Optical sensors are widely used in many applications, including in telecommunications, environmental monitoring, industrial automation, and medical devices. An important class of optical sensors uses fluorescent compounds as the basis for their detection mechanism thanks to their numerous benefits including high specificity, low detection limits, fast response time, and technical simplicity. Fluorescent sensors typically work by exhibiting a change in their emission, such as fluorescence intensity, emission wavelength or lifetime, in response to interactions with specific analytes or environmental changes. Organic fluorescent compounds such as rhodamines, fluoresceins , cyanine, BODIPY, and coumarin dyes have long been used in optical sensing. Phosphorescent complexes have also been explored as sensors in oxygen sensing, metal ion detection, biomolecule detection, and temperature sensing. Indeed, both oxygen and temperature sensing rely in particular on accessible triplet excited states of the sensor.