Highly selective H_2O_2 sensor based on 1-D nanoporous Pt@C hybrids with core-shell structure

摘要

A strategy of sacrificial template was put forward to prepare porous Pt nanowires core with carbon shell (Pt PNW@C) usingTe nanowires as template. These Pt PNW@C hybrids show a highly sensitive response to H_2O_2 oxidation recorded by chronoamperometry at 0.2 V vs. the saturated calomel electrode (SCE). Under optimal conditions, this H_2O_2 transducer displays a linear range of 0.01 -1.2 μM with a sensitive of 6.28μAμM~(-1) cm~(-2) (r=0.9997), and a detection limit of 0.002 μM (signaloise=3). Moreover, the carbon layer on Pt PNW@C hybrids can greatly enhance the selectivity in H_2O_2 detection in the presence of the common interfering species, such as lactic acid (LA), uric acid (UA), creatinine and glucose, at a positive potential by compared with porous Pt nanowires (Pt PNWs). A glucose biosensor was constructed using this sensitive and selective H_2O_2 transducer combined with glucose oxidase. A calibration curve of glucose concentration can be obtained by measureing enzymatically generated H_2O_2, which shows a linear range from 0.5 to 20 μM with a sensitivity of 0.35 μA μM~(-1) cm~(-2) and a detection limit of 0.1 μM.