Highly sensitive multiplexed heavy metal detection using quantum-dot-labeled DNAzymes.
Highly sensitive multiplexed heavy metal detection using quantum-dot-labeled DNAzymes.
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DOI：
10.1021/nn1021988
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发表时间：
2010-10
期刊：
影响因子：
17.1
通讯作者：
Chung-Shieh Wu;Maung Kyaw Khaing Oo;Xudong Fan
中科院分区：
文献类型：
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作者：
Chung-Shieh Wu;Maung Kyaw Khaing Oo;Xudong Fan
我们开发了基于量子点和DNA酶的高灵敏度和特异性纳米传感器，用于多重检测液体中的重金属离子。量子点被涂上一层薄的二氧化硅层，以提高稳定性和更高的量子产率，同时保持相对较小的尺寸，以实现高效的能量转移。通过将猝灭剂标记的DNA酶偶联到羧基硅烷化的量子点表面，构建了量子点-DNA酶纳米传感器。在金属离子存在下，由于DNA酶的切割，发射恢复。使用单个激光激发源可在25 min内完成检测。Pb（2+）和Cu（2+）的检测限分别为0.2和0.5 nM，这比最近用染料分子获得的结果提高了50倍和70倍。还使用两种不同颜色的QD证明了多重检测，显示Pb（2+）检测和Cu（2+）检测之间的串扰可忽略不计。
We developed highly sensitive and specific nanosensors based on quantum dots (QDs) and DNAzyme for multiplexed detection of heavy metal ions in liquid. The QDs were coated with a thin silica layer for increased stability and higher quantum yield while maintaining a relatively small size for highly efficient energy transfer. The QD-DNAzyme nanosensors were constructed by conjugating quencher-labeled DNAzymes onto the surface of carboxyl-silanized QDs. In the presence of metal ions, the emission is restored due to the cleavage of DNAzymes. The detection could be completed within 25 min with a single laser excitation source. The detection limit of 0.2 and 0.5 nM was experimentally achieved for Pb(2+) and Cu(2+), respectively, which is a 50- and 70-fold improvement over the recent results obtained with dye molecules. Multiplexed detection was also demonstrated using two different colors of QDs, showing negligible cross-talk between the Pb(2+) detection and Cu(2+) detection.