Multifunctional Reduced Graphene Oxide (RGO)/Fe3O4/CdSe Nanocomposite for Electrochemiluminescence Immunosensor

A novel multifunctional reduced graphene oxide (RGO)/Fe 3 O 4 /PDDA/CdSe nanocomposite has been successfully prepared and used as probe for an electrochemiluminescence (ECL) immunosensor of human interleukin-6 (IL-6). The prepared RGO/Fe 3 O 4 /PDDA/CdSe nanocomposite was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–vis) absorption spectroscopy , and a vibrating sample magnetometer (VSM). This nanocomposite shows magnetism, ECL properties, and good biocompatibility. Furthermore, the RGO/Fe 3 O 4 /PDDA/CdSe nanomaterial was applied to develop an ultrasensitive ECL immunosensor for detection of IL-6. The ECL intensity decreased linearly with the IL-6 concentrations in the range 0.002 to 20   ng/mL. Furthermore, the developed ECL immunosensor with high sensitivity, stability and excellent reproducibility can be used for detection of real samples, which make it possible to be used in clinical detection.