The light absorption properties of the samples were analyzed using a UV-Vis spectrophotometer. The spectrophotometer used in this study was spectronic GENESYS 10 Bio (Thermo Scientific, USA). Approximately 1 mL of each sample was prepared and placed in a single-cell cuvette with a specific path length. The cuvette was then inserted into the spectrophotometer, and the absorbance spectrum was recorded over the desired wavelengths (365 and 405 nm). To ensure accurate measurements, Milli-Q water was used as a reference.