Boradiazaindacene-appended calix[4]arene: fluorescence sensing of pH near neutrality.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to E U Akkaya.
Explore the source record for details and available documents.
[reaction: see text] A DNA-binding dye, 4',6-diamidino-2-phenylindole (DAPI) signals AT base pairing with a shift in the fluorescence emission spectrum. The signaling follows W-C base-pairing rules, and both dAMP and dTMP are required for the largest spectral shift. Thus, the dye with its two phosphate receptor sites functions as a molecular NAND gate accepting nucleotides as inputs. Moreover, when the observation wavelength is changed from 470 to 411.5 nm, the gate functions in TRANSFER logic.
We describe the chemical synthesis and fluorescence spectral characterization of a styryl-benzothiazole probe which contains the Ca2+ chelating group BAPTA as an integral part of the chromophoric system. The visible absorption spectrum of this probe displays a dramatic shift in the long wavelength maxima from 508 to 407 nm upon complexation with Ca2+, with a Ca2+ dissociation constant of 1.5 microM. The emission maximum centered at 615 nm is well shifted from the absorption. The emission spectrum displays a small blue shift upon binding Ca2+, allowing this probe to possibly be used as an emission wavelength-ratiometric probe using a single-excitation wavelength. This probe is likely to be the first of a series of long-wavelength ratiometric Ca2+ probes whose structure can be modified for improved quantum yield or altered Ca2+ affinity.