32. A water-sprayable, thermogelating and biocompatible polymer host for use in fluorescent chemical sensing and imaging of oxygen, pH values and temperature
tWe report on the use of a sprayable and thermogelating biomaterial (PoloxamerTM; a.k.a. PluronicTM) inoptical imaging of pH values, local oxygen and temperature. The material is highly biocompatible and easyto handle. We also show that the material is well permeable to oxygen (thus making it a good choice foruse in oxygen sensors), and is stable in liquid solution and at elevated temperature. We demonstrate itsapplicability in optical sensors for oxygen, pH and temperature. This was accomplished by incorporatingappropriate luminescent probes in various kinds of microparticles (which act as hosts for the probesand prevent dye leaching and aggregation), and then dispersing the microparticles in the thermogelatingpolymer. The resulting sensor gels were deposited on the surface of interest via spraying at temperaturesof<20◦C. At these temperatures, the gels adhere well to the target, even on uneven surfaces such as skin,wounds, and bacterial cultures. If temperature is risen to above 25◦C, the gels form a thin and soft butsolid sensing layer which, however, can be simply removed from surface of interest by cooling and wipingit off, or by washing with water. Sprayable thermogelating sensors present obvious advantages over othersensors by not causing damage to the surface of interest. In our perception, the sensing materials alsohave wide further applicability in sensors for other species including clinically relevant gases, enzymesubstrates (such as glucose or lactate) and ions.