Colorimetric visualization of Cu²⁺ based on Cu²⁺-catalyzed reaction and the signal amplification induced by K⁺-aptamer-Cu²⁺ complex

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• 作者：Xiangcong Wei^aAuthor Vitae ; Huizhong Xu^bAuthor Vitae ; Wei Li^b ; ^{weilipku@hotmail.com}Author Vitae ; Zhengbo Chen^a ; ^{czb979216@sina.com}Author Vitae
• 关键词：Peroxidase-like ; Copper ions ; Colorimetric ; G-quadruplex ; TMB-H2O2 reaction
• 刊名：Sensors and Actuators B: Chemical
• 出版年：2017
• 出版时间：31 March 2017
• 年：2017
• 卷：241
• 期：Complete
• 页码：498-503
• 全文大小：1649 K
• 卷排序：241

文摘

In this work, we report an ultrasensitive colorimetric sensing strategy for Cu2+ based on the Cu2+ catalyzed TMB-H2O2 reaction, and the signal amplification induced by aptamer-K+-Cu2+ complex. It is demonstrated that Cu2+ exhibits an intrinsic peroxidase-like catalytic activity. Thus, we utilize the catalytic activity of Cu2+ to TMB-H2O2 reaction for direct colorimetric visualization of Cu2+ for the first time. The limit of detection (LOD) is 2.6 μM. To further improve the sensitivity of Cu2+ detection, we utilized G-quadruplex-Cu2+ metalloenzyme complex formed by K+, G-rich DNA, and Cu2+ to amplify colorimetric signal of TMB-H2O2 reaction. The LOD is as low as 0.076 μM, which is 34-fold lower than that of only Cu2+-catalyzed TMB-H2O2 system (2.6 μM). The LOD shows excellent potential for monitoring ultralow levels of Cu2+ in water samples.