RESEARCH ARTICLE Photophysical and photodynamic properties of Pyronin Y in micellar media at different temperatures Burcu Meryem Beşer 1 | Mustafa Arik 2 | Yavuz Onganer 2 1 Department of Chemistry, Erzincan Binali Yıldırım University, Erzincan, Turkey 2 Department of Chemistry, Atatürk University, Erzurum, Turkey Correspondence Mustafa Arik, Department of Chemistry, Atatürk University, Erzurum, 25100, Turkey. Email: marik@atauni.edu.tr Abstract In this study, photophysics and photodynamical properties of Pyronin Y (PyY) in dif- ferent liquid media were investigated. Interactions of PyY, which is a positively charged pigment compound pertaining to the xanthene derivatives with surfactants possessing distinct charges, were determined by using the molecular absorption and fluorescence spectroscopy techniques. It was observed that band intensities of absorption and fluorescence spectra belonging to PyY increase in proportion to the water when compared to three micelle systems, cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and Triton X‐100 (TX‐100). This suggests that interactions in micelle systems are different from those in deionized water, and solva- tion and surface interactions modify. It is determined that the strongest interaction occurs between PyY dye and SDS, anionic surfactant, and this interaction arises from the electrostatic forces. Calculated photophysical parameters indicated that the microenvironment of PyY in SDS micelle is different to that of other systems. In tem- perature studies, it was reported that increasing the temperature of the samples increased non‐radiative transitions. Steady‐state fluorescence anisotropy values were calculated by using fluorescence intensities of PyY compound in pre‐micellar, micellar and post‐micellar systems. Once the PyY fluorescence probe is added to the surfac- tant containing solutions below the critical micelle concentrations, the measured anisotropy values were found to be low because the probe remains in the deionized water phase. When the surfactant concentration of the medium becomes closer to the critical micelle concentrations, the steady‐state anisotropy value prominently increases. This is because of the restrictions on the rotational diffusion of the probe in micellar solution. It is observed that positively charged PyY shows a higher affinity to the negatively charged SDS compared with the positively charged CTAB and neutral TX‐100 surfactants. This can be explained by Coulombic interactions. KEYWORDS dye–surfactant interactions, photodynamics, photophysics, Pyronin Y 1 | INTRODUCTION Fluorescent dyes are used as probes for the investigation of physico- chemical, biochemical and biological systems. [1–3] These probes supply remarkable data on polymer chain mobility, microviscosity, lipid– protein interactions, DNA and RNA helix structure, structural changes and conformational transitions in biological membranes of the envi- ronment. [4–6] Pyronin Y (PyY) is a xanthene derivative compound with Received: 29 November 2018 Revised: 3 February 2019 Accepted: 6 February 2019 DOI: 10.1002/bio.3624 Luminescence. 2019;1–11. © 2019 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/bio 1