A novel poly(γ-benzyl-L-glutamate) (PBLG, 1), which has an anthryl group at the C-terminus of PBLG segment, has been synthesized, and its immobilization onto gold surface based on a specific interhelix interaction and DNA binding property at a self-assembled monolayer surface have been studied. A PBLG carrying a S-S bond at the C-terminus, 3, formed self-assembled monolayers on a gold surface. Within a resulting monolayer of 3, helical rods of the PBLG segment were oriented in the antiparallel manner, allowing an attractive interaction between helix macrodipoles. When a helix-breaking solvent such as DMSO was added to the solution, about a half amount of the adsorbate was released from the monolayer, followed by weakening the interhelix interaction, and a porous monolayer including molecular cavities was formed. Such a cavity size should fit the occupied volume of the helices present in the original assembly. Guest helices of 1 and 2, which has a similar molecular structure to that of I except for the lack of the anthryl moiety, could interact with the host porous monolayer of 1 on gold substrates. The binding properties of DNA onto 1, 2, and 3 mixed monolayers, in which anthryl groups must be located at the monolayer surface, were examined by means of quartz crystal microbalance and X-ray photoelectron spectroscopy. The results indicated that DNA bound to the PBLG mixed monolayers when the anthryl groups at the monolayer surface were in an optimized distribution.
All Science Journal Classification (ASJC) codes
- Organic Chemistry
- Polymers and Plastics
- Inorganic Chemistry
- Materials Chemistry