Jiang Bang-Ping, Zhou Bo, Shen Xing-Can, Yu Yun-Xiang, Ji Shi-Chen, Wen Chang-Chun, Liang Hong
Ministry of Education Key Laboratory for the Chemistry and, Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Science, Guangxi Normal University, Guilin, 541004 (P. R. China).
Chemistry. 2015 Dec 21;21(52):18993-9. doi: 10.1002/chem.201502731. Epub 2015 Oct 30.
Solid-state fluorescence sensing is one of the most appealing detection techniques because of its simplicity and convenience in practical operation. Herein, we report the development of a red-emitting carbon dots (RCDs)-based material as a solid-state fluorescence sensor for the selective probing of gaseous ammonia. The RCDs were prepared by a low-cost, one-step carbonization method using sugar cane bagasse as the carbon precursor. The pristine RCDs were then directly coated on polyvinylidene fluoride membrane to produce a new fluorescence sensor capable of selectively distinguishing toxic gaseous ammonia from other analyte vapors through sensitive fluorescence quenching with a low detection limit. More importantly, the interfacial response mechanism occurring on the surface of the RCDs has been studied by X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and Raman measurements. The results indicate that fluorescence quenching in the RCDs might result from ammonia-induced Michael addition through insertion of N into the C=C group and deprotonation of the carboxyl group. To the best of our knowledge, this is the first report that provides clear insight into the mechanism of surface chemistry on CDs in the solid state.
固态荧光传感因其实际操作的简单性和便利性而成为最具吸引力的检测技术之一。在此，我们报告了一种基于发红光碳点（RCDs）的材料的开发，作为用于选择性探测气态氨的固态荧光传感器。RCDs通过使用甘蔗渣作为碳前驱体的低成本一步碳化法制备。然后将原始RCDs直接涂覆在聚偏二氟乙烯膜上，以制备一种新型荧光传感器，该传感器能够通过灵敏的荧光猝灭以低检测限从其他分析物蒸气中选择性地区分有毒气态氨。更重要的是，通过X射线光电子能谱、傅里叶变换红外光谱和拉曼测量研究了RCDs表面发生的界面响应机制。结果表明，RCDs中的荧光猝灭可能是由于氨诱导的迈克尔加成，即N插入C=C基团以及羧基去质子化。据我们所知，这是第一份对固态CDs表面化学机制提供清晰见解的报告。
