In this report the photophysical property of newly synthesized fluorescein based derivative 2-(5-((2,4-dichlorophenyl)diazenyl)-6-hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acid by spectroscopic and density functional theory technique. The structural of the synthesized molecule was studied by nuclear magnetic resonance and fourier transform infrared spectroscopy technique, from this analysis it has been revealed that the molecule has a stable structure and about the functional groups present in the sample. From the UV-Visible spectroscopy measurement has revealed the solute-solvent interaction behaviour of the molecule and it has been observed that the bathochromic shift was of about 5 nm, from the fluorescence measurement it has revealed that the emission has been observed at green region and from the power spectra it has been confirmed the same. The DFT study has been derived for the synthesized molecule the optimized structure, electrostatic potential maps, theoretical energy band gap and HOMO and LUMO visualizations are derived from the Gaussian 09W software and it has been found that the bandgap energy is found to be 2.060eV for benzene solvent and 3.08 eV in methanol solvent, the electrophilic and nucleophilic sites exhibited at the substitution group of the molecule. The outcomes of the study clearly endorse the synthesized fluorescein derivative suitable for photonic/optoelectronic applications.