Facile fabrication of network film electrodes with ultrathin Au nanowires for nonenzymatic glucose sensing and glucose/O2 fuel cell

• Ultrathin Au nanowires (AuNWs) with an average diameter of 2 nm were prepared.
• AuNWs can self-assemble into robust network films on common electrodes.
• The network film electrode possesses high electroactive surface area and specific electroactive surface area.
• The network film electrode exhibits high electrocatalytic activity toward glucose oxidation under physiological conditions.
• The network film electrode can be used for high-performance glucose sensing and glucose/O2 fuel cell.

We report here on the facile fabrication of network film electrodes with ultrathin Au nanowires (AuNWs) and their electrochemical applications for high-performance nonenzymatic glucose sensing and glucose/O2 fuel cell under physiological conditions (pH 7.4, containing 0.15 M Cl−). AuNWs with an average diameter of ~7 or 2 nm were prepared and can self-assemble into robust network films on common electrodes. The network film electrode fabricated with 2-nm AuNWs exhibits high sensitivity (56.0 μA cm−2 mM−1), low detection limit (20 μM), short response time (within 10 s), excellent selectivity, and good storage stability for nonenzymatic glucose sensing. Glucose/O2 fuel cells were constructed using network film electrodes as the anode and commercial Pt/C catalyst modified glassy carbon electrode as cathode. The glucose/O2 fuel cell using 2-nm AuNWs as anode catalyst output a maximum power density of is 126 μW cm−2, an open-circuit cell voltage of 0.425 V, and a short-circuit current density of 1.34 mA cm−2, respectively. Due to the higher specific electroactive surface area of 2-nm AuNWs, the network film electrode fabricated with 2-nm AuNWs exhibited higher electrocatalytic activity toward glucose oxidation than the network film electrode fabricated with 7-nm AuNWs. The network film electrode exhibits high electrocatalytic activity toward glucose oxidation under physiological conditions, which is helpful for constructing implantable electronic devices.