Direct observation of a cooperative mechanism in the adsorption of heavy metal ions to thiolated surface by in-situ surface plasmon resonance measurements

S-type adsorption kinetics, obtained by surface plasmon resonance spectroscopy measurements, suggest that the rate of Pt^2+ adsorption on 1,6-hexanedithiol (HDT) on gold increases until the surface coverage reaches ca. 17%, after which, the adsorption profile of Pt^2+ follows Langmuirian behavior for the surface coverage.