The invention discloses a
nitrogen-
sulfur-doped efficient
red light emission
carbon dot, a preparation method and application thereof. The preparation method comprises the following steps: (1) by taking phenylenediamine as a
carbon source and a
nitrogen source and
thiocyanic acid and a derivative thereof as a
sulfur source, dissolving the phenylenediamine and the
sulfur source in a water solution according to a certain proportion; (2) transferring the
mixed solution into a high-pressure reaction kettle, putting the high-pressure reaction kettle into a
drying oven, preserving heat for 6-18 hours at 120-220 DEG C, and carrying out
hydrothermal reaction treatment; and (3) cooling to
room temperature, centrifuging the original solution of the carbon dots, dialyzing and purifying to obtain the carbon dots. According to the invention, the synthesis
route is simple, the raw materials are wide in source and low in price, purification is easy, and the obtained
red light carbon dots have the characteristics of good
biocompatibility, good water
solubility, high stability,
low toxicity and the like, have excellent tissue penetrability and have unique advantages in
biological cell, in-vivo imaging and other related biomedical applications.