title: Quantitative surface-enhanced Raman measurements with embedded internal reference.
abstract: Analytical applications of SERS are often more associated with qualitative than quantitative analysis, because of the difficulty in obtaining quantitative SERS results. In this paper we introduce a new strategy to quantitatively measure the SERS signals of analytes based on Au-core/Ag-shell nanoparticles with embedded 4-aminothiophenol as the internal reference. Successful detections of two analytes, Toluidine Blue O in aqueous solution (detection limit of 0.1 μM) and melamine in milk (detection limit of ~5 μM), are demonstrated. The improvement in the linear fitting illustrates that the use of internal reference significantly improves the accuracy of the quantitative SERS measurements. The successful detection of melamine in milk illustrates the versatility of this detection scheme for a wide variety of analytes.
authors.affiliation: Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221, United States.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221, United States.
authors.forename: Rui
authors.initials: R
authors.lastname: Ding
authors.affiliation: Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221, United States.
authors.forename: Padmanabh
authors.initials: P
authors.lastname: Joshi
authors.affiliation: Department of Chemistry, University of Cincinnati, Cincinnati, OH 45221, United States. Electronic address: peng.zhang@uc.edu.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D000818:Animals; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D008892:Milk / Q000737:chemistry*; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014048:Tolonium Chloride / Q000032:analysis; D014227:Triazines / Q000032:analysis*
chemical_list: D000814:Aniline Compounds; D013438:Sulfhydryl Compounds; D014227:Triazines; D014048:Tolonium Chloride; D012834:Silver; D006046:Gold; C064316:4-aminothiophenol; C011907:melamine
keywords: Aminothiophenol; Core–shell nanostructure; Internal reference; Melamine; Quantitative surface-enhanced Raman measurement