Influencing the Binding Selectivity of Self-Assembled Cyclodextrin Monolayers on Gold through Their Architecture
✍ Scribed by Menno R. de Jong; Jurriaan Huskens; David N. Reinhoudt
- Publisher
- John Wiley and Sons
- Year
- 2001
- Tongue
- English
- Weight
- 171 KB
- Volume
- 7
- Category
- Article
- ISSN
- 0947-6539
No coin nor oath required. For personal study only.
✦ Synopsis
Cyclodextrin derivatives modified with seven thioether moieties (1) or with one thiol moiety (2) bind to gold. Monolayers on gold of 1 or mixed monolayers of 2 and mercaptoundecanol were characterized by electrochemistry, wettability, and atomic force microscopy (AFM). Monolayers of 1 are well-ordered, but the order in the mixed monolayers depends on the ratio of 2 to mercaptoundecanol. With sufficient al-kyl chains to fill the space under the cyclodextrin moiety of 2, the monolayers are densely packed. Guest recognition at these monolayers in water was studied by surface plasmon resonance (SPR) spectroscopy. For simple organic guests, monolayers of 1 showed the same selectivity and binding strength as b-cyclodextrin in solution; however, the selectivity towards steroidal bile salts differs from solution. The mixed monolayers of 2, in which the cyclodextrin is less substituted and has more flexibility, bind steroidal guests (6 a ± 6 e) with the same selectivity as b-cyclodextrin in solution.