HPF solution is widely used in biological research as a fluorescent probe for detecting reactive oxygen species (ROS), particularly hydroxyl radicals. Its application is crucial in studying oxidative stress in cells, as it selectively reacts with hydroxyl radicals to produce a highly fluorescent compound, enabling real-time monitoring of ROS levels. This makes it valuable in fields like cancer research, neurodegenerative disease studies, and toxicology, where understanding oxidative damage is essential. Additionally, HPF is utilized in environmental science to assess the presence of ROS in water systems, helping to evaluate pollution and its impact on ecosystems. Its specificity and sensitivity make it a preferred tool for both in vitro and in vivo applications.