Wei Yong, Tang Yixiong, Shao Yabin, Liu Chunlan, Shi Chen, Wang Xingkai, Liu Chunbiao, Liu Zhihai
Opt Lett. 2024 Aug 1;49(15):4158-4161. doi: 10.1364/OL.524028.
A fiber SPR sensor can achieve rapid and portable detection of trivalent arsenic ions (As) in drinking water or food, but their sensitivity and detection limit need to be further improved and developed toward specific detection. This article proposed the implementation of the SPR sensor using a biased core fiber spiral coarse cone structure. The fine core of the biased core fiber was used to reduce the mode of transmitted light. By controlling the pitch of the spiral core to control the SPR incidence angle, a significant increase in the sensitivity of the fiber SPR sensor was achieved. Meanwhile, the harmless glutathione (GSH) was modified on the surface of the sensing gold film to achieve the specific detection of As. The experimental results indicate that the spiral coarse cone fiber SPR sensor proposed in this article has a detection sensitivity of 32.48 nm/ppb for As, with a detection limit as low as 0.011 ppb, meeting the detection requirements of the World Health Organization for As in water, which provides a new feasible solution for fast, portable, and highly sensitive detection of metal ions in water and food.
光纤表面等离子体共振（SPR）传感器能够对饮用水或食品中的三价砷离子（As）进行快速且便携的检测，但其灵敏度和检测限仍需进一步提高，并朝着特异性检测方向发展。本文提出采用偏芯光纤螺旋粗锥结构来实现SPR传感器。利用偏芯光纤的细芯来减少传输光的模式。通过控制螺旋芯的螺距来控制SPR入射角，实现了光纤SPR传感器灵敏度的显著提高。同时，在传感金膜表面修饰无害的谷胱甘肽（GSH）以实现对As的特异性检测。实验结果表明，本文提出的螺旋粗锥光纤SPR传感器对As的检测灵敏度为32.48 nm/ppb，检测限低至0.011 ppb，满足世界卫生组织对水中As的检测要求，为快速、便携且高灵敏度地检测水和食品中的金属离子提供了一种新的可行解决方案。
