Temperature-Dependent Dual Emission from Sucrose-Derived Carbon Nanodots: A Ratiometric Fluorescent Thermometer

Carbon nanodots (CNDs) with conspicuous dual emission (at 450 and 517 nm) were fabricated by hydrothermal treatment of aqueous sucrose solution. The temperature-dependent photoluminescence (PL) and time-resolved PL were investigated. The trapping of excited electrons by the nonradiative defects should substantially account for the PL quenching as the temperature increases. The sucrose-derived CNDs show great potential for applications as ratiometric fluorescent thermometers with a sensitivity of approximately 2.15% degrees C-1.