a complex of 1:1 stoichiometry, the constants (Ka) can
be calculated by non-linear fitting analyses of the titration
curves according to the following Eq. 1 reported before
[21], where CG and CH represent the corresponding concentration
of the guest and host, and A is the intensity of
absorbance at certain concentration of the host and guest.
A0 represents the intensity of absorbance of host only and
Alim is the maximum intensity of absorbance of host when
guest is added. Kass is the affinity constant of host–guest
complexation.