Liu Shanshan, Liu Weijie, Chen Xiuhong, Lai Yunping, Zhang Tao
Hebei Center for New Inorganic Optoelectronic Nanomaterial Research, Hebei Key Laboratory of Heterocyclic Compounds, College of Chemistry, Chemical Engineering and Materials, Technology Innovation Center of Nanosized Natural Products and New Materials of Hebei Province, Handan University, Handan, 056005, China.
School of Materials Science and Engineering, Beihang University, Beijing, 100191, China.
J Fluoresc. 2025 Mar 18. doi: 10.1007/s10895-025-04230-0.
Carbon dots (CDs) have recently regarded as an attractive fluorescent sensor for water quality detection. However, the actual detection application of CDs is limited owing to the low fluorescence quantum yield (QY) and unclear ion detection mechanism. Here, nitrogen doped CDs (N-CDs) with abundant amide groups, which were easy to prepare using urea and citric acid under mild reaction conditions and displayed great light absorption and strong fluorescence performance with a fluorescence QY of up to 26.6%. More importantly, N-CDs could achieve selective detection of iron ion (Fe) and its concentrations as low as 0.47 µM in water. Meanwhile, N-CDs exhibited a good linear relationship within the concentration range of 0.5-500 µM of Fe. This mainly because the introduction of amide groups of N-CDs not only could serve as both donors (NH-), but also acceptors (C = O) for hydrogen bonding, which consequently increased multifunctional fluorescent recognition sites and formed coordination interactions with metal ions, and ultimately achieved fluorescence detection of ions. Therefore, the preparation of N-CDs rich in amide groups provides a promising strategy for rapid and efficient detection of Fe ions for water quality detection applications.
碳点（CDs）最近被认为是一种用于水质检测的有吸引力的荧光传感器。然而，由于荧光量子产率（QY）低和离子检测机制不明确，CDs的实际检测应用受到限制。在此，具有丰富酰胺基团的氮掺杂碳点（N-CDs），在温和反应条件下使用尿素和柠檬酸易于制备，具有良好的光吸收和强荧光性能，荧光QY高达26.6%。更重要的是，N-CDs能够实现对铁离子（Fe）的选择性检测，其在水中的浓度低至0.47 μM。同时，N-CDs在Fe的0.5 - 500 μM浓度范围内表现出良好的线性关系。这主要是因为N-CDs酰胺基团的引入不仅可以作为氢键的供体（NH-），还可以作为受体（C = O），从而增加了多功能荧光识别位点并与金属离子形成配位相互作用，最终实现了离子的荧光检测。因此，富含酰胺基团的N-CDs的制备为水质检测应用中快速高效检测Fe离子提供了一种有前景的策略。
