Multi-sensor system based on phase detection, an LED array, and luminophore-doped xerogels

An optical multi-sensor system based on the excited-state lifetime of luminophore doped xerogels is described. The system is based on the novel concept of combining addressable surface-mount light-emitting diode (SM-LED) arrays with doped xerogel thin films; each SM-LED in the array is coated with a different xerogel-based sensor element. Each sensor element exhibits a unique response profile to the target analyte. A prototype system with a 2×2 LED array is presented, with three of the LEDs coated with xerogel-based sensing layers, each layer having a different sensitivity and response profile to oxygen (O₂).