Microwave-assisted synthesis for a highly selective rhodamine 6G-derived fluorescent sensor and bioimaging.

A new rhodamine 6G derivative has been synthesized by condensation of rhodamine hydrazide and 6-hydroxymethyl-pyridine using microwave-assisted reaction. Naked-eye colorimetric and photo physical studies show the synthesized compound is selectively sensing Cu in CHCN/HO (9:1, v/v) solution. Upon coordination with Cu ion, the spirolactam of is opened, which results in a formation of highly fluorescent complex and change in color of the solution. The Job's plot indicates 1:2 binding stoichiometry between Cu ion and Limit of detection for Cu was determined to be 1.23 μM. The sensor was successfully applied to fluorescent imaging of Cu ion in living cells.