Adsorption-desorption properties of porphyrins on metal nanosurfaces

Author: Mgr. Petra Šimáková
Supervisor: Prof. RNDr. Marek Procházka, Dr.
Type: Bachelor

Abstract: The subject of this work is a study of adsorption-desorption properties of cationic 5,10,15,20-tetrakis(1-methyl-4-pyridyl)porphyrin (TMPyP) and anionic 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TSPP) on SERS-active surfaces prepared by immobilization of gold colloidal nanoparticles to silanized glass plates. Time dependence of porphyrin adsorption was measured for porphyrin concentrations in the order of 10-6 M by using UV-VIS absorption spectroscopy. Adsorption of TMPyP was well detectable; saturation was achieved during 8-25 minutes, it corresponds to the measurements of the time dependences of SERRS intensity on adsorption time. Adsorbed amount of TMPyP in saturation was estimated as 1-2×1014 molekul/cm2 and it was not concentration dependent in the used concentration range. In the case of TSPP, the adsorption is weak and almost undetectable in our experiment.

Keywords: SERS, adsorption, gold nanoparticles, porphyrin