Reactive oxygen species (ROS) are known to exert both beneficial and harmful effects in the human body. Singlet oxygen (1O2), is highly reactive and considered as one of the ROS, although it is not a radical molecule. 1O2 reacts with many kinds of biological components such as lipids, proteins, and nucleic acids. 1O2 is short lived because it reacts with biomolecules and collisions with water molecules rapidly causing the return of 1O2 to the ground state, and is therefore not easy to quantify. Antioxidants, such as β-carotene, lycopene and astaxanthin, are quenchers of 1O2. To compare the 1O2 quenching activity of new test compounds with these typical quenchers, it is desirable to measure 1O2 specifically, speedily, and easily. In this paper, various methods for the measurement of 1O2, such as UV-Vis spectroscopy, fluorescence spectroscopy, and electron spin resonance, were compared for the purpose of evaluating the 1O2 quenching activity of various test compounds.

Singlet oxygen (1O2), 1O2 detection probe, Quenching activity, UV-Vis spectroscopy, Fluorescence spectroscopy, Near-infrared spectroscopy, Electron spin resonance