Highly selective and sensitive method for cysteine detection based on fluorescence resonance energy transfer between FAM-tagged ssDNA and graphene oxide
- 作者：Hongli Liu ; Yuhui Wang ; Aiguo Shen ; Xiaodong Zhou ; zhouxd@whu.edu.cn ; Jiming Hu ; jmhu@whu.edu.cn
- 关键词：Graphene oxide ; Fluorescence resonance energy transfer ; Cysteine
- 刊名：Talanta
- 出版年：2012
- 期刊代码：106_00399140
- 类别：ch
- 出版时间：15 May, 2012
- 卷：93
- 期：Complete
- 页码：330-335
- 文件大小：955 K
摘要
In this work, a new platform for effective sensing cysteine (Cys) was developed based on fluorescence resonance energy transfer (FRET) between FAM-tagged single-stranded DNA (FAM-ssDNA) and graphene oxide (GO). Due to the noncovalent assembly between FAM-ssDNA and GO, fluorescence quenching of the FAM took place because of FRET. This method relied on the competitive ligation of Ag+ by Cys and 鈥渃ytosine-cytosine鈥?(C-C) mismatches in a FAM-labeled DNA strand of the self-hybridizing strand. At first, enough amount of Ag+ was introduced to bind 鈥淐-C鈥?mismatches and form double-stranded DNA (dsDNA), which had weak affinity to GO and kept FAM away from GO surface. However, the presence of Cys removed Ag+ away from 鈥渃ytosine-Ag+-cytosine鈥?(C-Ag+-C) base pairs, leading to the formation of ssDNA again and FRET, and then fluorescence of the FAM-ssDNA was efficiently quenched. The fluorescence intensity decrease was found to be proportional to the increase of concentration of Cys in both aqueous buffer (2-200 nM) and human serum (5-200 nM), and the sensitivity of the proposed method towards Cys was much higher than that of other reported assays for Cys.