Department of Chemistry, Yasouj University, Yasouj 75918-74831, Iran.
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada.
Biosensors (Basel). 2020 Mar 11;10(3):23. doi: 10.3390/bios10030023.
In this paper, an electrochemical technique is introduced for the determination of streptomycin (STR) in the presence of oxytetracycline (OTC) in milk samples. A novel bifunctional modified screen-printed electrode (SPE) modified with oracet blue, silver nanoparticles, and graphene oxide (OB/SNPs/GO/SPE) was fabricated. The modified electrode plays a catalyzer role for electrooxidation of STR at pH = 7.0 and reveals a facile a separation between the oxidation peaks of STR and OTC. Calculation of kinetic parameters such as the electron transfer coefficient α and the heterogeneous rate constant ´ of STR at the OB/SNPs/GO/SPE as 8.1 ± 0.07 cm s and 0.32 have been obtained based on the theoretical model of Andrieux and Saveant. A differential pulse voltammetric measurement demonstrates two linear dynamic ranges, 0.4 to 240.0 nM and 240.0 to 720.0 nM and a detection limit of 0.17 nM for STR. The sensitivities of the OB/SNPs/GO/SPE towards the oxidation of STR in the absence and presence of OTC were 2.625 × 10 and 2.633 × 10 µA/µM, respectively.
本文介绍了一种在牛奶样品中存在土霉素的情况下测定链霉素（STR）的电化学技术。制备了一种新型的双功能修饰丝网印刷电极（SPE），该电极修饰有邻甲氧基偶氮蓝、银纳米粒子和氧化石墨烯（OB/SNPs/GO/SPE）。在 pH = 7.0 下，修饰电极对 STR 的电氧化起到了催化剂的作用，并显示出 STR 和 OTC 的氧化峰之间易于分离。根据 Andrieux 和 Saveant 的理论模型，计算了 STR 在 OB/SNPs/GO/SPE 上的动力学参数，如电子转移系数α和非均相速率常数´，分别为 8.1 ± 0.07 cm s 和 0.32。差分脉冲伏安法测量显示，STR 的两个线性动态范围为 0.4 至 240.0 nM 和 240.0 至 720.0 nM，检测限为 0.17 nM。OB/SNPs/GO/SPE 对 STR 氧化的灵敏度在没有和存在 OTC 的情况下分别为 2.625 × 10 和 2.633 × 10 µA/µM。
