Aslan Kadir, Malyn Stuart N, Geddes Chris D
Institute of Fluorescence, Laboratory for Advanced Medical Plasmonics, Medical Biotechnology Center, University of Maryland Biotechnology Institute, 725 West Lombard St, Baltimore, MD 21201, USA.
Biochem Biophys Res Commun. 2006 Sep 22;348(2):612-7. doi: 10.1016/j.bbrc.2006.07.093. Epub 2006 Jul 28.
A new, fast, and sensitive DNA hybridization assay platform based on microwave-accelerated metal-enhanced fluorescence (MAMEF) is presented. Thiolated oligonucleotide anchors were immobilized onto silver nanoparticles on a glass substrate. The hybridization of the complementary fluorescein-labeled DNA target with the surface-bound oligonucleotides was completed within 20 s upon heating with low-power microwaves. In addition, the signal is optically amplified, a consequence of close proximity of the fluorophore to the silvered substrate. In this proof-of-principle methodology, as low as 50 nM of a target DNA was detected, although we envisage far-lower detection limits. Control experiments, where the surface-bound oligonucleotide was omitted, were also performed to determine the extent of non-specific binding. In these studies a significantly reduced non-specific adsorption was found when using microwave heating near to silvered structures as compared to room temperature incubation. These findings suggest that MAMEF could be a most useful alternative to the DNA hybridization assays used today, especially with regard to substantially increasing both the assay rapidity and sensitivity.
本文介绍了一种基于微波加速金属增强荧光（MAMEF）的新型、快速且灵敏的DNA杂交检测平台。将硫醇化寡核苷酸锚固定在玻璃基板上的银纳米颗粒上。在用低功率微波加热后，20秒内即可完成互补荧光素标记的DNA靶标与表面结合寡核苷酸的杂交。此外，由于荧光团与镀银基板距离很近，信号得到光学放大。在这种原理验证方法中，检测到的靶标DNA低至50 nM，不过我们预计检测限会低得多。还进行了对照实验，即省略表面结合的寡核苷酸，以确定非特异性结合的程度。在这些研究中发现，与室温孵育相比，在镀银结构附近使用微波加热时，非特异性吸附显著降低。这些发现表明，MAMEF可能是当今使用的DNA杂交检测方法的一种非常有用的替代方法，特别是在大幅提高检测速度和灵敏度方面。
