Fluorescence analysis of natural dyes from Plumeria rubra (red and white) flowers

Eco-friendly aqueous dye is extracted from the flowers of Plumeria rubra (red and white). Absorption, luminescence and fluorescence spectroscopic properties of the extracted dyes are analyzed by respective spectroscopic techniques. Fluorescence quantum yields, Stoke's shift, fluorescence life time, radiative and non-radiative rate constants are discussed with various excitation wavelengths in the range of 200-420 nm. Hence, a suitable excitation wavelength of the extracted dye is found to be in the range of 300-370 nm and the dye shows strong fluorescence in this range. Radiative and non-radiative rate constants and fluorescence life time results elucidate the effective fluorescence properties of the extracted dyes. It can be used as a potentially durable natural dye for fluorescence related applications. (C) 2018 Elsevier GmbH. All rights reserved.