The development of electrocatalysts that show multifunctionality towards efficient sensing and energy applications are of great significance. Herein, we report a rational design of photochemical deposition of Ag nanoparticles (Ag NPs) on ZIF-67-decorated carbon nanotube (Ag NPs/ZIF-67 @CNT) hybrid, which exhibits dual-functional capabilities for both effective enzymeless glucose detection and electrocatalytic water oxidation . The distribution of Ag NPs on the ZIF-67-functionalized CNT can be optimized by adjusting the concentration of Ag + aqueous solution during the light illumination process. The optimized Ag NPs/ZIF-67 @CNT composite showed superior glucose-sensing capability with a low determination limit of 0.46 μM (S/N = 3), high sensitivity of 469.4 μA·mM −1 ·cm −2 , wide linearity detection range (0.010–7.0 mM) and short response time (less than 5 s). Also, the Ag NPs/ZIF-67 @CNT composite acting as potential electrocatalyst possessed an overpotential of 286 mV with a Tafel-slope of 80.75 mV dec −1 at 10 mA·cm −2 for high durability water-oxidation reaction. This work provided a feasible way to prepare Ag NPs decorated ZIF-67/CNT with modulated bifunctional catalytic performances via photochemical reduction strategy, which can also provide effective guidance for designing other multifunctional electrocatalysts .
Tremendous demands for highly sensitive and selective nonenzymatic electrochemical biosensors have motivated intensive research on advanced electrode materials with high electrocatalytic activity. Herein, the 3D-networked CuO@carbon nanowalls/diamond (C/D) architecture is rationally designed, and it demonstrates wide linear range (0.5 × 10 −6 –4 × 10 −3 m ), high sensitivity (1650 µA cm −2 m m −1 ), and low detection limit (0.5 × 10 −6 m ), together with high selectivity, great long-term stability, and good reproducibility in glucose determination. The outstanding performance of the CuO@C/D electrode can be ascribed to the synergistic effect coming from high-electrocatalytic-activity CuO nanoparticles and 3D-networked conductive C/D film. The C/D film is composed of carbon nanowalls and diamond nanoplatelets; and owing to the large surface area, accessible open surfaces, and high electrical conduction, it works as an excellent transducer, greatly accelerating the mass- and charge-transport kinetics of electrocatalytic reaction on the CuO biorecognition element. Besides, the vertical aligned diamond nanoplatelet scaffolds could improve structural and mechanical stability of the designed electrode in long-term performance. The excellent CuO@C/D electrode promises potential application in practical glucose detection, and the strategy proposed here can also be extended to construct other biorecognition elements on the 3D-networked conductive C/D transducer for various high-performance nonenzymatic electrochemical biosensors.