Optical sensors based on stimuli responsive polymer have attracted great attention due to their fast response time and reversible conformation changes depending on pH, temperature, ionic strength, light or electric field. Particularly, optical sensors based on temperature responsive polymers are getting the spotlight due to their ability of remote sensing and monitoring temperatures in microscopic domains, where conventional thermometer cannot be used. However, such sensors are typically limited to the detection of a narrow temperature range because temperature responsive polymers change their chain conformation sharply around its lower critical solution temperature (LCST), although the temperature sensing in a range between 25-45 oC is of particular importance in clinical and biological application. Moreover, most thermometer generally produce a response to thermal stimuli through a single photoluminescence intensity change that requires an expensive PL detector because of difficult detection. Herein, we developed efficient colorimetric thermometer that detects a wide range temperature from 24-42 oC by distinct color change. The thermometer is based on graphene oxide (GO) functionalized with three kinds of block copolymers (BCPs). All three different BCPs are composed of temperature responsive block and fluorescent dye block, but each temperature responsive block has different LCST for detecting different but complimentary range of temperatures. Also, three BCPs have different emitting colors of red, green and blue to provide a distinct colorimetric response of the thermometer. Therefore, the fluorescent intensity of three BCPs on GO platform was were controlled independently by three linkers which have different LCST as the temperature changes from 24 to 42 oC and three BCP-integrated GO (MP-GO) showed a distinct colorimetric behavior from white, green, to red in range of 24-42 oC. Importantly, the MP-GO sensor exhibited excellent reversibility and dispersion stability in water, indicating that our system is an ideal platform for clinical and biological applications.

Efficient, colorimetric, wide-range temperature sensor based on fluorescent, block-copolymer, functionalized graphene oxide

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.