Colorimetric Strategy for Highly Sensitive and Selective Simultaneous Detection of Histidine and Cysteine Based on G-Quadruplex-Cu(II) Metalloenzyme

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• 作者：Changtong Wu ; Daoqing Fan ; Chunyang Zhou ; Yaqing Liu ; Erkang Wang
• 刊名：Analytical Chemistry
• 出版年：2016
• 出版时间：March 1, 2016
• 年：2016
• 卷：88
• 期：5
• 页码：2899-2903
• 全文大小：359K
• ISSN：1520-6882

文摘

In this present work, we proposed a colorimetric strategy for simultaneous detection of histidine and cysteine based on G-quadruplex-Cu(II) metalloenzyme for the first time. Because of the adding of histidine or cysteine, the formation of G-quadruplex-Cu(II) metalloenzyme will be disturbed, thus the catalytic activity to TMB-H₂O₂ reaction is inversely proportional to the concentration of histidine or cysteine. With this strategy, the limit of detection in experimental measurement for histidine and cysteine is 10 nM and 5 nM, respectively, which are both lower than previous colorimetric arrays. With the help of NEM, cysteine is alkylated and the reaction between Cu²⁺ is inhibited, so the selectivity can also be guaranteed. The cost is quite low since the developed array is label free and enzyme free by using low-cost DNA and Cu²⁺. More importantly, the colorimetric detection operation is very simple without any further modification process.