Electrode surface modification by a spirobifluorene derivative. An XPS and electrochemical investigation.
Ordered thin layers of a spirobifluorene derivative containing an amino group were formed by grafting them onto a self-assembled monolayer (SAM) of 11-mercaptoundecanoic acid (11-MUA) on gold. Either physical (H-bonding) or chemical bonding (activated by EDCl) was investigated. X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy confirmed that both methods can be used to effectively graft 2-amino-9,9'-spirobifluorene molecules onto the SAM surface, giving high surface coverages, with a significantly higher packing in the case of chemisorbed films. EIS measurements also showed that the covalently bonded spirobifluorene SAMs act as an effective barrier to both ion penetration and heterogeneous electron transfer.
Cecchet
Francesca
F
LISE, Facultés Universitaires Notre-Dame de la Paix, 61 rue de Bruxelles, B-5000 Namur, Belgium.
Fioravanti
Giulia
G
Marcaccio
Massimo
M
Margotti
Massimo
M
Mattiello
Leonardo
L
Paolucci
Francesco
F
Rapino
Stefania
S
Rudolf
Petra
P