National Institute for Research and Development of Isotopic and Molecular Technologies, Donat Street, No. 67-103, 400293 Cluj-Napoca, Romania.
Sensors (Basel). 2022 May 10;22(10):3606. doi: 10.3390/s22103606.
In this study, a graphene sample (EGr) was synthesized by electrochemical exfoliation of graphite rods in electrolyte solution containing 0.1 M ammonia and 0.1 M ammonium thiocyanate. The morphology of the powder deposited onto a solid substrate was investigated by the scanning electron microscopy (SEM) technique. The SEM micrographs evidenced large and smooth areas corresponding to the basal plane of graphene as well as white lines (edges) where graphene layers fold-up. The high porosity of the material brings a major advantage, such as the increase of the active area of the modified electrode (EGr/GC) in comparison with that of bare glassy carbon (GC). The graphene modified electrode was successfully tested for L-tyrosine detection and the results were compared with those of bare GC. For EGr/GC, the oxidation peak of L-tyrosine had high intensity (1.69 × 10 A) and appeared at lower potential (+0.64 V) comparing with that of bare GC (+0.84 V). In addition, the graphene-modified electrode had a considerably larger sensitivity (0.0124 A/M) and lower detection limit (1.81 × 10 M), proving the advantages of employing graphene in electrochemical sensing.
在这项研究中，通过在含有 0.1 M 氨和 0.1 M 硫氰酸铵的电解质溶液中电化学剥离石墨棒来合成石墨烯样品（EGr）。通过扫描电子显微镜（SEM）技术研究了沉积在固体基底上的粉末的形态。SEM 显微照片表明，存在对应于石墨烯基面的大而光滑的区域以及石墨烯层折叠的白线（边缘）。该材料的高孔隙率带来了一个主要优势，例如与裸玻碳（GC）相比，修饰电极（EGr/GC）的活性面积增加。成功地测试了石墨烯修饰电极用于 L-酪氨酸的检测，并将结果与裸 GC 的结果进行了比较。对于 EGr/GC，L-酪氨酸的氧化峰具有高强度（1.69×10 A），并且出现在比裸 GC 更低的电位（+0.64 V）处（+0.84 V）。此外，石墨烯修饰电极具有相当大的灵敏度（0.0124 A/M）和更低的检测限（1.81×10 M），证明了在电化学传感中使用石墨烯的优势。
