Hair-derived carbon dots toward versatile multidimensional fluorescent materials

We report a simple and green route to the fabrication of fluorescent carbon dots (CDs), and demonstrate their versatile applications. Hair, a kind of natural and nontoxic raw material, was chosen as the precursor to prepare CDs via a one-step pyrolysis process. The structure and fluorescence properties of the CDs were thoroughly investigated. The obtained CDs can emit bright blue light under UV light with the quantum yield of ca. 17%, and exhibit excitation-, pH- and solvent-dependent fluorescence. The functional groups on the surface of CDs confer these nanomaterials with excellent dispersibility in water and most polar organic solvents, as well as good compatibility with polymer matrices such as poly(methyl methacrytate) and potyvinylpyrrolidone. Then multidimensional CD-polymer hybrid materials, including one-dimensional (1D) microfibers, 2D patterned films and 3D microbeads were constructed with excellent overall performance, which are useful in fluorescent patterns, flat panel displays and anti-counterfeiting labeling fields.