Preparation of carbon dots with orange emission for Cr(Ш) detection and cellular imaging

A new type of orange emission carbon dots (OCDs) was prepared by hydrothermal method using 1,2,4‐triaminobenzene and p‐aminobenzenesulphonic acid as precursors. TEM characterization showed that the new OCDs were uniform in size with an average particle size of 4–7 nm. Infrared spectroscopy and XPS analysis showed that the surface of the OCDs were rich in hydrophilic functional groups. Fluorescence spectroscopy results showed that the obtained OCDs exhibited excellent fluorescence with an absolute quantum yield as high as 14.9%. The OCDs were further applied to the detection of metal ions. It was found that the fluorescence of OCDs could be effectively quenched by Cr(Ш) with a detection limit of 0.38 μm. Notably, the obtained OCDs have been successfully used for fluorescence detection of Cr3+ ions in cell level.