Fibrous Phosphorus Quantum Dots for Cell Imaging

Fibrous phosphorus is a crystalline structure belonging to the extensive family of phosphorus allotropes. The material's structure consists of 1D tubular layers held together by van der Waals forces and is a semiconductor with an optical band gap of 2.1 eV in its bulk form. With these properties in mind, we developed a facile solution-based method for the fabrication of fibrous phosphorus quantum dots (FPQDs). The FPQDs were prepared by sonicating the material in N-methylpyrrolidone and centrifuging to separate by size. The average size of the quantum dots is 3.8 +/- 0.9 nm with a height profile of 2.7 +/- 1.3 nm. The as-prepared FPQDs show fluorescence properties with emission in the indigo-blue region and a band gap of 3.3 eV and show remarkable stability when exposed to air and light. As a proof-of-concept of its properties, we used FPQDs as a fluorescent label in the bioimaging of human adenocarcinoma cells.