Integrated Luminescent Lifetime System for Continuous Oxygen Monitoring

This study proposes a fully integrated optical sensing platform based on photoluminescence lifetime measurements, for continuous monitoring of tissue oxygen levels. The platform incorporates silicon light-emitting diodes (SiLEDs), single-photon avalanche diodes (SPADs), and a functionalized phosphorescence layer using platinum octa-ethyl porphyrin (PtOEP). This paper details the characterization of SiLEDs, improvements in the data acquisition system for enhanced time resolution, and the experimental procedure for oxygen detection. The results demonstrate the sensor's sensitivity to oxygen concentrations, particularly below 20%. Stern-Volmer analysis confirms the platform's linearity and sensitivity to oxygen with an R-squared of 0.9330, making it a promising tool for monitoring oxygenation in diverse microenvironments, including tumorous tissues.