Zhang Ya-Nan, Liang Wenchao, Li Like, Zhang Hongrui, Cao Shangwen, Han Bo, Zhao Yong
College of Information Science and Engineering, Northeastern University, Shenyang, 110819, China; Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology, Qinhuangdao, 066004, China; State Key Laboratory of Synthetical Automation for Process Industries, Shenyang, 110819, China.
College of Information Science and Engineering, Northeastern University, Shenyang, 110819, China.
Anal Chim Acta. 2024 Dec 1;1331:343300. doi: 10.1016/j.aca.2024.343300. Epub 2024 Oct 3.
Copper ion (Cu), a crucial heavy metal ion, is closely associated with human health and the ecological environment. Imbalances in Cu can result in health issues for humans and damage to the ecosystem. Therefore, it is essential to detect Cu in the environment. However, current Cu sensors still face challenges such as limited detection range, poor detection limits, high costs, and complex preparation processes. Clearly, there is a need for a Cu sensor with an extensive detection range, low detection limit, cost-effectiveness, and simple preparation methods that enable online monitoring and real-time measurement of Cu.
In this paper, a high-performance optical fiber fluorescent Cu sensor based on polyethylene glycol diacrylate (PEGDA) hydrogel encapsulated CdSe/ZnS quantum dots (QDs) is designed and fabricated. Due to the porous nature of PEGDA hydrogels, large-diameter CdSe/ZnS QDs are confined within the hydrogels, while small molecules Cu are allowed to permeate them. Cu reacts with QDs, resulting in the fluorescence quenching of QDs, which enables the detection of Cu. Experimental results show that the sensor can quantitatively analyze Cu in the concentration range of 0.1-200 μM, with a limit of detection (LOD) of only 0.8 nM, and the fastest response time is only 5 s. Additionally, the sensor exhibits strong specificity, has been successfully applied to real water sample detection, demonstrates good stability, and shows great potential for real-time Cu detection.
The sensor possesses a large detection range and low LOD, and the synthesis of its core fluorescent probe is straightforward and expedient. Specifically, the fluorescent probe can be synthesized by subjecting a solution of hydrogel precursors doped with CdSe/ZnS QDs to UV irradiation for approximately 2 min. This method is particularly suitable for monitoring confined environments and holds significant implications for the production of Cu sensors capable of real-time detection.
铜离子（Cu）作为一种关键的重金属离子，与人类健康和生态环境密切相关。铜离子失衡会给人类带来健康问题，并对生态系统造成破坏。因此，检测环境中的铜离子至关重要。然而，目前的铜离子传感器仍面临诸多挑战，如检测范围有限、检测限较差、成本高昂以及制备过程复杂等。显然，需要一种具有广泛检测范围、低检测限、成本效益高且制备方法简单的铜离子传感器，以实现对铜离子的在线监测和实时测量。
本文设计并制备了一种基于聚乙二醇二丙烯酸酯（PEGDA）水凝胶包裹的CdSe/ZnS量子点（QDs）的高性能光纤荧光铜离子传感器。由于PEGDA水凝胶的多孔性质，大直径的CdSe/ZnS量子点被限制在水凝胶内部，而小分子铜离子则可以渗透其中。铜离子与量子点发生反应，导致量子点荧光猝灭，从而实现对铜离子的检测。实验结果表明，该传感器能够在0.1 - 200 μM的浓度范围内对铜离子进行定量分析，检测限（LOD）仅为0.8 nM，最快响应时间仅为5 s。此外，该传感器具有很强的特异性，已成功应用于实际水样检测，显示出良好的稳定性，在铜离子实时检测方面具有巨大潜力。
该传感器具有较大的检测范围和较低的检测限，其核心荧光探针的合成简单便捷。具体而言，通过对掺杂有CdSe/ZnS量子点的水凝胶前体溶液进行约2分钟的紫外线照射即可合成荧光探针。该方法特别适用于监测受限环境，对于能够进行实时检测的铜离子传感器的生产具有重要意义。
