School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China.
Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, China.
Mikrochim Acta. 2021 Jul 9;188(8):247. doi: 10.1007/s00604-021-04900-3.
N-doped carbon dots (N-CDs) were fabricated in a simple procedure by hydrothermal treatment of cellobiose and urea. When excited at 235 nm or 327 nm, only one emission peak at around 420 nm has been observed. With the addition of phosalone, the excitation band at 235 nm was efficiently quenched within 1 min, while the excitation band at 327 nm showed little change. Accordingly, the fluorescence of the N-CDs-phosalone mixture showed quenching under 254-nm UV light, while nearly no fluorescence quenching could be observed under 365-nm UV light. This phenomenon provides a novel anti-false-positive mechanism for phosalone identification. Therefore, the label-free ratiometric sensor for rapid, naked-eye, and anti-false-positive detection of phosalone was proposed for the first time based on the intrinsic dual-excitation N-CDs. Under the optimum experimental conditions, the linear ranges of the excitation-based ratiometric assay were 0.084.0 μg/mL and 4.014.0 μg/mL; the limit of detection was 28.5 ng/mL. The as-constructed sensor was applied to detect phosalone residue in actual samples, and results were compared with the standard gas chromatographic (GC) method. The recoveries of the established sensor were between 90.0% and 110.0% with RSD lower than 6.6%, while that for the GC method was between 92.5% and 113.0% with RSD lower than 5.8%. Results reveal that the accuracy (recovery) and precision (RSD) of the as-constructed method are comparable to the standard GC method. In this paper, dual-excitation N-doped carbon dots (N-CDs) were synthesized by a simply one-step hydrothermal method for the first time. The novel dual-excitation ratiometric sensor based on the sole intrinsic N-CDs was constructed for phosalone sensing.
氮掺杂碳点（N-CDs）通过简单的水热处理纤维素和尿素制备。当在 235nm 或 327nm 激发时，只观察到大约 420nm 的一个发射峰。加入涕灭威后，235nm 的激发带在 1 分钟内被有效猝灭，而 327nm 的激发带几乎没有变化。因此，N-CDs-涕灭威混合物在 254nm 紫外光下显示出猝灭，而在 365nm 紫外光下几乎观察不到荧光猝灭。这种现象为涕灭威的识别提供了一种新颖的抗假阳性机制。因此，首次基于内源性双激发 N-CDs 提出了用于快速、肉眼、抗假阳性检测涕灭威的无标记比率传感器。在最佳实验条件下，基于激发的比率测定法的线性范围为 0.084.0μg/mL 和 4.014.0μg/mL；检测限为 28.5ng/mL。所构建的传感器用于检测实际样品中的涕灭威残留，结果与标准气相色谱（GC）法进行比较。所建立的传感器的回收率在 90.0%110.0%之间，相对标准偏差（RSD）低于 6.6%，而 GC 法的回收率在 92.5%113.0%之间，RSD 低于 5.8%。结果表明，所构建方法的准确性（回收率）和精密度（RSD）与标准 GC 法相当。本文首次通过简单的一步水热法合成了双激发氮掺杂碳点（N-CDs）。基于唯一的内源性 N-CDs 构建了新型双激发比率传感器，用于涕灭威传感。
