| Graphene is a novel two-dimensional (2D) carbon nanomaterial composedof a layer of carbon atoms. The graphene sheets in graphene foam (GF) wereseamlessly interconnected into a3D flexible network. It has high specific surfacearea, porosity and outstanding electrical properties. The GF material not only hasexcellent mechanical, optical and chemical properties, but also has excellentelectrical properties. It expands graphene’application space of physics andchemistry, making it the current hot field of material science.By using the chemical vapor deposition (CVD), the three dimensional (3D)porous high conductivity of graphene foam was fabricated with nickel foam as atemplate and catalyst, methane as a carbon source and hydrogen and argon forprotection. GF was characterized by scanning electron microscopy (SEM),Raman spectroscopy and X-ray diffraction. The GF was transferred onto ITOcoated glass, acting as an electrode to detect uric acid and ascorbic acid byelectrochemical methods to study the electrical performance of thiselectrochemical biosensor.SEM observed that graphene foam had a3D macroporous network structurewith an average pore diameter. XRD analysis found that the product was purewithout impurities, Raman spectra showed that the product was a few layersgraphene with high quality and defect free. Electrochemical results showed thatthe GF exhibited high selectivity, stability, reproducibility, sensitivity and lowdection limit for the detection of uric acid. When the concentration of uric acidwas in the range of25nM~1μM, its sensitivity for uric acid was9.44mA·mM-1;when the concentration of uric acid was in the range of1μM~60μM, thesensitivity is1.85mAmM-1and the detection limit was3nM. This demonstratedthe free-standing GF which was synthesized by chemical vapor depositionprovided a promising platform as a3D biosensing material. |
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