Recent advances in functional bismuth chalcogenide nanomaterials: Cancer theranostics, antibacterial and biosensing

In recent years, the research of bismuth chalcogenide (Bi2X3, X = O, S, Se, and Te) nanomaterials has expanded from the fields of optics, chemical, and electronic engineering to the biomedical, due to its easy preparation and modification, low cost, high stability, controllable morphology, and low toxicity. As an anti-magnetic heavy metal, Bi2X3 has various characteristics such as good X-ray attenuation coefficient, high near-infrared absorbance, excellent photothermal conversion efficiency, and photocatalytic performance, making it play an important role in diagnostic imaging, photothermal therapy, radiotherapy, synergistic therapy of cancer, antibacterial and biosensor. Bi2X3 can improve biocompatibility and other specific properties by simply modifying its surface to play the desired function. The good anti-tumor and anti-bacterial effects under near-infrared laser irradiation and the photocatalytic performance of biosensors are the main biomedical research fields of Bi2X3, which open opportunities for its future clinical transformation. In this review, we summarize the synthesis of Bi2X3 with different sizes, morphology, and composition and its application in the biomedical field. In addition, the current challenges and opportunities of Bi2X3 are also discussed.