Enzyme-Free Amperometric Detection of Glucose on Platinum-Replaced Porous Copper Frameworks

With respect to a nonenzymatic electrochemical sensor for detection of small biomolecules like glucose, it is well recognized that an interface with highly electrocatalytic properties is desired. Our previous studies have demonstrated that porous Cu foams from hydrogen evolution assisted electrodeposition could provide beneficial structures for large active surface and mass transfer in glucose sensing (Biosens. Bioelectron., 2014, 51: 22-28), and decoration of micro-scale Pt cubes on this multiaperture substrate through manipulative deposition offered exciting activity and stability for electro-catalyzing glucose in neutral media (Chem. Eur. J., 2013, 19: 9534-9541). On the basis of these results here we further cover the porous Cu frameworks with a Pt monolayer through the galvanic replacement reaction, and fabricate a new electrochemical interface for high-performance determination of glucose. The sensing surface was facilely assembled by firstly electrodepositing porous Cu architectures with hydrogen evolution and then galvanically replacing the surface layer with Pt, and was well characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and energy dispersive spectroscopy. It was found that the unilaminar Pt-replaced Cu frameworks, with the profitable reaction surface derived from porous skeletons and the underlying activity of Pt-support composites, could supply the highly electrocatalytic oxidation of glucose in phosphate buffer solution (pH 7.4). As a result, the prepared enzymeless sensor provided linear amperometric responses for glucose in the concentration scope of 1∼11 mM, with a high sensitivity of 9.62 μA cm−2 mM−1.