A fiber-optic system was developed for exciting and collecting surface-enhanced Raman scattering (SERS) signals generated from a sensing plate tip having silver-coated microparticles deposited on a glass support. Various fiber parameters, such as fiber type, fiber-substrate geometry, and other experimental parameters, were investigated to obtain the optimum conditions for the SERS fiber-optic device. In addition, analytical figures of merit relevant to the performance of the SERS fiber-optic sensor, such as SERS spectral characteristics, reproducibility, linear dynamic range, and limit of detection, were also investigated.
The cucurbit[n]uril (CB[ n]) family of macrocycles are known to bind a variety of small molecules with high affinity. These motifs thus have promise in an ever-growing list of trace detection methods. Surface-enhanced Raman scattering (SERS) detection schemes employing CB[ n] motifs exhibit increased sensitivity due to selective concentration of the analyte at the nanoparticle surface, coupled with the ability of CB[ n] to facilitate the formation of well-defined electromagnetic hot spots. Herein, we report a CB[7] SERS assay for quantification of phenylalanine (Phe) and further demonstrate its utility for detecting peptides with an N-terminal Phe. The CB[7]–guest interaction improves the sensitivity 5–25-fold over direct detection of Phe using citrate-capped silver nanoparticle aggregates, enabling use of a portable Raman system. We further illustrate detection of insulin via binding of CB[7] to the N-terminal Phe residue on its B-chain, suggesting a general strategy for detecting Phe-terminated peptides of clinically relevant biomolecules.
Surface enhanced Raman scattering (SERS) has attracted much research attention for the analysis and trace detection. In this work, we fabricated a gyroid-structured Au-Ag bimetal plasmonic material GSPMMs@Au by incorporating...
Trace Detection of Rhodamine B in Infant Candy by g-C3N4/Ag Nanocomposite as Surface-Enhanced Raman Scattering Substrate