Hyper-Branched Cu@Cu2O Coaxial Nanowires Mesh Electrode for Ultra-Sensitive Glucose Detection

Abstract

Electrode design in nanoscale is expected to contribute significantly in constructing an enhanced electrochemical platform for a superb sensor. In this work, we present a facile synthesis of new fashioned heteronanostructure that is composed of one-dimensional Cu nanowires (NWs) and epitaxially grown two-dimensional Cu2O nanosheets (NSs). This hierarchical architecture is quite attractive in molecules detection for three unique characteristics: (1) the three-dimensional hierarchical architecture provides large specific surface areas for more active catalytic sites and easy accessibility for the target molecules; (2) the high-quality heterojunction with minimal lattice mismatch between the built-in current collector (Cu core) and active medium (Cu2O shell) considerably promotes the electron transport; (3) the adequate free space between branches and anisotropic NWs can accommodate a large volume change to avoid collapse or distortion during the reduplicative operation processes under applied potentials. The above three proposed advantages have been addressed in the fabricated Cu@Cu2O NS-NW-based superb glucose sensors, where a successful integration of ultrahigh sensitivity (1420 μA mM–1 cm–2), low limit of detection (40 nM), and fast response (within 0.1 s) has been realized. Furthermore, the durability and reproducibility of such devices made by branched core–shell nanowires were investigated to prove viability of the proposed structures. This achievement in current work demonstrates an innovative strategy for nanoscale electrode design and application in molecular detection.