One-step synthesis of orange luminescent carbon dots for Ag⁺ sensing and cell imaging

A fast and facile approach to synthesize orange luminescent carbon dots by hydrothermal method, while 1,2-benzenediamine and carbamaldehyde serve as precursors. In order to get stronger fluorescence emission, doping N heteroatoms to make N-CDs. The N-CDs exhibit a high quantum yield of 14.3% along with the fluorescence lifetime of 2.86 ns. Because the emission of N-CDs is quenched by Ag⁺ efficiently, N-CDs can be employed as a highly sensitive and selective detection for Ag⁺ detection and N-CDs were exploited for the determination of Ag⁺ in environmental water samples with satisfactory results. Significantly, using MTT assay, N-CDs have low toxicity against 293 T cells and N-CDs have been applied for A549 cell imaging successfully.