Spectral properties of quinine sulfate in PVA films for front-face format emission measurements

Abstract The luminescence properties of quinine sulfate (QS) embedded in poly(vinyl alcohol) (PVA) film have been studied in detail. Fluorescence excitation and emission spectra were measured using a front-face configuration, and the corresponding intensities were tabulated. A fluorescence quantum yield of 0.51 was determined for QS-doped PVA, using QS dissolved in 1N H 2 SO 4 . Both excitation and emission anisotropy measurements indicated effective immobilization of QS molecules within the polymer matrix. The fluorescence lifetime of QS-doped PVA was measured using a picosecond-pulsed 375 nm laser diode and analyzed with both exponential and Lorentzian distribution models. The broad lifetime distribution suggests a complex interaction between QS molecules and the polymer matrix. The QS-doped PVA films are well suited for measurements involving solid materials and front-face geometries.