Zhou Ying, Ding Min, Lyu Wenjing, Zhen Qianna, Chen Hong, Jiang Mengdan, Ding Yanxiang, Zhang Xiaoqing
Key Laboratory of Clinical Laboratory Diagnostics (Ministry of Education of China), School of Laboratory Medicine, Chongqing Medical University, Chongqing, 400016, PR China.
Department of Endocrinology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, PR China.
Anal Chim Acta. 2021 Jan 15;1142:56-64. doi: 10.1016/j.aca.2020.10.055. Epub 2020 Oct 30.
Indole is a major metabolite of tryptophan, which plays an important role in the intestinal microecological balance and human physiological activities. The determination of indole becomes important for its researches. So, it is urgent to establish a sensitive and cost-effective method for indole detection. Herein, a sensitive electrochemical method was constructed to determine the concentration of indole using screen-printed carbon electrode (SPCE) with the signal amplification strategy by gold/iron-oxide composite nanoparticles (Au/FeO). Au/FeO nanoparticles were successfully synthesized under the irradiation by high-energy electron beams. 4-aminothiophenol (4-ATP) was connected to Au/FeO via Au-S bond. And then NaNO reacted with 4-ATP to form the azo bond, which could form the final product of Au/FeO@ATP-azo-indole by the coupling reaction. Thus, the concentration of indole was detected by the electrochemical signal produced by Au/FeO@ATP-azo-indole indirectly. The detection sensitivity was greatly improved by the large specific surface area provided by Au/FeO after the modification. The linear range of indole was from 0.50 to 120.00 μg L and the limit of detection (LOD) was as low as 0.10 μg L (S/N = 3). Furthermore, the developed method exhibited acceptable intra-day and inter-day precisions with the coefficient of variations (CV) less than 4.9% and 8.2%, respectively. And the recoveries were from 97.2% to 105.4%. An innovative, sensitive, cost-effective method was established for indole determination in human plasma matrix in this manuscript, which provides a promising way for indole detection in conventional laboratories.
吲哚是色氨酸的主要代谢产物，在肠道微生态平衡和人体生理活动中发挥着重要作用。吲哚的测定对于其相关研究具有重要意义。因此，迫切需要建立一种灵敏且经济高效的吲哚检测方法。在此，构建了一种灵敏的电化学方法，使用丝网印刷碳电极（SPCE），通过金/铁氧化物复合纳米粒子（Au/FeO）的信号放大策略来测定吲哚浓度。Au/FeO纳米粒子在高能电子束照射下成功合成。4-氨基硫酚（4-ATP）通过Au-S键连接到Au/FeO上。然后NaNO与4-ATP反应形成偶氮键，通过偶联反应可形成Au/FeO@ATP-偶氮-吲哚的最终产物。因此，通过Au/FeO@ATP-偶氮-吲哚间接产生的电化学信号来检测吲哚浓度。修饰后Au/FeO提供的大比表面积大大提高了检测灵敏度。吲哚的线性范围为0.50至120.00 μg/L，检测限（LOD）低至0.10 μg/L（S/N = 3）。此外，所开发的方法在日内和日间精密度方面表现良好，变异系数（CV）分别小于4.9%和8.2%。回收率为97.2%至105.4%。本论文建立了一种创新、灵敏、经济高效的人血浆基质中吲哚测定方法，为常规实验室中的吲哚检测提供了一条有前景的途径。
