Physical chemistry of acridine adsorption onto gold surface: The influence of nanostructure as revealed by near-infrared and tip-enhanced Raman spectroscopy (TERS)

摘要

We report a detailed study of adsorption of acridine and a number of its derivatives: benz[a]acridine, benz[c]acridine, etc. Thermodynamic and kinetic data, obtained by solution-phase near-infrared spectroscopy (NIRS), clearly show a great difference of adsorption behavior for flat and nanorough (app. 4 nm) gold surfaces. Gibbs free energies and adsorption kinetic constants were determined for flat and SERS-type surfaces. The characterization of the polyaromatic monolayer directly at the Au surface, as measured by tip-enhanced Raman spectroscopy in scanning tunneling microscope mode (STM-TERS), has confirmed the dependence of the adsorption parameters on the (nano)roughness of the metal surface.