Acetate selective fluorescent turn-on sensors derived using vitamin B6 cofactor pyridoxal-5-phosphate.

Two new Schiff base receptors have been synthesized by condensation of pyridoxal-5-phosphate with 2-aminophenol (L(1)) or aniline (L(2)). In DMSO, the receptors showed both chromogenic and 'turn-on' fluorescence responses selectively in the presence of AcO(-) and F(-). However, in mixed DMSO-H2O medium, the receptors showed AcO(-) selective 'turn-on' fluorescence without any interference from other tested anions including F(-). The detection limit for AcO(-) was found to be 7.37 µM and 22.9 µM using the receptors L(1) and L(2), respectively.

An aqueous friendly chemosensor derived from vitamin B6 cofactor for colorimetric sensing of Cu²âº and fluorescent turn-off sensing of Fe³âº.

Chemosensor L derived from vitamin B6 cofactor pyridoxal-5-phosphate was investigated for the selective detection of Cu(2+) and Fe(3+) in aqueous medium. Sensor L formed a 1:1 complex with Cu(2+) and displays a perceptible color change from colorless to yellow brown with the appearance of a new charge transfer band at ~450 nm. In contrast, the fluorescence of L was quenched selectively in the presence of Fe(3+) without any interference from other metal ions including Cu(2+).