title: Isotope edited internal standard method for quantitative surface-enhanced Raman spectroscopy.
abstract: A new isotope edited internal standard (IEIS) method for quantitative surface-enhanced Raman spectroscopy (SERS) is demonstrated using rhodamine 6G (R6G-d0) and rhodamine 6G (R6G-d4) edited with deuterium. The reproducibility and accuracy of the IEIS method is investigated both under optical resonance (SERRS) and nonresonance (SERS) conditions. A batch-to-batch concentration measurement reproducibility of better than 3% is demonstrated over a concentration range of 200 pM-2 microM with up to a factor of 3 difference between the concentration of the analyte and its IEIS. The superior performance of the IEIS method is further illustrated by comparing results obtained using absolute SERS/SERRS intensity calibration (with no internal standard) or using adenine (rather than R6G-d4) as an internal standard for R6G concentration quantization. Potential biomedical gene expression and comparative proteomic applications of the IEIS method are discussed.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, USA. zhang17@purdue.edu
authors.forename: Dongmao
authors.initials: D
authors.lastname: Zhang
authors.forename: Yong
authors.initials: Y
authors.lastname: Xie
authors.forename: Shirshendu K
authors.initials: SK
authors.lastname: Deb
authors.forename: V Jo
authors.initials: VJ
authors.lastname: Davison
authors.forename: Dor
authors.initials: D
authors.lastname: Ben-Amotz
mesh_terms: D000225:Adenine / Q000032:analysis; D003903:Deuterium / Q000737:chemistry*; D015394:Molecular Structure; D055095:Optics and Photonics; D012015:Reference Standards; D015203:Reproducibility of Results; D012235:Rhodamines / Q000032:analysis*; D012680:Sensitivity and Specificity; D013059:Spectrum Analysis, Raman / Q000379:methods* / Q000592:standards
chemical_list: D012235:Rhodamines; C026188:rhodamine 6G; D003903:Deuterium; D000225:Adenine