Highly selective detection of nitroaromatic explosive 2,4,6-trinitrophenol (TNP) using N-doped carbon dots

Water-soluble fluorescent carbon dots (C-dots) were prepared by a hydrothermal process using guanine as the sole carbon and nitrogen source. The as-prepared C-dots were detailly characterized and discussed. Results demonstrated that C-dots were nearly spherical with an amorphous structure and an average diameter of 2.8 nm. C-dots exhibited a strong blue photoluminescence (26.8% quantum yield) with excitation-dependent properties and good stabilities against pH (6-12), salts and metal ions. Furthermore, C-dots were successfully developed for TNP sensing based on fluorescence quenching in water solution with high selectivity and sensitivity, and the detection limit was as low as 58.5 nM. The unchanged fluorescence lifetimes of C-dots suggested that luminescent quenching effect was predominantly caused by inner-filter effect (IFE). In addition, real sample analysis showed that the as-prepared C-dots had potential applications for the detection of TNP in environment. [GRAPHICS] .