A fluorescent probe for relay recognition of homocysteine and Group IIIA ions including Ga(III).

Challenging relay recognition of Hcy and Ga(3+), has been realized for the first time. Chemodosimeter 1 bearing a 1,1'-binaphthyl skeleton is a fluorescence turn-on probe for Hcy over Cys. The system (2) generated from the recognition of Hcy exhibited further fluorescence enhancement for Ga(3+), which is the first example for specific fluorescent recognition of this metal ion.

A terbium(III)-complex-based on-off fluorescent chemosensor for phosphate anions in aqueous solution and its application in molecular logic gates.

A new Tb(III) complex based on a tripodal carboxylate ligand has been synthesized for the selective fluorescent recognition of phosphate anions, including inorganic phosphates and nucleoside phosphates (e.g., ATP), in Tris buffer solution. The resulting L · Tb complex shows the characteristic emission bands centered at about 495 and 550 nm from the Tb(III)-centered (5)D4 excited state to (7)FJ transitions with J = 6 and 5, where the chelating ligand acts only as an "antenna". Upon the addition of phosphate anions to the aqueous solution of Tb(III) complex, significant "on-off" fluorescence changes were observed, which were attributed to the inhibition of the "antenna" effect between the ligand and Tb(III) after the incorporation of phosphate anions. Furthermore, this unique Tb(III) complex has been successfully utilized to detect phosphate anions with filter papers and hydrogels. Notably, the Tb(III) complex also can be used for the construction of molecular logic gates with TRANSFER and INHIBIT logic functions by using the above fluorescence changes.