Department of Chemical Sciences, University of Johannesburg, Doornfontein, 2028, South Africa.
Department of Chemical Sciences, University of Johannesburg, Doornfontein, 2028, South Africa; Centre for Nanomaterials Science Research, University of Johannesburg, South Africa.
Chemosphere. 2022 Sep;303(Pt 1):134961. doi: 10.1016/j.chemosphere.2022.134961. Epub 2022 May 13.
Development of electrochemical sensors for important drugs such nicotine (an addictive drug) is important for the society. This study reports the electrochemical detection of nicotine at a carbon nanofiber/poly (amidoamine) dendrimer modified glassy carbon electrode. The carbon nanofiber (CNF) modified GCE was prepared by drop-coating followed by the electrodeposition of generation 4 poly (amidoamine) succinamic acid dendrimer (PAMAM) to form the sensor - CNF-PAMAM GCE. Characterization of prepared materials and modified electrodes was carried out using Fourier transmission infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). The CNF-PAMAM composite was confirmed by microscopy. A marked reduction in charge transfer resistance and increase in current of the CNF-PAMAM GCE in comparison to the bare electrode showed a synergic improvement electrochemical response because of the CNF-PAMAM nanocomposite. The CNF-PAMAM demonstrated an enhanced performance in the oxidation of nicotine in comparison to the bare GCE by shifting the anodic potential E of nicotine from 0.9 V to 0.8 V. The electrochemical sensor achieved a detection limit (LOD) of 0.02637 μM in the concentration range of 0.4815-15.41 μM of nicotine in 0.1 M PBS at pH 7.5. The sensor ability to determine nicotine in real samples was assessed in cigarettes obtaining recovery percentages of 88.00 and 97.42%. The sensor demonstrated selectivity toward nicotine in the presence of interferences. Finally, the method was validated by ultraviolet-visible spectroscopy analysis.
电化学传感器的发展对于社会来说非常重要，特别是对于尼古丁（一种成瘾药物）等重要药物的检测。本研究报告了在碳纳米纤维/聚（酰胺-胺）树枝状大分子修饰玻碳电极上电化学检测尼古丁。通过滴涂法制备碳纳米纤维（CNF）修饰的 GCE，然后进行第 4 代聚（酰胺-胺）琥珀酸树枝状大分子（PAMAM）的电沉积，形成传感器 - CNF-PAMAM GCE。采用傅里叶变换红外光谱、场发射扫描电子显微镜、透射电子显微镜、拉曼光谱、循环伏安法、电化学阻抗谱（EIS）和差分脉冲伏安法（DPV）对制备材料和修饰电极进行了表征。通过显微镜观察到 CNF-PAMAM 复合材料的形成。与裸电极相比，CNF-PAMAM GCE 的电荷转移电阻显著降低，电流增加，表明由于 CNF-PAMAM 纳米复合材料的协同作用，电化学响应得到了改善。与裸 GCE 相比，CNF-PAMAM 对尼古丁的氧化表现出增强的性能，使尼古丁的阳极电位 E 从 0.9 V 移至 0.8 V。电化学传感器在 0.1 M PBS（pH 7.5）中尼古丁浓度范围为 0.4815-15.41 μM 时，检测限（LOD）达到 0.02637 μM。该传感器在香烟等实际样品中检测尼古丁的能力进行了评估，回收率分别为 88.00%和 97.42%。该传感器在存在干扰物质的情况下对尼古丁表现出选择性。最后，通过紫外可见光谱分析对该方法进行了验证。
