Department of Applied Chemistry, Mashhad Branch, Islamic Azad University, Mashhad, Iran.
Department of Applied Chemistry, Quchan Branch, Islamic Azad University, Quchan, Iran.
Nanotechnology. 2022 Feb 15;33(19). doi: 10.1088/1361-6528/ac45c6.
A highly sensitive and selective modified electrode was successfully developed for the monitoring of nicotinamide adenine dinucleotide (NADH) in the presence of folic acid. In this regard, a carbon paste electrode (CPE) was functionalized by the nitrogen-doped carbon quantum dots/tin oxide (N-CQDs/SnO) nanocomposite and 1-butyl-2,3-dimethyl imidazolium hexafluorophosphate ([CDMIM][PF]) ionic liquid (IL). The structure and surface morphology of the nanocomposite were characterized by various methods, including field emission scanning electron microscopy, energy dispersive spectroscopy (EDS), high-resolution transmission electron microscopy (HR-TEM), and x-ray diffraction (XRD). The modified electrode displayed powerful and long-lasting electron mediating activity, with well-separated NADH and folic acid oxidation peaks. The sensing response of the developed [CDMIM][PF]/N-CQDs/SnO/CPE platform was evaluated by determining NADH via the voltammetric technique under the optimized operating conditions. The current peaks of the square wave voltammograms of NADH and folic acid increased linearly with enhancing its concentrations within the ranges of 0.003-275M NADH and 0.4-380M folic acid. The detection limits for NADH and folic acid were obtained at 0.8 nM and 0.1M, respectively. Interference species such as glucose, urea, tryptophan, glycine, methionine, and vitamin Bhad no influence on the ability of the fabricated modified electrode to detect the target species. The low detection limit, high sensitivity, excellent selectivity, superior stability, and cost-effectiveness made it suitable for the quantification of NADH in the real biological samples with the recovery percent values in the range of 97.5%-103%.
一种高灵敏度和选择性的修饰电极被成功开发用于在叶酸存在下监测烟酰胺腺嘌呤二核苷酸（NADH）。在这方面，通过氮掺杂碳量子点/氧化锡（N-CQDs/SnO）纳米复合材料和 1-丁基-2,3-二甲基咪唑六氟磷酸盐（[CDMIM][PF]）离子液体（IL）对碳糊电极（CPE）进行功能化。纳米复合材料的结构和表面形态通过各种方法进行了表征，包括场发射扫描电子显微镜、能量色散光谱（EDS）、高分辨率透射电子显微镜（HR-TEM）和 X 射线衍射（XRD）。修饰电极显示出强大而持久的电子介导活性，具有分离良好的 NADH 和叶酸氧化峰。通过在优化的操作条件下通过伏安技术测定 NADH 来评估所开发的 [CDMIM][PF]/N-CQDs/SnO/CPE 平台的传感响应。在 NADH 和叶酸的方波伏安图中，电流峰随着其浓度在 0.003-275M NADH 和 0.4-380M 叶酸范围内的增加而线性增加。NADH 和叶酸的检测限分别为 0.8 nM 和 0.1M。干扰物质，如葡萄糖、尿素、色氨酸、甘氨酸、蛋氨酸和维生素 B，对制备的修饰电极检测目标物质的能力没有影响。低检测限、高灵敏度、优异的选择性、卓越的稳定性和成本效益使其适合于实际生物样品中 NADH 的定量，回收率值在 97.5%-103%的范围内。
