Hushiarian Roozbeh, Yusof Nor Azah, Abdullah Abdul Halim, Ahmad Shahrul Ainliah Alang, Dutse Sabo Wada
Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
Molecules. 2014 Apr 9;19(4):4355-68. doi: 10.3390/molecules19044355.
Although nanoparticle-enhanced biosensors have been extensively researched, few studies have systematically characterized the roles of nanoparticles in enhancing biosensor functionality. This paper describes a successful new method in which DNA binds directly to iron oxide nanoparticles for use in an optical biosensor. A wide variety of nanoparticles with different properties have found broad application in biosensors because their small physical size presents unique chemical, physical, and electronic properties that are different from those of bulk materials. Of all nanoparticles, magnetic nanoparticles are proving to be a versatile tool, an excellent case in point being in DNA bioassays, where magnetic nanoparticles are often used for optimization of the hybridization and separation of target DNA. A critical step in the successful construction of a DNA biosensor is the efficient attachment of biomolecules to the surface of magnetic nanoparticles. To date, most methods of synthesizing these nanoparticles have led to the formation of hydrophobic particles that require additional surface modifications. As a result, the surface to volume ratio decreases and nonspecific bindings may occur so that the sensitivity and efficiency of the device deteriorates. A new method of large-scale synthesis of iron oxide (Fe3O4) nanoparticles which results in the magnetite particles being in aqueous phase, was employed in this study. Small modifications were applied to design an optical DNA nanosensor based on sandwich hybridization. Characterization of the synthesized particles was carried out using a variety of techniques and CdSe/ZnS core-shell quantum dots were used as the reporter markers in a spectrofluorophotometer. We showed conclusively that DNA binds to the surface of ironoxide nanoparticles without further surface modifications and that these magnetic nanoparticles can be efficiently utilized as biomolecule carriers in biosensing devices.
尽管纳米颗粒增强型生物传感器已得到广泛研究，但很少有研究系统地表征纳米颗粒在增强生物传感器功能方面的作用。本文描述了一种成功的新方法，即DNA直接与氧化铁纳米颗粒结合，用于光学生物传感器。各种具有不同特性的纳米颗粒已在生物传感器中得到广泛应用，因为它们小的物理尺寸呈现出与块状材料不同的独特化学、物理和电子特性。在所有纳米颗粒中，磁性纳米颗粒被证明是一种多功能工具，一个很好的例子是在DNA生物测定中，磁性纳米颗粒经常用于优化目标DNA的杂交和分离。成功构建DNA生物传感器的关键步骤是将生物分子有效附着到磁性纳米颗粒表面。迄今为止，大多数合成这些纳米颗粒的方法都会导致形成需要额外表面修饰的疏水性颗粒。结果，表面体积比降低，可能会发生非特异性结合，从而使设备的灵敏度和效率降低。本研究采用了一种大规模合成氧化铁（Fe3O4）纳米颗粒的新方法，该方法可使磁铁矿颗粒处于水相中。通过进行小的修改来设计基于夹心杂交的光学生物DNA纳米传感器。使用各种技术对合成颗粒进行表征，并在荧光分光光度计中使用CdSe/ZnS核壳量子点作为报告标记。我们确凿地表明，DNA无需进一步表面修饰即可与氧化铁纳米颗粒表面结合，并且这些磁性纳米颗粒可以有效地用作生物传感设备中的生物分子载体。
