Changes in temperature can lead to serious problems, such as when electronic devices overheat, or in food storage, where fluctuations can lead to unsafe food. Temperature-responsive materials could provide a simple method for detecting unwanted temperature fluctuations.
In their article in Advanced Functional Materials, Dr. Claudio Roscini from the Catalan Institute of Nanoscience and Nanotechnology (ICN2), Consejo Superior de Investigaciones Científicas (CSIC), and the Barcelona Institute of Science and Technology (BIST), and colleagues develop nanoparticle (NP)-based fluorescent temperature sensors.
Rhodamine B dye and dodecanoic acid were encapsulated in polymeric NPs. Above a threshold temperature the NPs underwent a structural change, which lead them to fluoresce.
Increasing and then decreasing the temperature beyond the threshold temperature demonstrated irreversible fluorescence, making these NPs suitable for recording the thermal history of surfaces.
By varying the polymer, the threshold temperature could be controlled, and very high temperatures, up to 200 °C, could be detected, demonstrating applicability of this method for various applications.