Preparation of surface-block dendrimer by using air-water interface and its self-assembling property on gold

We describe the preparation and characterization of surface-block dendrimer, which consists of photoinitiatable xanthate groups and gold-adsorbable mercapto groups. A xanthate-modified poly(amido amine) dendrimer(generation 4, ethylenediamine core) (G 4-X) was newly prepared. G 4-X was found to form a monolayer at the air-water interface from pi -A isotherm and reflection-absorption spectroscopy. Xanthate groups of this monolayer attached to the water surface were then partially hydrolyzed with addition of the aqueous KOH to the subphase. As a result, surface-block dendrimer containing xanthate groups and mercapto groups(G 4-X-SH) was easily obtained. Quartz Crystal Microbalance measurement showed that G 4-X-SH could be immobilized onto gold substrate by using Langmuir-Blodgett method and Self-assembling method. In addition, surface property of G 4-X-SH monolayer was examined from AFM measurements.