Analytical Chemistry Department, Kazan Federal University, Kremleyevskaya 18, 420008 Kazan, Russia.
Sensors (Basel). 2022 Apr 22;22(9):3224. doi: 10.3390/s22093224.
Indigo carmine is a widely used colorant in the food and pharmaceutical industry a high concentration of which can lead to a wide range of negative effects on human health. Therefore, colorant contents have to be strictly controlled. SeO-nanoparticle-modified glassy carbon electrodes (GCE) have been developed as a voltammetric sensor for indigo carmine. Various types and concentrations of surfactants have been used as reagents for the stabilization of SeO nanoparticle dispersions and as electrode surface co-modifiers. An amount of 1.0 mM cationic cetylpyridinium bromide (CPB) provides the best response of the indigo carmine on the modified electrode. The electrodes were characterized by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy (EIS). SeO nanoparticle-CPB-modified electrodes show 4.2-fold higher electroactive area vs. GCE as well as a dramatic 5043-fold decrease in the electron transfer resistance indicating effectivity of the modifier developed. The surface-controlled electrooxidation of indigo carmine proceeds irreversibly (α = 0.46) with the participation of two electrons and two protons. A linear dynamic range of 0.025-1.0 and 1.0-10 µM of indigo carmine were obtained with the detection and quantification limits of 4.3 and 14.3 nM, respectively. The practical applicability of the sensor was successfully shown on the pharmaceutical dosage forms.
靛蓝胭脂红是食品和制药工业中广泛使用的着色剂，其高浓度会对人类健康产生广泛的负面影响。因此，必须严格控制着色剂的含量。硒纳米粒子修饰的玻碳电极（GCE）已被开发为用于靛蓝胭脂红的伏安传感器。各种类型和浓度的表面活性剂已被用作稳定硒纳米粒子分散体的试剂和电极表面共修饰剂。1.0 mM 的阳离子十六烷基溴化吡啶（CPB）提供了修饰电极上靛蓝胭脂红的最佳响应。通过循环伏安法、计时安培法和电化学阻抗谱（EIS）对电极进行了表征。与 GCE 相比，SeO 纳米粒子-CPB 修饰电极的电活性面积高 4.2 倍，电子转移电阻显著降低了 5043 倍，表明所开发的修饰剂具有有效性。靛蓝胭脂红的表面控制电氧化不可逆（α=0.46），涉及两个电子和两个质子。靛蓝胭脂红的线性动态范围为 0.025-1.0 和 1.0-10 μM，检测限和定量限分别为 4.3 和 14.3 nM。该传感器在药物制剂中的实际应用得到了成功展示。
