N-doped red emission carbon dots and detection of Fe3+

Abstract

So far, the fluorescence emission wavelength of carbon dots has been mostly concentrated in the blue-green area, while the number of carbon dots which emit red light is small. However, carbon dots with long wavelength emission are urgently needed in the many fields such as biological imaging and detection. Here, we synthesized an N-doped red emission carbon dots (r-CDs) by a simple, green hydrothermal method in one step. The prepared carbon dots have many superior properties such as high alcohol solubility, emission independent of excitation, high stable optical property and highly sensitive and selective to Fe3+. Dispersed the r-CDs into the ethanol, the fluorescence emission spectrum of the r-CDs showed red emission with a main peak at 600 nm and a shoulder peak at 640 nm. And the QY of the r-CDs is 7.1 %. Through various structural characterization methods, the red emission was attributed to the surface state emission caused by a large number of N-containing functional groups on the surface. The r-CDs are selective to Fe3+ and have good sensitivity to Fe3+ within a certain concentration of 5—120 mmol/L. The r-CDs can be used as an unmodified detection probe for Fe3+. More importantly, the r-CDs were successfully used as a probe for the rapid detection of Fe3+ in tap water and got good detection results.