DNA based click polymerization for ultrasensitive IFN-γ fluorescent detection

Abstract

With the demanding of low abundance biomolecule detection increase, to develop novel signal amplification strategies and simple, convenient, sensitive sensors are necessary for ultrasensitive bioassays in disease diagnosis, drug therapy and environmental monitoring. Herein, for the first time, a new “aptamer/protein/aptamer-polymer” supersandwich fluorescence sensor for the ultrasensitive protein detection via DNA based click polymerization was fabricated. During the fabrication process, a new fluorescent DNA click reactant was prepared through a quick, gentle and spontaneous combination of two DNA fragments. Functionalized Fe3O4 magnetic nanoparticles provide abundant sites due to their large surface area, and enable the sensor prepared easily, without the need for complicated synthesis and purification steps. Under optimal conditions, this proposed supersandwich strategy could detect IFN-γ protein down to 0.175 fM with a broad concentration range from 0.01 pM to 10 nM. Meanwhile, good detection limit of 1.63 fM in fetal bovine serum indicates that this convenient, sensitive and high selective sensor shows a great potential in clinical ultrasensitive protein detection.