Fluorescent molecular recognition for endocrine-disrupting chemicals and their analogs by fluorescent hetero-modified cyclodextrins

Fluorescent molecular sensing for endocrine-disrupting chemicals and their analogs has been studied by investigating the fluorescence spectral change of regio-selective dansyl-tosyl-modified beta and gamma-cyclodextrins upon the addition of a guest. These host compounds show pure monomer fluorescenc e at around 526 nm; the intensities of the guest-induced fluorescence eithe r increase or decrease according to the accommodation of such guests as dio xin analogs, p-nonylphenol, 2,4-dichlorophenoxyacetic acid, bisphenol A, an d diethylphthalate. The extent of the fluorescence variations with the gues t is employed to display the sensing abilities of these hosts. The sensing parameter, Delta I/I-0, was used to describe the sensing ability of the hos ts, where I and I-0 are the fluorescence intensities in the presence and ab sence of a guest and Delta I=I-I-0. These hosts exhibit highly sensitive an d selective molecular-recognition ability, particularly for 2,4,6-trichloro phenol and bisphenol A.