ABSTRACT
A single crystal X-ray structurally characterized BODIPY based probe, THBPY, derived from 4-hydroxy-5-isopropyl-2 methyl-isophthalaldehyde, detects nano-molar lysine in aqueous medium. In the presence of lysine, THBPY visibly changes its color and fluorescence profile due to the formation of a stable imine bond. A distinctive color change allows for facile discrimination over other amino acids in a wide range of concentrations of lysine. The detection limit for lysine is 0.001 µM by a fluorescence method and 0.01 µM by a colorimetric method. The probe shows good reversibility for multiple uses and cleanly discriminates between lysine and other amino acids. Density functional theoretical studies closely resemble experimental results.
Subject(s)
Boron Compounds/chemistry , Coloring Agents/chemistry , Lysine/analysis , Phthalic Acids/chemistry , Cell Line, Tumor , Colorimetry , Crystallography, X-Ray , Fluorescence , Fluorescent Dyes/chemistry , Humans , Models, Molecular , Optical ImagingABSTRACT
A rhodamine-cyanobenzene conjugate, (E)-4-((2-(3',6'-bis(diethylamino)-3-oxospiro[isoindoline-1,9'-xanthene]-2-yl)ethylimino)methyl)benzonitrile (1), which structure has been elucidated by single crystal X-ray diffraction, was synthesized for selective fluorescent "turn-on" and colorimetric recognition of hydrazine at physiological pH 7.4. It was established that 1 detects hydrazine up to 58 nM. The probe is useful for the detection of intracellular hydrazine in the human breast cancer cells MCF-7 using a fluorescence microscope. Spirolactam ring opening of 1, followed by its hydrolysis, was established as a probable mechanism for the selective sensing of hydrazine.
