Environmental Analytical Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok, 10330, Thailand.
Supramolecular Chemistry Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Pathumwan, Bangkok, 10330, Thailand.
Talanta. 2021 Aug 15;231:122371. doi: 10.1016/j.talanta.2021.122371. Epub 2021 Apr 23.
In this work, a highly sensitive colorimetric paper-based optode for the determination of thiocyanate in urine samples was developed for the first time. The cocktail solution of the optode was composed of 5,10,15,20-tetrakis(4-octyloxyphenyl)porphyrin cobalt(II) complex (L), tridodecylmethylammonium chloride (TDMACl), 2-nitrophenyl octyl ether, and polyvinyl chloride as an ionophore, an ion exchanger, a plasticizer, and a polymer, respectively. The paper-based optode responded to thiocyanate by increasing the blue component in the RGB index and a visible change, with the naked-eye, of the optode color from pink to green was observed. From the central composite design, the optimized conditions that yielded the highest sensitivity were 4.70 mmol/kg TDMACl and 13.75 mmol/kg L. The developed optode sensor was highly selective and responded to thiocyanate over other anions, with a working range of 0.001-5 mM and with a coefficient of determination (R) of 0.9915. The limits of detection using naked-eye and camera were determined to be 50.0 μM and 1.26 μM, respectively. In addition, the LOD and LOQ estimated from the standard deviation of the blank were 0.65 and 1.87 μM, respectively. Furthermore, this sensor was successfully applied to the detection of thiocyanate in urine samples from non-smokers and smokers. The results were in good agreement with the standard ion chromatography (IC) technique. This developed paper-based optode sensor was simple, low-cost, portable, and easy to use as a sensing device without any complicated instrument.
在这项工作中，首次开发了一种用于测定尿样中硫氰酸盐的高灵敏度比色纸基光学传感器。光学传感器的混合溶液由 5,10,15,20-四（4-辛氧基苯基）卟啉钴（II）配合物（L）、三辛基甲基氯化铵（TDMACl）、2-硝基苯辛醚和聚氯乙烯组成，分别作为离子载体、离子交换剂、增塑剂和聚合物。纸基光学传感器通过增加 RGB 指数中的蓝色成分以及光学传感器颜色从粉红色变为绿色的可见变化来响应硫氰酸盐。通过中心复合设计，得出了最高灵敏度的优化条件为 4.70 mmol/kg TDMACl 和 13.75 mmol/kg L。所开发的光学传感器传感器具有高度选择性，对硫氰酸盐的响应优于其他阴离子，工作范围为 0.001-5 mM，相关系数（R）为 0.9915。使用肉眼和相机检测的检出限分别确定为 50.0 μM 和 1.26 μM。此外，空白的标准偏差估计的 LOD 和 LOQ 分别为 0.65 和 1.87 μM。此外，该传感器成功应用于检测非吸烟者和吸烟者尿液样本中的硫氰酸盐。结果与标准离子色谱（IC）技术吻合良好。该开发的纸基光学传感器简单、低成本、便携，易于用作传感装置，无需任何复杂仪器。
