Abstract This paper describes the modification of a modified carbon paste electrode (CPE) using nanoparticles of praseodymium erbium tungstate (Pr:Er). The modified electrode was used for the sensitive voltammetric detection of an anticancer drug (5-fluorouracil (5-FU)) using. The modified-CPE was evaluated using cyclic voltammetry (CV), square wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) and the resulting data showed the irreversible 5-fluorouracil oxidation peak around 1.0 V vs. Ag/AgCl. Some key parameters such as pH, the amount of the modifier, potential amplitude, step potential and frequency were studied and optimized. The square wave voltammetry (SWV) analytical calibration curve was linear in the range of 0.01–50 μM, with a detection limit of 0.98 nM analyses. The electron transfer coefficient (α) was also determined to be 0.76. The analyte concentration was also determined in pharmaceutical formulations and recovery percentages were found to be in the range of 96–102%. The sensor had good reproducibility and repeatability with acceptable RSD values of 3.6%, and 1.02% and a rather long-term stability of around one month. The as-synthesized nanoparticles were also characterized using FESEM, TEM, FTIR and XRD techniques.

中文翻译：

---

钨酸镨复合物改性的5-氟尿嘧啶基敏感碳糊电极

摘要 本文描述了使用钨酸镨 (Pr:Er) 纳米粒子对改性碳糊电极 (CPE) 的改性。修饰电极用于抗癌药物（5-氟尿嘧啶（5-FU））的灵敏伏安检测。使用循环伏安法 (CV)、方波伏安法 (SWV) 和电化学阻抗谱 (EIS) 对改性 CPE 进行评估，所得数据显示不可逆的 5-氟尿嘧啶氧化峰在 1.0 V 与 Ag/AgCl 附近。对pH值、改性剂用量、电位幅度、阶跃电位和频率等关键参数进行了研究和优化。方波伏安法 (SWV) 分析校准曲线在 0.01–50 μM 范围内呈线性，分析检测限为 0.98 nM。电子转移系数 (α) 也被确定为 0.76。还测定了药物制剂中的分析物浓度，发现回收率在 96-102% 的范围内。该传感器具有良好的重现性和重复性，可接受的 RSD 值为 3.6% 和 1.02%，并且具有约 1 个月的长期稳定性。还使用 FESEM、TEM、FTIR 和 XRD 技术对合成的纳米粒子进行了表征。