using probe-molecule SERS measurements, operation of the in-situ gas-delivery system, sequential Raman acquisition, and post-measurement spectral processing using SpectraGuru. Emphasis is placed on maintaining stable experimental conditions and distinguishing persistent time-dependent spectral trends from transient features caused by instrumental artifacts or environmental fluctuations. This protocol provides a practical framework for studying dynamic gas-surface interactions on plasmonic substrates and for evaluating SERS-based platforms for time-resolved adsorption studies.