Tailored anisotropic magnetic conductive film assembled from graphene-encapsulated multifunctional magnetic composite microspheres

Abstract

Due to the fast electron transportation and good biocompatibility, the use of graphene in biosensors is becoming more and more appealing. But a key challenge is how to obtain well-organized 2D or 3D graphene structures to build larger objects, and the development of methods for controlling the organization of functional objects on a nanometre scale to build larger objects is of fundamental and technological interest. To overcome this problem, we demonstrate a novel strategy for the fabrication of a reduced graphene oxide-encapsulated multifunctional magnetic composite microspheres (rGOE-Ms)-based anisotropic conductive film (ACF). The well-designed rGOE-Ms possess both magnetization and good electron transport properties. Magnetic properties can be detected by their movement in the gel film under an external magnet. Most interestingly, the prepared gel film has displayed the existence of rGOE-Ms alignment and anisotropy in the ACF, and the electrical resistivity of the vertical ACF was almost fifteen times higher than the horizontal. Therefore, the ACF can be extended to various advanced applications, such as chemical/biosensors, nanoelectronics, and so on.