环糊精修饰金纳米粒子对含色氨酸寡肽的键合行为

hree b-cyclodextrin derivatives were respectively chemisorbed onto the gold nanoparticles to give the b-cyclodextrin-coated gold nanoparticles, which were sufficiently characterized by 1H NMR, FT-IR, elemental analyses, ICP-AES and transmission electron microscopy (TEM). Spectrophotometric studies showed that these coated gold nanoparticles could efficiently enhance the fluorescence of tryptophan and tryptophan-containing oligopeptides through the selective binding of b-cyclodextrin cavities with the tryptophan groups attached on the surface of gold nuclei. Fluorescence titrations give the apparent association constants for the binding of coated gold nanoparticles with tryptophan and tryptophan-containing oligopeptides. The molecular binding ability and selectivity are discussed from the viewpoint of induced-fit effect between host and guest.