Synthesis Of MnFe₂O₄ Mesoporous Nanomaterial And Its Application In Artemisinin Loading And Mercury Ion Detection

Mesoporous nanomaterials have been used extensively in catalysis,electrochemistry and adsorption,owing to the distinct properties of high surface area,easy morphology tuning,and regularly porous structure et al.Mn Fe₂O₄ nanomaterials have attracted wide attention because of strong magnetic property and the special spinel structure of AB₂O₄.In this project,a new kind of mesoporous Mn Fe₂O₄ magnetic nanosphere?MMS?were successfully synthesized to load traditional Chinese drug-artemisinin?ART?.The loading and selective release efficiency of ART based on MMS were investigated.Moreover,a novel Hg²⁺colorimetric detection method based on MMS was proposed according to the strong influence of Hg²⁺on the catalytic activity of MMS nanozyme.The detailed work was introduced as followed:1. A new kind of mesoporous Mn Fe₂O₄ magnetic nanosphere?MMS?with good monodispersity were synthesized based on solvothermal method.X-ray diffraction?XRD?,high-resolution transmission electron microscope?HRTEM?,scanning electron microscope?SEM?and other instruments were used to characterize the synthesized MMS.The results showed that the surface charge of MMS is positive,and their average size is 180 nm with an average pore size of 7.6 nm.MMS were used to load ART because of the porous structure.The loading efficiency reaches up to 30 wt%under the optimized condition.In addition,the established MMS nanocarrier was expected to provide not only extra Mn²⁺thus enhancing the chemotherapy effect of ART,but realize the synergy of chemotherapy and chemodynamic therapy.2. It was found that MMS can catalyze hydrogen peroxide-induced oxidation of3,3',5,5'-tetramethylbenzidine?TMB?,and this catalytic activity of MMS can be inhibited by mercury ions(Hg²⁺).Hence,a novel method for rapid detection of Hg²⁺was established.The linear range of this method for Hg²⁺detection was 0.05-5 nmol/L.In addition,samples of the Hg²⁺in lake water were detected,and the recovery rate was between 96.5%and 105.0%with a relative deviation of less than 2.5%.Furthermore,the reason for Hg²⁺induced inhibition of catalytic activity of MMS nanozyme was confirmed by X-ray photoelectron spectroscopy?XPS?.The result showed that Hg²⁺can be reduced to mercury substance in the reaction system,and eventually the reduced mercury substance deposited on the surface of MMS nanozyme,resulting in the inhibition of MMS nanozyme's catalytic activity.This method has certain reference value for the development of fast and highly sensitive sensor for Hg²⁺.