A singlet oxygen monitor as an in vivo photodynamic therapy dosimeter

Abstract

In this paper we describe the development and testing of instruments to measure singlet molecular oxygen produced by the photodynamic process. Singlet oxygen is an active species in photodynamic therapy, and we are developing two instruments for PDT researchers with the goal of a real-time dosimeter for singlet oxygen. We discuss both an ultrasensitive point sensor, and an imaging system that provides simultaneous 2D maps of the photosensitizer fluorescence and the singlet oxygen emission. Results of in vitro tests to characterize the sensors and preliminary in vivo results are presented.