Ultrasensitive colorimetric carcinoembryonic antigen biosensor based on hyperbranched rolling circle amplification.
Ultrasensitive colorimetric carcinoembryonic antigen biosensor based on hyperbranched rolling circle amplification.
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DOI：
10.1039/c4an00417e
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发表时间：
2014-07
期刊：
影响因子：
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通讯作者：
K. Liang;S. Zhai;Zhidong Zhang;Xiaoyang Fu;Jingwei Shao;Zhenyu Lin;Bin Qiu;Guonan Chen
中科院分区：
文献类型：
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作者：
K. Liang;S. Zhai;Zhidong Zhang;Xiaoyang Fu;Jingwei Shao;Zhenyu Lin;Bin Qiu;Guonan Chen
本研究基于超支化滚环扩增（hyperbranched rolling circle amplification， HRCA）技术开发了一种具有高灵敏度和特异性的癌胚抗原（CEA）比色生物传感器。由于CEA适体与靶基因（CEA）的亲和性高，可以与靶基因（CEA）结合形成复合物，而引入的CDNA不能与适体杂交。因此，自由的CDNA可以通过HRCA反应繁殖，形成大量单链DNA （ss-DNA）。ss-DNA可以很容易地吸附在AuNPs上，防止盐诱导的AuNPs聚集，从而导致系统颜色的变化。结果发现，在5 pM-0.5 nM范围内，吸光度强度比（A520/A660）与目标物浓度呈线性关系，检出限低至2 pM （S/N = 3）。
In this study, a hyperbranched rolling circle amplification (HRCA)-based colorimetric biosensor for carcinoembryonic antigen (CEA) is developed with high sensitivity and specificity. A CEA aptamer can bind with its target (CEA) to form a complex due to their high affinity, and the introduced CDNA cannot hybridize with the aptamer. Thus, free CDNA can propagate the HRCA reaction to form a large number of single-stranded DNA (ss-DNA). ss-DNA can be easily adsorbed onto AuNPs and prevent salt-induced AuNPs aggregation, which causes the change in the color of the system. It is found that the absorbance intensity ratio (A520/A660) has a linear relationship with the concentration of the target in the range of 5 pM-0.5 nM, and the detection limit is as low as 2 pM (S/N = 3).