Liu Zhen, Li Gengsong, Zhang Aoyan, Zhou Guiyao, Huang Xuguang
Opt Express. 2021 Jul 19;29(15):22992-23005. doi: 10.1364/OE.434687.
An ultrahigh sensitive optical fiber sensor for trace detection of Cu concentration in aqueous solution with temperature calibration has been developed in this article. Based on the intermodal interference, the sensor is coated with a hydrogel sensing membrane with specific binding to Cu on the no-core fiber/single mode fiber/no-core fiber structure by using our new spray coating method. The imidazole group in the sensing film combines with Cu to produce chelation, which changes the refractive index of the sensing film. The Cu at trace concentration can be detected by monitoring the displacement of the interference trough. The experimental limit of detection of 3.0×10 mol/L can be achieved with the spectral resolution of 0.02 nm. The sensor has also long-term stability of the concentration measurement with the average standard deviation of 1.610×10 mol/L over 2 hours observation time and can be compensated the influence of ambient temperature on concentration detection by conducting the temperature calibration. In addition, the sensor has the advantages of strong specificity, simple fabrication and low cost.
本文开发了一种用于水溶液中痕量铜浓度检测并具有温度校准功能的超高灵敏度光纤传感器。基于模间干涉，通过我们新的喷涂方法，在无芯光纤/单模光纤/无芯光纤结构上涂覆与铜具有特异性结合的水凝胶传感膜。传感膜中的咪唑基团与铜结合产生螯合作用，从而改变传感膜的折射率。通过监测干涉谷的位移可以检测痕量浓度的铜。在光谱分辨率为0.02 nm的情况下，可实现3.0×10⁻⁹ mol/L的实验检测限。该传感器在浓度测量方面还具有长期稳定性，在2小时的观察时间内平均标准偏差为1.610×10⁻⁹ mol/L，并且可以通过进行温度校准来补偿环境温度对浓度检测的影响。此外，该传感器具有特异性强、制作简单和成本低的优点。
