Quantitative Detection of Singlet Oxygen in PDT by Monitoring Chemiluminescence and Florescence of FCLA

Active oxygen series, especially singlet oxygen (¹O₂), often need to be detected, such as detection of Photodynamic therapy (PDT), seed vigour and plant stress, and so on. Chemiluminescence(CL) is high sensitive to detect active oxygen and can be easily realized with a conventional optical detector. It is utilized in many fields. Fluoresceinyl Cypridina Luciferin Analog (FCLA) is a high sensitive probe of detecting ¹O₂ and superoxide. It is often used to detect or quantify the active oxygen. But as other chemical reaction, quantitative detection active oxygen by CL can´t reach high precision for the reagents concentration change. Using the ¹O₂ produced by photochemical reaction, the characteristic of CL and fluorescence (FL) of FCLA was analyzed. The result shows that the concentration of FCLA will affect the CL and the ratio of concentration can be gotten using the fluorescence. Then the CL can be corrected in real time with the known ratio during PDT.