适体
化学
脱氧核酶
G-四倍体
检出限
血红素
寡核苷酸
吸光度
过氧化物酶
镉
序列(生物学)
组合化学
色谱法
生物化学
分子生物学
DNA
酶
有机化学
血红素
生物
作者
Bin Zhou,Ya-Ting Chen,Xinyi Yang,Yongsheng Wang,Xi‐Jiang Hu,Qing-Li Suo
出处
期刊:Analytical Sciences
[Japan Society for Analytical Chemistry]
日期:2018-11-02
卷期号:35 (3): 277-282
被引量:8
标识
DOI:10.2116/analsci.18p248
摘要
We rationally designed an ultrasensitive and label-free sensing platform for determination of cadmium (Cd). The sensing platform contains G-quadruplex-Cd(II) specific aptamer (GCDSA) constructed by incorporating G-rich sequence at the end of 5' and the critical domain of the Cd-4 aptamer. GCDSA designed act as both a special recognition sequence for Cd2+ and a signal DNAzyme. In absence of Cd2+, GCDSA may mainly exist in a random coil sequence. Upon addition of Cd2+, GCDSA could probably be induced to fold into a G-quadruplex structure. The generation of plentiful active G-quadruplex interacts with hemin to form a peroxidase-like DNAzyme, leading to increased absorbance signal of the sensing system. ΔA was directly proportional to the two segments of concentrations for Cd2+, with the detection of limit of 0.15 nM. The proposed method avoids the labeled oligonucleotides and allows directly quantitative analysis of the samples by cheap instruments, with an excellent dynamic range.
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