Optoelectronic Properties And Biophotonic Applications Of Black Phosphorus/black Phosphorus-like Two-dimensional Materials

Nowadays,cancer has become one of the greatest threats to human health.However,traditional therapies often show serious side effects.As a result,many researchers turned their attention to biophotonics,using optical methods to diagnose and treat cancer.With the unique energy band structure,biodegradability and many other excellent properties,black phosphorus has shown attractive prospects in the field of biophotonics.In this article,we introduced relevant background knowledge and studied the photoelectric properties and biophotonic applications of black phosphorus and black phosphorus analogue two-dimensional materials.The main contents are as follows.1.Tellurium nanosheets were prepared by liquid-phase exfoliation.Like black phosphorus,this material also exhibits significant anisotropy.We explored the effects of various parameters on the physical properties of the nanosheets.After that,we measured the photoelectric response performance of tellurium nanosheets using a standard three-electrode system.This device can realize self-powered photoelectric response without external voltage.In addition,adjusting voltage,optical power intensity and electrolyte concentration can further improve the device’s optical response performance.Our work can provide ideas for the preparation of other chain structure two-dimensional materials.At the same time,our research on the photoelectric properties of tellurium nanosheets also shows that this material is expected to be used in biosensors and photodetectors.2.We obtained the exosomes from tumor cells and use it to coat black phosphorus quantum dots.The characterization shows that the encapsulation is very successful.The obtained composite material shows obvious broadband light absorption and photothermal performance.In vitro experiments prove that this material has good biocompatibility and photothermal killing effect.in vivo experiments proved that exosomes improved the targeting ability and the retention time at the tumor site.3.We designed a drug delivery system based on tin sulfide nanosheets.The tin sulfide nanosheets have a fold structure similar to black phosphorus,which is beneficial to the drug loading.Our experimental data shows that tin sulfide nanosheets have good biocompatibility and excellent photothermal performance.Its photothermal conversion efficiency at 808 nm is 39.3%.In addition,It was also found that tin sulfide nanosheets show high loading of small molecules such as doxorubicin(DOX)(up to ～200% in weight).In vitro experiments prove that the tin sulfide drug delivering platform showed a synergistic therapeutic effect through the combination of photothermal therapy and chemotherapy.In vivo experiments also confirmed the efficacy and low side effects of the photothermal / chemotherapy combination therapy based on tin sulfide nanosheets.Our research shows that tin sulfide nanosheets can be used to fabricate novel photothermal agents and drug delivery platforms.