Porous redox-active Cu2O–SiO2 nanostructured film: Preparation, characterization and application for a label-free amperometric ferritin immunosensor

A novel Cu2O–SiO2 nanostructured particle was synthesized by a solution-phase method and was adopted for construction of a label-free amperometric immunosensor. The porous Cu2O–SiO2 nanoparticles had good redox electrochemical activity, large surface-to-volume ratio, film-forming ability and high stability. The physical morphology and structure of Cu2O–SiO2 nanoparticles were examined by scanning electron microscope (SEM) and transmission electron microscopy (TEM). The chemical component of Cu2O–SiO2 was confirmed by X-ray photoelectron spectroscopy (XPS) and auger electron spectra (AES). The electrode modification process was probed by cyclic voltammetry (CV) and the performance of the immunosensor was studied by differential pulse voltammetry (DPV) measurements. To improve the analytical characteristics of the immunosensor, the experimental conditions were optimized. The immunosensor exhibited a good response to ferritin in ranges from 1.0 to 5.0 and 5.0 to 120.0 ng mL−1 with a detection limit of 0.4 ng mL−1. The fabricated immunosensor could make a low-cost, sensitive, quantitative detection of ferritin, and would have a potential application in clinical immunoassays.