Highly sensitive exonuclease III-assisted fluorometric determination of silver(I) based on graphene oxide and self-hybridization of cytosine-rich ss-DNA
Highly sensitive exonuclease III-assisted fluorometric determination of silver(I) based on graphene oxide and self-hybridization of cytosine-rich ss-DNA
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DOI：
10.1007/s00604-016-1795-6
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发表时间：
2016-05-01
影响因子：
5.7
通讯作者：
Chen, Qinhua
中科院分区：
文献类型：
--
作者：
Lang, Mingjian;Li, Qian;Chen, Qinhua
We report on a method for selective fluorometric determination of Ag(I) based on the use of graphene oxide (GO) and by exploiting exonuclease III-assisted signal amplification. In the presence of Ag(I), the self-hybridization of cytosine-rich ss-DNA labeled with the fluorescent tag FAM leads to the formation of a ds-DNA that is cleaved by the catalytic action of Exo III. In the absence of Ag(I) ions, however, the tagged ss-DNA is adsorbed on the surface of GO and its fluorescence is quenched. As a result, the induction of the process by Ag(I) leads to a strong amplification of fluorescence. The method allows Ag(I) ions to be determined in the 1 to 250 nM concentration range, with a 0.1 nM detection limit. The recoveries range from 93.3 to 105.1 %, with RSDs of < 8.2 %.
