Adsorption of 2-aminobenzothiazole on nano-colloidal silver surface: A concentration and time dependent SERS study aided by density functional theory

Concentration and time dependent SERS spectra of 2-aminobenzothiazole molecule adsorbed on nano-colloidal silver surface have been investigated. The experimental observations are aided by density functional theory. The general interpretation of the concentration dependent SERS spectra corroborates the predominant existence of the N specie of the molecule at 1.0 x 10(-6) M adsorbate concentration which ensures the edge on adsorption of the molecule with its short axis (y-axis) almost normal to the nano-colloidal silver surface. The time dependent SERS spectra of the molecule are characterized by the increase in intensity of bands primarily representing the vibrational signatures emanating from the benzene ring moiety of the molecule. The possible rationale of the selective enhancement of the vibrational signatures emanating from the benzene ring moiety of the molecule with time has been envisaged. (C) 2009 Elsevier B.V. All rights reserved.