AbstractThe dopant bumetanide (BMT) was banned by the World Anti-Doping Agency. The authors describe a voltammetric sensor for the determination of BMT in urine that is based on the use of a glassy carbon electrode modified with reduced graphene oxide (GCE/rGO). The GCE/rGO was prepared by electrodeposition from a solution of GO. The oxidation of BMT occurs best at +0.75 V in the GCE/rGO with an approximately 13-fold gain in the anode current compared to a conventional GCE. The oxidation mechanism was investigated by means of electrolysis, while the analysis of the products was carried out via the LC–MS/MS. Under optimized conditions (scan rate 100 mV s−1; pH 4.0; accumulation time 25 s) and by using linear sweep adsorptive stripping voltammetry, the response covers the 0.26 to 50 μmol L−1 BMT concentration range. The detection limit is 75 nmol L−1. The sensor was successfully applied and validated by LC–MS/MS analysis of spiked urine sample. Graphical abstractSchematic of a glassy carbon electrode modified with reduced graphene oxide by electrodeposition using a solution of graphene oxide. The modified electrode showed an improvement in the electron transfer kinetics and a large increase in the analytical signal.

中文翻译：

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一种用还原氧化石墨烯修饰的玻碳电极，可灵敏测定尿液中布美他尼的浓度，达到兴奋剂分析所需的水平

摘要 世界反兴奋剂机构禁止使用掺杂剂布美他尼（BMT）。作者描述了一种用于测定尿液中 BMT 的伏安传感器，该传感器基于使用经还原氧化石墨烯 (GCE/rGO) 修饰的玻璃碳电极。GCE/rGO 由 GO 溶液通过电沉积制备。BMT 的氧化在 GCE/rGO 中最好发生在 +0.75 V，与传统 GCE 相比，阳极电流增加了大约 13 倍。通过电解研究氧化机理，而通过 LC-MS/MS 对产物进行分析。在优化条件下（扫描速率 100 mV s-1；pH 4.0；累积时间 25 s）并通过使用线性扫描吸附溶出伏安法，响应涵盖 0.26 至 50 μmol L-1 BMT 浓度范围。检测限为 75 nmol L-1。该传感器已成功应用并通过加标尿样的 LC-MS/MS 分析得到验证。图形摘要使用氧化石墨烯溶液通过电沉积用还原氧化石墨烯修饰的玻璃碳电极示意图。修饰电极显示出电子转移动力学的改进和分析信号的大幅增加。