Synthesis of patterned nanogold and mesoporous CoFe2O4 nanoparticle assemblies and their application in clinical immunoassays.

Herein, we describe a facile and feasible synthesis method for patterning nanogold particles onto magnetic mesoporous CoFe(2)O(4) nanostructures (Au-MMNs) by using poly(vinyl pyrrolidone) (PVP) as cross-linker. Initially, mesoporous CoFe(2)O(4) nanoparticles were initially synthesized with a thermal decomposition method by using mesoporous silica nanoparticles as templates, and then nanometre-sized gold particles were produced through the in situ reduction of the Au(III) on the PVP-functionalized CoFe(2)O(4). The as-prepared Au-MMNs were characterized by transmission electron microscopy (TEM), N(2) adsorption-desorption isotherms, UV-visible adsorption spectrometer, vibrating sample magnetometer (VSM) and X-ray photoelectron spectroscopy (XPS). Furthermore, we also demonstrate the conjugation capacity of the synthesized Au-MMNs toward biomolecules by using quartz crystal microbalance (QCM), and the possible application in the electrochemical immunoassays. Experimental results indicated that the resulting Au-MMNs display good conjugation capability toward the biomolecules, and excellent analytical properties for determination of target molecules. © The Royal Society of Chemistry 2011