Silver Metallic Cyclodextrin-Core Star mPEG.

A novel silver metallic beta-cyclodextrin (beta-CD)-core star methoxypolyethylene glycol (mPEG) (SM-CD-SPEG) is presented. For this, a well-defined water-soluble beta-CD-core star mPEG with aldehyde groups (CD-star(ald)PEG, III) is first designed and synthesized via the copper-catalyzed azide-alkyne click reaction. Then, silver nanoparticles are formed within III through the oxidation-reduction reaction between the aldehyde groups and silver ions. The oxidation-reduction reaction is characterized by means of H-1 NMR spectra. And the preparation conditions of SM-CD-SPEG are optimized. The resulting SM-CD-SPEG aqueous solutions exhibit good stability and a unimolecular micelle morphology. Significantly, it is able to obtain solid SM-CD-SPEG samples with molecular water-solubility. This is convenient for storage and further application of SM-CD-SPEG. The SM-CD-SPEG samples also show good catalytic performance toward the reduction reaction of methylene blue (MB) by sodium borohydride (NaBH4).