Gold is an exotic material with d-electrons deciding electronic mappings andconfigurations of adsorbed molecules. The specific interaction of Au atoms and S-, Ncappedmolecules make gold nanoparticles widely applied in the medicine transport andimmunoassay. Density functional theory demonstrates that the electronic structure ofAu adatoms is d9s1but not d10s0 in the forms of Au-thiolates. The surrounding Ausurface atoms are passivated leading to both Au-Au and S-S interactions. A wide range of surface phenomena of nanoparticle size-control and break-junctions in surface physics and chemistry including electrochemistry and electrochemical scanning tunneling microscopy (in situ STM) are explained with this theory. Iron porphyrin is a well-known active redox center of cytochrome c and hemoglobin/myoglobin assisting membrane-crossing electron transfer or blood oxygentransport. The electronic states and configurations of iron porphyrin affect the electrochemical properties of the metalloproteins, where the artificial constructed proteins are designed by the mutations of amino residues or the structural optimizations of iron porphyrins. Iron porphyrin adsorption on graphite and graphene surfaces by п-п electron stacking has been widely studied and the catalytic activity found to be enhanced warranting the notion of enzyme mimics. Weak physisorption was, however, recently observed by in situ STM, but the electronic properties of iron porphyrin adsorbed on gold has not been addressed before. This issue is, however, critical. We report here a study of ironporphyrin on the three low-index Au-surfaces using a combination of electrochemistry and density functional theory.
|Publication status||Published - 2017|
|Event||Forth EuCheMS Inorganic Chemistry Conference (EICC-4) - University of Copenhagen, Southern Campus (KUA), Copenhagen, Denmark|
Duration: 2 Jul 2017 → 5 Jul 2017
|Conference||Forth EuCheMS Inorganic Chemistry Conference (EICC-4)|
|Location||University of Copenhagen, Southern Campus (KUA)|
|Period||02/07/2017 → 05/07/2017|