Hydrogen-Bond-Mediated Biomolecular Trapping: Reversible Catch-and-Release Process of Common Biomolecules on a Glycine-Functionalized Si(111)7×7 Surface

Adsorption and desorption of several small prototypical biomolecules: glycine, glycylglycine, alanine, adenine, and thymine on a glycine-functionalized Si(111)7� 7 surface have been investigated by X-ray photoelectron spectroscopy. Glycine has been found to adsorb on Si(111)7� 7t hrough N-H dissociation, which makes the unreacted carboxyl group of the interfacial glycine adlayer an effective means to capture these biomolecules (except for thymine) through (O-H 333 N) hydrogen bonding. Furthermore, the captured molecules can be released simply by annealing to 120 C for 10 s. This hydrogen-bond-mediated catch-and-release mecha- nismissupportedbytheappearanceanddisappearanceofthecharacteristichydrogen- bond N 1s features at 401.4 eVand is found to be reversible. The glycine-functionalized Si(111) surface therefore provides a flexible platform for potential applications as selective molecular traps, chemical sensors, and biomolecular electronic components. SECTION Surfaces, Interfaces, Catalysis