Hybridization of FePt/ZnS Nanocore-Shell Structure with DNAs of Different Sequences

Abstract

This study attempts to develop a nanocore-shell structure with photomagnetic nature. The structure is then allowed undergo conjugation reaction with the DNAs of different sequences so that it can be applied to target-based drug therapy and biomedical-related areas. First of all, iron platinum (FePt) magnetic nanofluid with an average particle size of 2–3 nm is prepared by a chemical method. After that, zinc sulfide with a fluorescent nature is used to modify the surface of the nanoparticles so as to form a core-shell structure. The shell thickness in this kind of core-shell structure can be controlled at 5–10 nm by a fabrication process. The FePt nanoparticles being modified by zinc sulfide not only can enhance the dispersed suspension of nanoparticles, but also have good optical nature. The prepared nanocore-shell structured particles are conjugated with two groups of DNA of different sequences respectively. Nanoparticles before and after being conjugated and the structure of DNA are not deteriorated or altered because of the principle of positive and negative charges attraction. Conjugation efficiency is 64% and 77% respectively. A bridge DNA and two groups of DNA of different sequences are conjugated. Moreover, the occurrence of hybridization is proven through the analyses of the UV-vis spectrum. Analyses by fluorescence spectrometer show that the luminescence for modified ZnS and nanoparticles after hybridization respectively increases significantly.