Laboratory of Nanomaterial Science, Department of Chemistry, New Mexico Tech, Socorro, NM 87801, United States.
Biosens Bioelectron. 2010 Jul 15;25(11):2431-5. doi: 10.1016/j.bios.2010.03.038. Epub 2010 Apr 7.
We demonstrate a fluorescence-based, label-free detection scheme that reports the presence of Hg(II) ion using photon upconverting nanoparticles. A single-stranded DNA containing a number of thymine bases to be used as the Hg(2+)-capturing element is covalently attached to the photon upconverting NaYF(4):Yb(3+),Tm(3+) nanoparticles. Under the illumination of 980 nm laser, energy transfer takes place between the NaYF(4):Yb(3+),Tm(3+) nanoparticles as the donor and SYBR Green I, a DNA intercalating dye, as the acceptor. By monitoring the ratio of the acceptor emission to the donor emission, we can quantitatively detect the presence of the mercuric ions with a directly observed detection limit of 0.06 nM. The remarkably high signal-to-noise ratio of photon upconverting particles leads to very high sensitivity and specificity without the need of fluorophore labeling. The sensor also does not suffer from photobleaching.
我们展示了一种基于荧光的、无需标记的检测方案，该方案使用上转换纳米粒子报告 Hg(II)离子的存在。一条包含多个胸腺嘧啶碱基的单链 DNA 被用作 Hg(2+)捕获元件，通过共价键连接到上转换 NaYF(4):Yb(3+),Tm(3+)纳米粒子上。在 980nm 激光的照射下，NaYF(4):Yb(3+),Tm(3+)纳米粒子作为供体与 SYBR Green I（一种 DNA 嵌入染料）之间发生能量转移。通过监测受体发射与供体发射的比值，我们可以定量检测到汞离子的存在，其直接观察到的检测限为 0.06 nM。上转换粒子的高信噪比导致了非常高的灵敏度和特异性，而无需荧光标记。该传感器也不会受到光漂白的影响。
