Ultrasmall Black Phosphorus Quantum Dots: Synthesis and Use as Photothermal Agents

Black phosphorus quantum dots (BPQDs) were synthesized using a liquid exfoliation method that combined probe sonication and bath sonication. With a lateral size of approximately 2.6 nm and a thickness of about 1.5 nm, the ultrasmall BPQDs exhibited an excellent NIR photothermal performance with a large extinction coefficient of 14.8 Lg−1 cm−1 at 808 nm, a photothermal conversion efficiency of 28.4 %, as well as good photostability. After PEG conjugation, the BPQDs showed enhanced stability in physiological medium, and there was no observable toxicity to different types of cells. NIR photoexcitation of the BPQDs in the presence of C6 and MCF7 cancer cells led to significant cell death, suggesting that the nanoparticles have large potential as photothermal agents. Quantenpunkte aus schwarzem Phosphor wurden durch Flüssigexfoliation synthetisiert. Sie zeichnen sich durch einen hohen Extinktionskoeffizienten von 14.8 Lg−1 cm−1, eine photothermische Umwandlungseffizienz von 28.4 % und gute Biokompatibilität aus und können daher als photothermische Agentien in der Krebstherapie eingesetzt werden.