Phenazopyridine hydrochloride (PHP), an azo dye, has been used in pharmaceutical chemistry. This study delineated the synthetic pathway of enzymatically oligomerized based on PHP. The molecular characterization of O-PHP was determined via UV-vis, infrared, H-1 NMR and C-13 NMR techniques. Solvent effect on the electronic absorption of O-PHP was investigated. Further analysis was fulfilled by photoluminescence (PL), thermal analysis (TG-DTA and DSC) and electrochemical (CV) measurements. PL measurements resulted in the response of O-PHP with bicolor light emissions upon Ultra-Violet and visible light, respectively. CV method was utilized to evaluate the HOMO-LUMO energy levels and the electrochemical (E-g') band gaps of the monomer and the oligomer. Optical and electrochemical band gaps of O-PHP were lower than those of PHP, confirming the accomplished synthesis of pi-conjugated structure of O-PHP. Scanning Electron Microscopy (SEM) technique was carried out to study the surface morphology of O-PHP. Additionally, the results of thermal studies of TG-DTA and DSC techniques showed that O-PHP was thermally stable compound. (C) 2019 Elsevier B.V. All rights reserved.