Study And Application Of Optical Fiber Detection Technology For Photosensitized Singlet Oxygen Luminescence Spectroscopy

Singlet oxygen（¹O₂）is the main cytotoxic substance in type II Photodynamic therapy（PDT）,and its yield plays an important role in the efficacy of PDT.However,the luminescence of ¹O₂ at1270 nm is extremely weak and the quantum yield is low and most detectors have limitations such as low sensitivity and small target surface in the near infrared band,which makes the direct detection based on the luminescence of ¹O₂ at 1270 nm extremely challenging.Therefore,the research work of this paper is as follows:（1）Firstly,this paper has developed a high-sensitivity optical fiber detection system to detect light-sensitized ¹O₂luminescence.The system uses NIR photomultiplier tube,fiber bundle and multi-channel single photon counting board to achieve time-resolved ¹O₂ luminescence spectrum detection.The optical detection performance of the system was evaluated by using Rose Bengal.The results show that the system can obtain the quantitative detection of photosensitized ¹O₂luminescence.As far as the photosensitizer RB aqueous solution is concerned,the detection limit of¹O₂ luminescence of our detection system can reach 3.91 n M.（2）Secondly,this paper studies the application of the system to detect the luminescence characteristics of ¹O₂ in skin tissue optical simulation solution and in vitro porcine skin tissue.The experimental results showed that the ¹O₂ luminescence intensity in the skin tissue optical simulation solution decreases with the increase of optical parameters（μ_a andμ_s）.In vitro pigskin tissue,the increase of the standing time leads to the decrease of the luminescence intensity of ¹O₂.Compared with the photosensitizer aqueous solution,the lifetime value of ¹O₂ increases to 17.4±1.2μs.（3）Finally,based on this system,a study on the dose-effect relationship between the ¹O₂luminescence and the targeted blood vessels PDT response in the auricle skin tissue of mouse was carried out in vivo.The experimental results showed that the ¹O₂ luminescence intensity increased with the increase of photosensitive drug concentration at different doses.In addition,the PDT response of the targeted vessels was observed microscopically after treatment.The results showed that the degree of PDT vascular damage is positively correlated with the intensity of ¹O₂luminescence.In the application of optical fiber detection system in clinical PDT,the results of this study laid a preliminary foundation and are expected to promote the development of optical fiber detection system for clinical PDT dose monitoring.