A Reusable SERS Substrate with Internal Standard for the Detection of N-Butylamine Gas

Surface-enhanced Raman scattering (SERS) has become an effective and sensitive analysis tool for the detection of various molecules. Nevertheless, it is a challenge to fabricate reusable SERS substrates for detecting gaseous molecules. Here, a self-calibrated and reusable SERS substrate has been developed for the quantitative analysis of n-butylamine. The obtained substrate enhances gas enrichment capability through the coordination interaction of Fe2O3 with the porous structure of ZIF-8, and strengthens the Raman signal intensity by the localized surface plasmon resonance of Ag nanoparticles. Ethanethiol is employed as an internal standard to enhance analysis accuracy. The substrate exhibits excellent quantitative analysis (linear correlation coefficient, R2 = 0.996), signal uniformity (RSD = 6.3%), and batch reproducibility (RSD = 4.8%). Moreover, the substrate achieves self-cleaning through photocatalysis. After five cycles, the substrate retains high SERS activity (RSD = 3.13%), exhibiting excellent reusability.