Wang Huiwen, Wang Caiqin, Yang Beibei, Zhai Chunyang, Bin Duan, Zhang Ke, Yang Ping, Du Yukou
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P R China.
Analyst. 2015 Feb 21;140(4):1291-7. doi: 10.1039/c4an01924e.
We describe a simple electrochemical preparation method of a novel three dimensional (3D) graphene material, porous flower-like reduced graphene oxide (f-RGO) nanosheets, which was explored as the support for Cu particles on a glassy carbon electrode (Cu/f-RGO/GCE) for detecting nitrite. In morphology studies, scanning electron microscopy (SEM) demonstrates the 3D porous structure of f-RGO enlarges the surface area of the electrode and promotes more Cu particles depositing on the surface of f-RGO with homogeneous dispersion. In cyclic voltammetry (CV), a well-defined voltammetric peak along with the remarkable reduction current indicates excellent electrocatalytic activity of the Cu/f-RGO/GCE for NaNO2 reduction compared with other corresponding electrodes. The effects of pH value and detection potential on the current responses of Cu/f-RGO/GCE towards nitrite were optimized to obtain the maximal sensitivity. In the optimal experimental conditions, Cu/f-RGO/GCE displays the wide detection range from 0.15 μM to 10,500 μM and the low limit of detection of 0.06 μM (S/N = 3) with fast response time 2 s for detecting NaNO2 through an amperometric method. Furthermore, the presence of K(+), Na(+), Cl(-), NH4(+), NO3(-), SO4(2-) and ascorbic acid show a negligible effect on the current response of nitrite determination suggesting Cu/f-RGO/GCE have the high selectivity for detecting nitrite even in the presence of high concentration of interferents. Moreover, the real sample determination experiment indicated practical feasibility of the obtained sensor. The prepared sensor for determination of NaNO2 exhibited wide liner range, low detection limit, good reproducibility, nice stability and remarkable anti-interference ability. In this paper, not only did the Cu/f-RGO/GCE show high performance for determination of nitrite, but also it was simple to prepare, user-friendly and cost-effective.
我们描述了一种新型三维（3D）石墨烯材料——多孔花状还原氧化石墨烯（f-RGO）纳米片的简单电化学制备方法，该材料被用作玻碳电极（Cu/f-RGO/GCE）上铜颗粒的载体用于检测亚硝酸盐。在形态学研究中，扫描电子显微镜（SEM）表明f-RGO的三维多孔结构扩大了电极的表面积，并促进更多铜颗粒均匀分散地沉积在f-RGO表面。在循环伏安法（CV）中，明确的伏安峰以及显著的还原电流表明，与其他相应电极相比，Cu/f-RGO/GCE对NaNO2还原具有优异的电催化活性。优化了pH值和检测电位对Cu/f-RGO/GCE对亚硝酸盐电流响应的影响，以获得最大灵敏度。在最佳实验条件下，Cu/f-RGO/GCE通过安培法检测NaNO2时，显示出0.15 μM至10,500 μM的宽检测范围和0.06 μM（S/N = 3）的低检测限，响应时间快至2 s。此外，K(+)、Na(+)、Cl(-)、NH4(+)、NO3(-)、SO4(2-)和抗坏血酸的存在对亚硝酸盐测定的电流响应影响可忽略不计，这表明即使在高浓度干扰物存在的情况下，Cu/f-RGO/GCE对检测亚硝酸盐仍具有高选择性。此外，实际样品测定实验表明所制备传感器具有实际可行性。所制备的用于测定NaNO2的传感器具有宽线性范围、低检测限、良好的重现性、出色的稳定性和显著的抗干扰能力。本文中，Cu/f-RGO/GCE不仅在测定亚硝酸盐方面表现出高性能，而且制备简单、用户友好且具有成本效益。
