title: Adsorption and sub-nanomolar sensing of thioflavin T on colloidal gold nanoparticles, silver nanoparticles and silver-coated films studied using surface-enhanced Raman scattering.
abstract: Raman and surface-enhanced Raman scattering (SERS) studies of thioflavin T (ThT) in solid, solution, gold nanoparticles (GNPs), silver nanoparticles (SNPs) and silver-coated films (SCFs) were investigated. Concentration-dependent SERS spectrum of ThT in GNPs and SNPs indicated the existence of two possible structures, one with the torsional angle (φ) between benzothiazole and dimethylaminobenzene rings being 37° and the other with φ=90°. The SERS spectrum of ThT in SCFs were similar to the Raman spectrum of solid and solution that suggests φ=37°. In this paper, the high sensitivity of the SERS technique was employed for sub-nanomolar (picomolar) sensing of ThT.
authors.affiliation: Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. Electronic address: nanbis@gmail.com.
authors.forename: Nandita
authors.initials: N
authors.lastname: Maiti
authors.affiliation: Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
authors.forename: Ridhima
authors.initials: R
authors.lastname: Chadha
authors.affiliation: Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Das
authors.affiliation: Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
authors.forename: Sudhir
authors.initials: S
authors.lastname: Kapoor
mesh_terms: D000327:Adsorption; D052160:Benzothiazoles; D004583:Electrons; D017979:Gold Colloid / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000648:ultrastructure; D008968:Molecular Conformation; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013844:Thiazoles / Q000032:analysis* / Q000737:chemistry
chemical_list: D052160:Benzothiazoles; D017979:Gold Colloid; D013844:Thiazoles; C009462:thioflavin T; D012834:Silver
keywords: Gold nanoparticles; Silver nanoparticles; Silver-coated films; Sub-nanomolar sensing; Surface-enhanced Raman scattering; Thioflavin T