Department of Chemistry and Institute of BioPhysio Sensor Technology, Pusan National University, Busan 609-735, South Korea.
Department of Chemistry and Institute of BioPhysio Sensor Technology, Pusan National University, Busan 609-735, South Korea.
Anal Chim Acta. 2015 Sep 10;892:77-84. doi: 10.1016/j.aca.2015.08.037. Epub 2015 Aug 28.
The rapid simultaneous determination of cadmium, lead, copper, and mercury ions is performed by employing a disposable sensor modified with graphene oxide (GO) doped diaminoterthiophene (GO/DTT) for chronocoulometry (CC). The performances of CC with and without pre-deposition in two opposite potential step directions were compared with square wave anodic stripping voltammetry (SWASV) under various conditions. The surface of the GO/DTT modified screen print carbon electrode (SPCE) was characterized by SEM, EDXS, and electrochemical impedance spectroscopy (EIS). Experimental variables that affect the response signal such as the pH, deposition time, type of supporting electrolyte, concentration of DTT, content ratio of GO to DTT, and Nafion content were optimized. Interference effects due to other heavy metal ions were also investigated. The dynamic ranges of SWASV and CC were between 1 ng mL(-1) and 2.5 μg mL(-1) and between 1 ng mL(-1) and 10 μg mL(-1), respectively. The detection limits for Cd(2+), Pb(2+), Cu(2+), Hg(2+) ions were 1.9 ± 0.4 ng mL(-1), 2.8 ± 0.6 ng mL(-1), 0.8 ± 0.2 ng mL(-1), and 2.6 ± 0.9 ng mL(-1) for the CC stripping method; 2.6 ± 0.2 ng mL(-1), 0.5 ± 0.1 ng mL(-1), 1.8 ± 0.3 ng mL(-1), and 3.2 ± 0.3 ng mL(-1) for the CC deposition method; and 7.1 ± 0.9, 1.9 ± 0.3, 0.4 ± 0.1, and 0.7 ± 0.1 ng mL(-1) for SWASV. The reliability of the method for point-of-analysis was evaluated by analyzing a urine standard reference material and some water samples.
采用氧化石墨烯（GO）掺杂二氨基三噻吩（GO/DTT）修饰的一次性传感器，通过计时库仑法（CC）实现对镉、铅、铜和汞离子的快速同步测定。在不同条件下，比较了在两个相反电位阶跃方向进行预沉积前后 CC 与方波阳极溶出伏安法（SWASV）的性能。用 SEM、EDXS 和电化学阻抗谱（EIS）对 GO/DTT 修饰的丝网印刷碳电极（SPCE）的表面进行了表征。优化了影响响应信号的实验变量，如 pH 值、沉积时间、支持电解质类型、DTT 浓度、GO 与 DTT 的含量比以及 Nafion 含量。还研究了其他重金属离子的干扰效应。SWASV 和 CC 的动态范围分别为 1 ng mL(-1)至 2.5 μg mL(-1)和 1 ng mL(-1)至 10 μg mL(-1)。对于 CC 剥离法，Cd(2+)、Pb(2+)、Cu(2+)、Hg(2+)离子的检出限分别为 1.9 ± 0.4 ng mL(-1)、2.8 ± 0.6 ng mL(-1)、0.8 ± 0.2 ng mL(-1)和 2.6 ± 0.9 ng mL(-1)；对于 CC 沉积法，分别为 2.6 ± 0.2 ng mL(-1)、0.5 ± 0.1 ng mL(-1)、1.8 ± 0.3 ng mL(-1)和 3.2 ± 0.3 ng mL(-1)；对于 SWASV，分别为 7.1 ± 0.9、1.9 ± 0.3、0.4 ± 0.1 和 0.7 ± 0.1 ng mL(-1)。通过分析尿液标准参考物质和一些水样，评估了该方法在现场分析中的可靠性。
