Journal of Physical Chemistry B, Vol.108, No.23, 7646-7650, 2004
pH-triggered assembling system using cooperative binding between cyclodextrin-conjugated poly(epsilon-lysine)s and anionic guest in aqueous media
Various types of cyclodextrin-conjugated poly(epsilon-lysine)s (CDPLs) were prepared as polymeric hosts, and the inclusion properties with 6-(p-toluidino)-2-naphthalenesulfonate (TNS) were investigated at a low concentration under various environmental stimuli. Fluorescence studies revealed that the ability of CDPLs for inclusion complexation was much stronger than that of the corresponding CDs due to their cooperative binding. This property can be controlled by the chemical composition of polymeric hosts such as changing the ring size and varying the degree of substitution of CDs. In addition, the inclusion property of the polymeric host can be modulated by environmental stimuli such as temperature, pH, and ionic strength of aqueous media. Such an interesting functionality results from the combination of the cooperative host-guest interactions and the ionic interaction between the negatively charged TNS moieties and the positive amino groups of poly(epsilon-lysine).