Facile preparation of a hollow core-shell nanocomposite for the ultrasensitive sensing of glucose

A core-shell Cu(OH)(2)@Au@Co(OH)(2) nanocomposite with hollow nano-flower morphology fabricated by a facile and non-surfactant template-engaged reaction was applied for highly sensitive detection of glucose. The prussian blue analogues (PBA) of core-shell nanocubes (CuFe@Au@CoFe) were synthesized as the template through the accurate control of the reaction rate. In this nanocubes, Au nanoparticles for accelerating electron transfer rate were reduced at the interface of CoFe (core) and CuFe (shell) to improve their conductivity. These nanocubes were then etched controllably to form three-dimensional hollow nanoflowers stacked by nanosheets. It provided abundant electrode-electrolyte channels and high surface areas for OH- and glucoses adsorption and the following reactions. Due to the sandwich structure and synergic effect of the nanomaterials, the as-prepared sensors exhibited an ultrahigh sensitivity of 3427 mu A mM(-1) cm(-2) for glucose detection, as well as a wide linear range of 0.001-5.2 mM with a low detection limit of 0.5 mu M. In addition, the Cu(OH)(2)@Au@Co(OH)(2) nanocomposite showed long-term stability and good reproducibility for glucose detection in serum with comparable results as measured with commercial glucometer. We believe the nanocomposite provided a good candidate for glucometer in future clinical applications.