Abstract：
Using lignin as a raw material to prepare fluorescent nanomaterials represents a significant pathway toward the high-value utilization of waste biomass. In this study, Ni-doped lignin carbon dots (Ni-LCDs) were rapidly synthesized with a yield of 63.22 % and a quantum yield of 8.25 % using a green and simple hydrothermal method. Exploiting the inner filter effect (IFE), Cr(VI) effectively quenched the fluorescence of the Ni-LCDs, while the potent reducing agent ascorbic acid (AA) restored the quenched fluorescence, thus establishing a highly sensitive fluorescence switch sensor platform for the sequential detection of Cr(VI) and AA. Importantly, the integration of a smartphone facilitated the portability of Cr(VI) and AA detection, enabling on-site, in-situ, and real-time monitoring. Ultimately, the developed fluorescence and smartphone-assisted sensing platform was successfully applied to detect Cr(VI) in actual water samples and AA in various fruits. This study not only presents an efficient method for the conversion and utilization of waste lignin but also broadens the application scope of the CDs in the field of smart sensors.
摘要：
以木质素为原料制备荧光纳米材料是实现废弃生物质高价值利用的重要途径。在这项研究中,使用绿色简单的水热法快速合成了Ni掺杂的木质素碳点（Ni-LCD），产率为63.22％，量子产率为8.25％。利用内部过滤效应（IFE），Cr(VI)有效地猝灭Ni-LCD的荧光,而强效还原剂抗坏血酸（AA）恢复了猝灭的荧光，从而建立了一个高灵敏度的荧光开关传感器平台，用于Cr（VI）和AA的顺序检测。重要的是,智能手机的集成促进了Cr(VI)和AA检测的便携性，启用现场，就地,和实时监控。最终,所开发的荧光和智能手机辅助传感平台已成功用于检测实际水样中的Cr（VI）和各种水果中的AA。该研究不仅为废木质素的转化和利用提供了一种有效的方法，而且拓宽了CD在智能传感器领域的应用范围。
