title: Density functional theoretical modeling, electrostatic surface potential and surface enhanced Raman spectroscopic studies on biosynthesized silver nanoparticles: observation of 400 PM sensitivity to explosives.
abstract: Interaction of adsorbate on charged surfaces, orientation of the analyte on the surface, and surface enhancement aspects have been studied. These aspects have been explored in details to explain the surface-enhanced Raman spectroscopic (SERS) spectra of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW or CL-20), a well-known explosive, and 2,4,6-trinitrotoluene (TNT) using one-pot synthesis of silver nanoparticles via biosynthetic route using natural precursor extracts of clove and pepper. The biosynthesized silver nanoparticles (bio Ag Nps) have been characterized using UV-vis spectroscopy, scanning electron microscopy and atomic force microscopy. SERS studies conducted using bio Ag Nps on different water insoluble analytes, such as CL-20 and TNT, lead to SERS signals at concentration levels of 400 pM. The experimental findings have been corroborated with density functional computational results, electrostatic surface potential calculations, Fukui functions and ζ potential measurements.
authors.affiliation: Department of Inorganic & Physical Chemistry Indian Institute of Science , Bangalore 560012, India.
authors.forename: Sanchita
authors.initials: S
authors.lastname: Sil
authors.forename: Deepika
authors.initials: D
authors.lastname: Chaturvedi
authors.forename: Keerthi B
authors.initials: KB
authors.lastname: Krishnappa
authors.forename: Srividya
authors.initials: S
authors.lastname: Kumar
authors.forename: S N
authors.initials: SN
authors.lastname: Asthana
authors.forename: Siva
authors.initials: S
authors.lastname: Umapathy
mesh_terms: D001372:Aza Compounds / Q000737:chemistry*; D053834:Explosive Agents / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008962:Models, Theoretical; D012834:Silver / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D055672:Static Electricity; D013499:Surface Properties
chemical_list: C482139:2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaaza-isowurtzitane; D001372:Aza Compounds; D053834:Explosive Agents; D006571:Heterocyclic Compounds; D012834:Silver