Département de chimie moléculaire

The formation of stable supramol. interactions between biotin and $\beta$-cyclodextrin was studied. An assocn. const. of 3 × 102 M-1 could be detd. by NMR measurements by mapping the high field shift differences of the $\beta$-cyclodextrin protons (H-3) at different biotin concns. With the aim to demonstrate a new alternative for the immobilization of bioreceptors, biotin and $\beta$-cyclodextrin tagged biomols. were immobilized on transducer surfaces, which were functionalized with the correspondent host-guest partner. The reliability of this new affinity system was investigated using two enzymes (glucose oxidase and polyphenol oxidase) as biomol. models. This supramol. inclusion complex shows clear advantages to the classic biotin-(strept)avidin-biotin system due to a detrimental effect of the addnl. avidin layer reducing the transduction efficiency. A 7-fold increase in the max. c.d. and an almost 20 times higher sensitivity were exhibited by the immobilized biol. layer obtained using this new host-guest system. [on SciFinder(R)]