title: Development of a long-range surface-enhanced Raman spectroscopy ruler.
abstract: Optical-ruler-based distance measurements are essential for tracking biomolecular processes in a wide range of analytical biochemical applications. The normally used Förster resonance energy transfer (FRET) ruler is not useful for investigating distance-dependent properties when distances are more than 10 nm. Driven by this limitation, we have developed a long-range surface-enhanced Raman spectroscopy (SERS) optical ruler using oval-shaped gold nanoparticles and Rh6G dye-modified rigid, variable-length double-strand DNAs. The bifunctional rigid dsDNA molecule serves as the SERS-active ruler. Our experimental results show that one can tune the length of the SERS ruler between 8 and ∼18 nm by choosing the size of the oval-shaped gold nanoparticles. A possible mechanism for our observed distance-dependent SERS phenomenon is discussed using the Gersten and Nitzan model. Ultimately, our long-range SERS molecular rulers can be an important step toward understanding distance-dependent biological processes.
authors.affiliation: Department of Chemistry, Jackson State University, Mississippi 39217-0510, United States.
authors.forename: Anant Kumar
authors.initials: AK
authors.lastname: Singh
authors.forename: Sadia Afrin
authors.initials: SA
authors.lastname: Khan
authors.forename: Zhen
authors.initials: Z
authors.lastname: Fan
authors.forename: Teresa
authors.initials: T
authors.lastname: Demeritte
authors.forename: Dulal
authors.initials: D
authors.lastname: Senapati
authors.forename: Rajashekhar
authors.initials: R
authors.lastname: Kanchanapally
authors.forename: Paresh Chandra
authors.initials: PC
authors.lastname: Ray
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D008969:Molecular Sequence Data; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D012238:Rhodium / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D005456:Fluorescent Dyes; D006046:Gold; D004247:DNA; D012238:Rhodium