Adsorption of tyrosine on Ag(110) and Ag(111) surfaces

The adsorption of tyrosine at Ag(110) and Ag(lll) single crystal electrodes has been studied in aqueous solutions of 0.1 M LiClO4. The standard Gibbs energies of adsorption, Delta G(ads)(0), at the potential of maximum adsorption and the interaction parameters, A, using Frumkin's isotherm were calculated. The orientation of the adsorbed tyrosine molecules is different on Ag(lll) and Ag(110) electrodes. At Ag(lll) the molecules adsorb flat with the benzene ring parallel to the electrode, whereas at Ag(110) electrode the orientation is probably vertical with OH group towards the metal. The origin of that difference is probably the different atomic structure of both electrodes.