Interactions between chalcone-modified beta-cyclodextrin and transitional metal ions

A nerv cyclodextrin derivative (DMAC - CD) was prepared by linking a chalco ne moiety to the 6 C position of beta - cyclodextrin with an aza - oxa - al kyl chain. The interaction between DMAC - CD and transitional metal ions we re studied by steady state and time - resolved fluorescence spectroscopy. T he experimental results showed that the complexes of DMAC - CD with metal i ons were formed in the aqueous solution due to its self - inclusion conform ation, which was in favor of binding metal ions. For this reason, the quenc hing curve of different metal ions for DMAC - CD all deviated from the Ster n - Volmer linear relationship owing to the steady state quenching mechanis m. The stability constants and fluorescence quenching rate constants were b oth determined, indicating this chalcone - modified cyclodextrin has a high er sensitivity and selectivity for transitional metal ions, especially for Cu2+.