Department of Electrical, Electronic and Communications Engineering, Public University of Navarra, Ed. Los Tejos, Campus Arrosadía s/n, E-31006 Pamplona, Navarra, Spain.
Institute of Smart Cities, Public University of Navarra, Ed. Jerónimo de Ayanz, Campus Arrosadía s/n, E-31006 Pamplona, Navarra, Spain.
Sensors (Basel). 2020 Apr 22;20(8):2372. doi: 10.3390/s20082372.
A fluorescent optical fiber sensor for the detection of mercury (Hg) ions in aqueous solutions is presented in this work. The sensor was based on a fluorophore-labeled thymine (T)-rich oligodeoxyribonucleotide (ON) sequence that was directly immobilized onto the tip of a tapered optical fiber. In the presence of mercury ions, the formation of T-Hg-T mismatches quenches the fluorescence emission by the labeled fluorophore, which enables the measurement of Hg ions in aqueous solutions. Thus, in contrast to commonly designed sensors, neither a fluorescence quencher nor a complementary ON sequence is required. The sensor presented a response time of 24.8 seconds toward 5 × 10 M Hg. It also showed both good reversibility (higher than the 95.8%) and selectivity: the I/I variation was 10 times higher for Hg ions than for Mn ions. Other contaminants examined (Co, Ag, Cd, Ni, Ca, Pb, Mn, Zn, Fe, and Cu) presented an even lower interference. The limit of detection of the sensor was 4.73 × 10 M Hg in buffer solution and 9.03 × 10 M Hg in ultrapure water, and was also able to detect 5 × 10 M Hg in tap water.
本文提出了一种用于检测水溶液中汞（Hg）离子的荧光光纤传感器。该传感器基于荧光标记的胸腺嘧啶（T）丰富的寡脱氧核苷酸（ON）序列，该序列直接固定在锥形光纤的尖端。在汞离子存在下，形成的 T-Hg-T 错配会使标记荧光团的荧光发射猝灭，从而能够测量水溶液中的 Hg 离子。因此，与通常设计的传感器不同，既不需要荧光猝灭剂也不需要互补的 ON 序列。该传感器对 5×10 M Hg 的响应时间为 24.8 秒。它还表现出良好的可逆性（高于 95.8%）和选择性：Hg 离子的 I/I 变化比 Mn 离子高 10 倍。检查的其他污染物（Co、Ag、Cd、Ni、Ca、Pb、Mn、Zn、Fe 和 Cu）的干扰更小。该传感器在缓冲溶液中的检测限为 4.73×10 M Hg，在超纯水中的检测限为 9.03×10 M Hg，并且还能够检测自来水中的 5×10 M Hg。
