One-Pot Synthesis of Deep Blue Hydrophobic Carbon Dots with Room Temperature Phosphorescence, White Light Emission, and Explosive Sensor

Bright luminescent hydrophobic carbon dots receive significant attention on account of their potential utility in bio-imaging, sensors, and creating a full range of colors in displays. Herein, the solvothermal one-pot synthesis of nitrogen and sulfur-doped hydrophobic carbon dots (HCDs) from a single precursor, is reported. These HCDs exhibit good dispersibility in different organic solvents and show blue fluorescence in solid and solution states. Notably, HCDs show green color room temperature phosphorescence emission centered at 515 nm with a long average lifetime of 1.1 ms and an ultralong lifetime of 334 ms at 77 K. An intense white light with Commission international de d'Eclairage chromaticity coordinate of (0.32, 0.34) is generated by a simple mixing of HCDs with rhodamine 6G in the solution state. Furthermore, these HCDs are explored for the rapid detection of extremely hazardous and strong explosive picric acid in a non-aqueous solution with a limit of detection of 3.2 µm and good selectivity.