It is urgent to develop highly active catalysts toward hydrogen peroxide (H 2 O 2 ) sensor in many industrial and biological processes, which usually is limited by high cost of instrumentation requirements and low-accuracy detection at low level. Herein, Cu 2 O@Cu 9 S 5 yolk-shell nanospheres has been synthesized via a facial wet chemical method and applied as electrocatalyst for non-enzymatic H 2 O 2 sensor. These Cu 2 O@Cu 9 S 5 yolk-shell nanospheres with mean sizes of 230 nm consisting of Cu 2 O conductive core and Cu 9 S 5 shell show numerous advantageous characteristics of well-sustained structural integrity, the homogeneous particle size distribution and visible mesoporosity morphology. The significantly improved electrocatalytic activity by catalyzing H 2 O 2 of the Cu 2 O@Cu 9 S 5 yolk-shell nanospheres as a sensor has been obtained by comparing with those neat Cu 2 O nanospheres and Cu 9 S 5 hollow nanospheres. This noticeable property is largely due to the synergistic catalysis effect of the contribution of the Cu 2 O and Cu 9 S 5 . Cu 2 O@Cu 9 S 5 yolk-shell nanospheres based non-enzymatic H 2 O 2 sensor displays the relatively wide linear range from 0.1 μM to 3.5 mM with a high sensitivity of 299.74 μA mM −1 cm −2 but low detection limit of 28.83 nM (S/N ≥ 3) for electrochemical detection of H 2 O 2 , which is potentially superior to other similar Cu 2 O-based sensors that has been reported in the literatures. Additionally, this sensor also demonstrates excellent selectivity of H 2 O 2 in the presence of various coactive interferences. This novel Cu 2 O@Cu 9 S 5 yolk-shell nanospheres electrocatalyst provides a broad application prospect for H 2 O 2 sensing.
A novel synthesis strategy for hierarchical polypyrrole nanopillar/silver nanoparticle arrays is designed and its application as an antibacterial surface and nonenzymatic H 2 O 2 sensor is explored. The hierarchical structure is fabricated using a microporous membrane-templated method by multiple steps. Using a polypyrrole nanopillar array as the matrix, silver nanoparticles can be uniformly reduced and stably anchored onto the nanopillar array by a redox reaction in a AgNO 3 solution. The morphology, structural characteristics, conductivity, and reaction mechanisms of the composites are studied in detail. The incorporation of Ag nanoparticles not only significantly enhanced the antibacterial activity of the surface, but also contributed to the excellent ability to detect H 2 O 2 . This work provides a versatile approach to achieve the controlled fabrication of hierarchical metal-conducting polymer composite structures and demonstrates them as promising multifunctional interfaces with antibacterial and sensing activity.