Sugarcoated haws on a stick-like MWNTs-Fe3O4-C coaxial nanomaterial: Synthesis, characterization and application in electrochemiluminescence immunoassays

In this paper, a carbon coated magnetic nanoparticle (Fe3O4-C) was first synthesized via solvothermal reaction and carbonization of glucose under hydrothermal condition. The electrochemiluminescence (ECL) property of Fe3O4-C was studied, and exhibited a peak at 1.21 V. In the goal to amplify the ECL intensity for sensitive detection, a novel coaxial carbon coated magnetic nanomaterial (MWNTs-Fe3O4-C) was synthesized. Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), powder X-ray diffraction (XRD) and powder X-ray photoelectron spectrometry (XPS) were applied as powerful tools to characterize and to demonstrate the named nanomaterial. MWNTs-Fe3O4-C showed better ECL property than Fe3O4-C. Furthermore, an ultrasensitive ECL immunosensor based on MWNTs-Fe3O4-C was developed for the determination of carcinoembryonic antigen (CEA). The prepared ECL immunosensor exhibited high sensitivity, good reproducibility, long-term stability, and acceptable precision on the detection of CEA in clinical human serum samples. (C) 2013 Elsevier B.V. All rights reserved.