Optochemical Sensors Based on Luminescence

The aim of this contribution to the Encyclopedia of sensors is to provide the reader the basic principles of lifetime-based optochemical sensors focusing on phase-modulation fluorometry as the measurement principle. Chapter 2 deals with detection principles for luminescence based sensors, where the differences between intensity and luminescence lifetime (time-domain and frequency-domain) measurements are described. Chapter 3 discusses instrumentation for the phase measurement technique focused on the principle set-up of phase measurements, different phase detection principle and limiting factors for performance of phase measurements as well as optical components in instrumentation set-up. Last Chapter 4 describes sensor schemes for lifetime-based optochemical sensors using the phase-modulation method. This chapter reviews chemical detection principles bused in lifetime-based sensors for monitoring pH, oxygen and carbon dioxide.