A naphthalimide-based thermometer: heat-induced fluorescence “turn-on” sensing in a wide temperature range in ambient atmosphere†
A heat-induced fluorescent “turn-on” sensor based on naphthalimide, NapPT-1, in which thioether chains were joined at the 4-site of naphthalimide, was designed and synthesized. NapPT-1 can act as a temperature sensitive sensor due to the PET inhibition process, and displays obvious “turn-on” fluorescence emission which increases gradually within the temperature range from −20 to 150 °C. NapPT-1 has good reversibility from 20 to 100 °C and can work effectively in a wide temperature range. A variable temperature experiment on NapPT-1 in polymer film verified that NapPT-1 has good practicability.