Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, China.
Analyst. 2011 Dec 21;136(24):5169-74. doi: 10.1039/c1an15783c. Epub 2011 Oct 26.
In this paper, we have reported a sensitive assay for fluorescence "turn-on" detection of Pb(2+) in aqueous solutions based on FRET between gold nanorods (GNRs) and the FAM-labeled substrate strand of 8-17DNAzyme. The fluorescence of the FAM-labeled substrate strand is quenched when 8-17DNAzyme is adsorbed on GNRs surface through electrostatic interaction. In the presence of lead ions, the fluorescence is restored due to the decrease of FRET efficiency caused by the specific cleavage of the FAM-labeled substrate strand by the enzyme, which weakens the electrostatic interaction between the GNRs and short FAM-labeled DNA fragment. The interference of eleven common metal ions has been tested, indicating that Pb(2+) can be selectively detected. This method exhibits a high sensitivity for Pb(2+) with a detection limit of 61.8 pM and a linear range from 0.1 nM to 100 nM. It is a simple, sensitive, and selective method for Pb(2+) detection. Moreover, this sensing system obtained satisfying results for Pb(2+) detection in tap water samples.
本文报道了一种基于金纳米棒（GNRs）与 8-17DNA 酶标记的底物链之间的 FRET，用于荧光“开启”检测水溶液中 Pb(2+)的灵敏分析方法。当 8-17DNA 酶通过静电相互作用吸附在 GNRs 表面时，标记的底物链的荧光被猝灭。在存在铅离子的情况下，由于酶对 FAM 标记的底物链的特异性切割导致 FRET 效率降低，荧光得到恢复，从而减弱了 GNRs 与短的 FAM 标记 DNA 片段之间的静电相互作用。已经测试了十一种常见金属离子的干扰，表明可以选择性检测 Pb(2+)。该方法对 Pb(2+)具有高灵敏度，检测限为 61.8 pM，线性范围为 0.1 nM 至 100 nM。这是一种简单、灵敏和选择性的 Pb(2+)检测方法。此外，该传感系统在自来水中的 Pb(2+)检测中获得了令人满意的结果。
