Synthesis Of Au NRs@MOFs And Their Photothermaland Chemical Kinetic Properties

The problem of cancer treatment has become one of the most important challenges facing the current biomedical field.In recent years,cancer treatment methods based on the photothermal properties of nanomaterials have stimulated the enthusiasm of researchers worldwide.Gold nanorods are favored by scientists because of their high photothermal performance and outstanding biocompatibility.However,the tip ablation of gold nanorods is easy to occur at higher temperatures,resulting in morphological changes,which affect their light absorption and photothermal properties.As a result,improving the photothermal stability of gold nanorods has become the key to its application in photothermal anti-tumor.On the other hand,Fe-based MOFs can generate a Fenton reaction in the tumor microenvironment and generate hydroxyl radicals,which can be used in chemodynamic therapy of tumors.Considering the characteristics of gold nanorods and Fe-based MOFs,the gold nanorods coated with Fe-based MOFs are expected to have photothermal and chemical dynamic synergistic therapeutic properties,and can effectively improve the photothermal stability of gold nanorods.Based on this,this paper studies the synthesis of Au NRs@MOFs and its photothermal and chemical kinetic properties.Gold nanorods were prepared by a seed method,and their morphologies and light absorption characteristics were characterized by electron microscopy,UV-vis-NIR and dynamic light scattering instruments.Gold nanorods with an aspect ratio of about 4:1 were prepared,presenting uniform particle size distribution and high absorption peak at 808 nm.Under the 808 nm laser irradiation with a power density of 2.0 W/cm²,the photothermal heating characteristics of the gold nanorod dispersion were studied.The resultys revealed that after 6 minutes of irradiation,the gold nanorod dispersion with a concentration of 100 ?g/m L can be heated from28.2 °C to 56.8 °C,but after three photothermal cycles,its photothermal characteristics were declined.The Fe-based MOFs were respectively prepared by a high temperature hydrothermal method and a 40 °C oil bath method,and then the gold nanorods were coated with the MOFs material.The controllable fabrication of Au NRs@MOFs nanoparticles was achieved by adjusting the reaction time,drug dosages and the other experimental conditions.Photothermal testing showed that Au NRs@MOFs nanoparticles can be heated to 54.4 °C by irradiating 2.0 W/cm² 808 nm laser for 10 min.Although its photothermal performance is slightly lower than that of the puregold nanorods,the photothermal cycle stability of Au NRs@MOFs nanoparticles has been significantly.Chemical kinetic tests have shown that the outer shell can react with GSH and H₂O₂ to effectively produce ·OH.Therefore,the Au NRs@MOFs nanoparticles prepared in this work have a photothermal-chemical dynamic synergistic treatment effect,presenting good application prospects for the clinical treatment of cancer.