Fluorescence Anisotropy Studies on Bodipy (Pyrromethene 546) Dye as a Novel Thermal Probe.

Abstract

In the present work, fluorescence anisotropy studies of BODIPY (pyrromethene 546 or C14H17BF2N2) dye have been performed and found that it has a potential to be used as a thermal probe to measure the temperature of microfluid. It is well-known that a dye rotates in its excited state, so to control the molecular rotation of the dye in the excited state, sorbitol is used in the solution. It has been found that adding sorbitol, fluorescence anisotropy increases, fluorescence lifetime decreases. It has been found that adding sorbitol, temperature sensitivity increases. To study the effect of -CH2 groups on fluorescence properties, another BODIPY (pyrromethene 597 or C22H33BF2N2) dye is also used, as C14H17BF2N2 and C22H33BF2N2 have similar structures with a difference of only -8CH2 groups. It has been found that C22H33BF2N2 has superior properties over C14H17BF2N2, i.e., pyrromethene 597 shows larger temperature sensitivity as compared to pyrromethene 546, even without the addition of sorbitol.