State Key Laboratory of Medicinal Chemical Biology, and Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin 300071, China.
Analyst. 2012 May 7;137(9):2124-8. doi: 10.1039/c2an35126a. Epub 2012 Mar 22.
A simple and efficient colorimetric method for the naked-eye detection and quantification of histidine in biological fluids was developed based on an indicator-displacement assay (IDA) and the Ni(2+)-histidine affinity pair. In this IDA approach, a commercially available dye, murexide, was used as the indicator and the selective detection of histidine was achieved based on the competition between indicator and histidine for the binding with Ni(2+). The competition of histidine with murexide for Ni(2+) resulted in an obvious color change of the solution from yellow to purple, and the permitted naked-eye detection of trace histidine. The developed bioassay allows the rapid, sensitive and selective detection of histidine in urine samples, and does not need complicated sample pretreatment. The detection limit was 0.4 μM with a linear range from 2 to 30 μM. The relative standard deviation for 11 replicate detections of 8 μM histidine was 2.0%. The developed sensor was successfully applied to the determination of histidine in human urine samples with recoveries from 97 to 105%.
基于指示剂置换分析（IDA）和 Ni(2+)-组氨酸亲和对，开发了一种用于在生物流体中进行组氨酸的肉眼检测和定量的简单、高效的比色法。在这种 IDA 方法中，使用了一种市售的染料，即玫瑰红，作为指示剂，并且基于指示剂和组氨酸与 Ni(2+)的结合竞争，实现了组氨酸的选择性检测。组氨酸与玫瑰红竞争 Ni(2+)导致溶液颜色从黄色变为紫色，从而可以肉眼检测痕量组氨酸。所开发的生物测定法允许在尿液样品中快速、灵敏和选择性地检测组氨酸，并且不需要复杂的样品预处理。检测限为 0.4 μM，线性范围为 2 至 30 μM。对 8 μM 组氨酸的 11 次重复检测的相对标准偏差为 2.0%。该传感器成功地应用于人尿液样品中组氨酸的测定，回收率为 97%至 105%。
