作为一种化疗药物，5-氟尿嘧啶（5-FU）已用于治疗结肠癌数十年。人体内过量的5-FU会导致显着的不良反应，包括严重腹泻、感染、口腔溃疡、皮肤脱皮、皮肤炎症和溃疡，这些都是重要且相对常见的消化道副作用。此外，5-FU是尿嘧啶的类似物，也与嘧啶有相似之处。因此，将它们分开并不容易。这项研究提出了一种能够检测微量药物的传感器。藻酸盐衍生的碳点 (CD) 是通过独特的光学特性合成的，该碳点遵循 5-FU 传感的开关荧光机制。将铜 (Cu(I)) 引入 CD 会通过电子转移导致荧光猝灭。然而，当 5-FU 作为氧化剂添加到系统中时，CD 表面会发生氧化还原反应，从而导致荧光恢复，因为 Cu(I) 变为 Cu(II)。实验结果显示，在 1.00-45.00 nM 的浓度范围内，存在很强的线性相关性 (R2 = 0.99)，并进行如下线性回归，并显示相对标准偏差 (RSD%) 和检测限分别为 2.57% 和 1.00 nM 。这些结果验证了该方法即使在低浓度 5-FU 以及存在其他药物和干扰物质的情况下也具有出色的检测能力。此外，血清样品中 5-FU 的回收率（从 100.46% 到 113.7%，RSD 等于 1.89-3.63）表明 5-FU 测定中不存在基质干扰。总之，这种开发具有成本效益且灵敏的传感器的新颖方法在医疗保健和相关领域的未来应用中具有巨大的潜力。© 2024 国际生物化学和分子生物学联合会，Inc.

As a chemotherapy drug, 5-fluorouracil (5-FU) has been used for colon cancer for decades. Excessive levels of 5-FU in the human body can lead to notable adverse effects, including severe diarrhea, infection, mouth sores, skin peeling, skin inflammation, and ulcers, which are important and relatively common digestive side effects. In addition, 5-FU is an analog of uracil and also has similarities to pyrimidines. Therefore, it is not easy to separate them. This research presented a sensor capable of detecting drugs in minimal amounts. An alginate-derived carbon dot (CD) was synthesized by unique optical properties that obey an on-off fluorescence mechanism for 5-FU sensing. Introducing copper (Cu(I)) to CDs results in fluorescence quenching through electron transfer. However, when 5-FU is added to the system as an oxidizing agent, a redox reaction occurs on the surface of the CDs, which leads to the restoration of fluorescence as Cu(I) is altered to Cu(II). Experimental results showed a strong linear correlation (R2 = 0.99) in the concentration range of 1.00-45.00 nM, with the following linear regression, and revealed the relative standard deviation (RSD%) and detection limit of 2.57%, and 1.00 nM, respectively. These results validated the excellent detection capability of the proposed method even at low concentrations of 5-FU and in the presence of other drugs and interfering substances. Also, the recovery of 5-FU (varies from 100.46% to 113.7%, with RSD equal to 1.89-3.63) in serum samples indicates the absence of matrix interference in the determination of 5-FU. In summary, this novel approach to developing a cost-effective and sensitive sensor holds great potential for future applications in healthcare and related fields.© 2024 International Union of Biochemistry and Molecular Biology, Inc.