Single DNA Molecules as Probes of Chromatographic Surfaces

摘要

YOYO-I-labeled lambda-DNA was employed as a nanoprobe for different functionalized surfaces to elucidate adsorption in chromatography. While the negatively charged backbone is not adsorbed, the 12-base unpaired ends of this DNA provide exposed purine and pyrimidine groups for adsorption. Self-assembled monolayers (SAMs) formed ongold substrate provide a wide range of choices of surface with well-defined and well-organized functional groups.Patterns of amino-terminated, carboxylic acid-terminated, and hydroxyl-terminated SAMs are generated by lithography. Patterns of metal oxides are generated spontaneously ther deposition of metals. By recording the realtime dynamic motion of DNA molecules at the SAMs/aqueous interface, one can study the various parameters governing the retentivity of an analyte during chromatographic separation. Even subtle differences among adsorptive forces can be revealed.