Fluorescent monolayer boron nitride based quantum dots, including boron nitride quantum dots and boron carbon oxynitride quantum dots, were successfully fabricated via a hydrothermal method by cutting the bulk material assisted by a basic solution. The boron nitride/boron carbon oxynitride quantum dots are water-soluble with uniform lateral sizes around 3.3 and 4.0 nm respectively. The application of the as-prepared quantum dots as promising bio-imaging probes was demonstrated through labeling HeLa cells with boron nitride/boron carbon oxynitride quantum dots, indicating single layered boron nitride/boron carbon oxynitride quantum dots could be further used in biological applications.
