Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
Key Laboratory of Luminescent and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2020 Jan 5;224:117362. doi: 10.1016/j.saa.2019.117362. Epub 2019 Jul 17.
In this work, a novel strategy for perfluorooctane sulfonic acid (PFOS) detection was established by using a ratiometric nanosensor with the combination of fluorescence and second-order scattering (SOS). The practical ratiometric nanosensor was synthesized simply by mixing fluorescent dye ethidium bromide (EB) and nitrogen doped carbon dots (N-CDs) which was synthesized by a one-step hydrothermal method with Victoria Blue B, possessing three emission peaks at 472 nm, 560 nm and 600 nm under a single wavelength excitation of 280 nm, respectively. The EB served as the reference signal label, and the N-CDs, having response to the analytes, acted as the response signal label. To achieve ratiometric detection, the fluorescence emission of the N-CDs was turned off and the SOS emission was turned on with the addition of the target PFOS. To achieve colorimetric detection, with the help of EB, the fluorescence of the system changed from green to orange. Under the optimal conditions, the difference of F/I of the nanosensor had good linearity against the concentrations of PFOS within a linear range of 0-2.0 μM. The limit of detection was as low as 27.8 nM, which was low enough for the detection of PFOS in water samples. The proposed method has been successfully applied to the detection of PFOS with RSD <1.67%. The results show that the as-prepared N-CDs/EB ratiometric nanosensor has potential application for the detection of PFOS in environmental monitoring.
在这项工作中，通过使用荧光和二阶散射（SOS）结合的比率纳米传感器，建立了一种检测全氟辛烷磺酸（PFOS）的新策略。实用的比率纳米传感器是通过混合荧光染料溴化乙锭（EB）和氮掺杂碳点（N-CDs）简单合成的，N-CDs 是通过一步水热法用维多利亚蓝 B 合成的，在 280nm 的单一波长激发下分别具有 472nm、560nm 和 600nm 的三个发射峰。EB 用作参考信号标记，而对分析物有响应的 N-CDs 用作响应信号标记。为了实现比率检测，随着目标 PFOS 的加入，N-CDs 的荧光发射关闭，SOS 发射打开。为了实现比色检测，在 EB 的帮助下，系统的荧光从绿色变为橙色。在最佳条件下，纳米传感器的 F/I 差值对 PFOS 的浓度在 0-2.0µM 的线性范围内具有良好的线性关系。检测限低至 27.8nM，足以用于水样中 PFOS 的检测。该方法已成功应用于 PFOS 的检测，相对标准偏差（RSD）<1.67%。结果表明，所制备的 N-CDs/EB 比率纳米传感器在环境监测中对 PFOS 的检测具有潜在的应用价值。
