Related Experiment Video
Updated: May 31, 2025

Time-resolved Photophysical Characterization of Triplet-harvesting Organic Compounds at an Oxygen-free Environment Using an iCCD Camera
Published on: December 27, 2018
Luminescence Properties of Hoechst 33258 in Polyvinyl Alcohol Films
Bong Lee1, Agnieszka Jablonska1, Danh Pham1
1Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX 76129, USA.
Abstract:
We report a comprehensive investigation of the photophysical properties of Hoechst 33258 (HOE) embedded in polyvinyl alcohol (PVA) films. HOE displays a bright, highly polarized, blue fluorescence emission centered at 430 nm, indicating effective immobilization within the polymer matrix of PVA. Its fluorescence quantum yield is notably high (~0.74), as determined relative to a quinine sulfate standard. In addition, we observed that HOE-doped PVA films exhibit room temperature phosphorescence (RTP) that remains visible for several seconds after UV excitation ceases. The slightly negative phosphorescence anisotropy implies that the triplet-singlet radiative transition is orthogonal to the singlet-singlet transition governing fluorescence. Notably, we observed that direct triplet-state excitation at longer wavelengths (beyond the primary absorption band) produces highly polarized RTP. We believe this possibility of direct triplet-state excitation opens new avenues for studying RTP in polymer-immobilized molecules.
Related Concept Videos
Labeling DNA Probes
Radioisotopes, fluorophores, or small molecule binding partners like biotin or digoxigenin, are the most widely used reporter tags for labeling DNA probes. These labels can be attached to the probe DNA molecule via...
Photoluminescence: Applications
Photoluminescence: Fluorescence and Phosphorescence
A pair of electrons in a...
Variables Affecting Phosphorescence and Fluorescence

