Study On Improvement Of Photothermal Properties Of Nano-Fe₃O₄

Nano-Fe₃O₄ has been widely used in many fields such as bioseparation,immunoassay,magnetic resonance imaging,magnetic heat treatment and drug-targeted transport because of its good biocompatibility,strong magnetic response and clear metabolic pathway.Recently,the photothermal properties of nano-Fe₃O₄ have been developed and have been developed in the field of near-infrared photothermal therapy and solar collectors.However,the results of the present study also show that the absorption of Fe₃O₄ in the near-infrared region is relatively weak and always requires the use of high power lasers or high dose can get the ideal photothermal effect.In this paper,the near-infrared absorption of nano-Fe₃O₄ is improved by constructing Fe₃O₄ clusters and introducing organic dye molecules as the absorption antenna.The photothermal properties of nano-Fe₃O₄ are optimized.The main research contents are as follows:?1?Fe₃O₄ nanoparticles were prepared by high-temperature solution phase reaction.We obtain the Fe₃O₄ clustersby self-assembly of Fe₃O₄ nanoparticles via the interaction between solvents.We effective adjust the size of the nanoparticle clusters by changing the chain length of the surfactant.This nanoparticle clusters maintain strong superparamagnetic at room temperature,achieving rapid magnetic separation.Compared with Fe₃O₄ nanoparticle,the absorption of Fe₃O₄ nanoparticle clusters at 808 nm is enhanced by 96 times,the photothermal effect is improved by nearly 2 times,and the larger the size of the nanoparticles is,the better the photothermal effect is.In addition,the increased of concentration of nanoparticle clusters and the laser power density also contribute to the improvement of their photothermal properties.The results of cell experiments confirmed that Fe₃O₄ nanoparticle clusters could effectively kill cancer cells under the near infrared light irradiation.This study provides a new idea for the design and construction of an efficient,low-toxicity nano-photothermal treatment platform.?2?In order to improve the near-infrared photothermal properties of nano-Fe₃O₄,we synthesized the near-infrared dye IR-806 and successfully prepared Fe₃O₄/IR-806 composite nanoparticles by ligand exchange method.By adjusting the addition of Fe₃O₄ nanoparticles and IR-806,it was found that the maximum number of dyes connect a single Fe₃O₄ nanoparticle was about 5.4.The absorption of Fe₃O₄/IR-806 composite nanoparticles is about 8.5 times that of Fe₃O₄ nanoparticles at 808 nm.The photothermal effect of Fe₃O₄ nanoparticles is about 1.7 times and the photothermal conversion efficiencycould be achived 12.7%,andthe increased of mass of nanocomposites and the laser power density also contribute to the improvement of their photothermal properties.The photothermal effect of composite nanoparticles was 1.3 times that of Fe₃O₄ nanoparticles aloneunder simulated sunlight irradiation.The study provides a useful reference for the improvement of the photothermal of nano-Fe₃O₄ and promote its practical process.