title: Quantitative Comparison of Raman Activities, SERS Activities, and SERS Enhancement Factors of Organothiols: Implication to Chemical Enhancement.
abstract: Studying the correlation between the molecular structures of SERS-active analytes and their SERS enhancement factors is important to our fundamental understanding of SERS chemical enhancement. Using a common internal reference method, we quantitatively compared the Raman activities, SERS activities, and SERS enhancement factors for a series of organothiols that differ significantly in their structural characteristics and reported chemical enhancements. We find that while the tested molecules vary tremendously in their normal Raman and SERS activities (by more than 4 orders of magnitude), their SERS enhancement factors are very similar (the largest difference is less than 1 order of magnitude). This result strongly suggests that SERS chemical enhancement factors are not as diverse as initially believed. In addition to shedding critical insight on the SERS phenomena, the common internal reference method developed in this work provides a simple and reliable way for systematic investigation of the correlation between molecular structures and their normal Raman and SERS activities.
authors.affiliation: Department of Chemistry, Mississippi State University , Mississippi State, Mississippi 39762, United States.
authors.forename: Siyam M
authors.initials: SM
authors.lastname: Ansar
authors.affiliation: Department of Sciences and Mathematics, Mississippi University for Women , Columbus, Mississippi 39701, United States.
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Chemistry, University of Central Florida , Orlando, Florida 32816, United States.
authors.forename: Shengli
authors.initials: S
authors.lastname: Zou
authors.affiliation: Department of Chemistry, Mississippi State University , Mississippi State, Mississippi 39762, United States.
authors.forename: Dongmao
authors.initials: D
authors.lastname: Zhang
keywords: Raman; SERS; enhancement factor; gold nanoparticle; silver nanoparticle