University of Auckland, Private Bag-92019, Auckland, New Zealand.
Biosens Bioelectron. 2013 Jul 15;45:136-40. doi: 10.1016/j.bios.2013.01.044. Epub 2013 Feb 11.
Despite the plethora of DNA sensor platforms available, a portable, sensitive, selective and economic sensor able to rival current fluorescence-based techniques would find use in many applications. In this research, probe oligonucleotide-grafted particles are used to detect target DNA in solution through a resistive pulse nanopore detection technique. Using carbodiimide chemistry, functionalized probe DNA strands are attached to carboxylated dextran-based magnetic particles. Subsequent incubation with complementary target DNA yields a change in surface properties as the two DNA strands hybridize. Particle-by-particle analysis with resistive pulse sensing is performed to detect these changes. A variable pressure method allows identification of changes in the surface charge of particles. As proof-of-principle, we demonstrate that target hybridization is selectively detected at micromolar concentrations (nanomoles of target) using resistive pulse sensing, confirmed by fluorescence and phase analysis light scattering as complementary techniques. The advantages, feasibility and limitations of using resistive pulse sensing for sample analysis are discussed.
尽管有大量的 DNA 传感器平台可供选择，但能够与当前基于荧光的技术相媲美的便携式、灵敏、选择性和经济的传感器将在许多应用中找到用途。在这项研究中，通过电阻脉冲纳米孔检测技术，使用探针寡核苷酸接枝颗粒来检测溶液中的靶 DNA。使用碳二亚胺化学，将功能化的探针 DNA 链连接到基于羧基化葡聚糖的磁性颗粒上。随后与互补的靶 DNA 孵育会导致两条 DNA 链杂交时表面性质发生变化。通过电阻脉冲感应进行逐个颗粒分析以检测这些变化。可变压力方法允许识别颗粒表面电荷的变化。作为原理验证，我们证明了使用电阻脉冲感应可以选择性地在微摩尔浓度（纳摩尔靶标）下检测到靶标杂交，这一点通过荧光和相分析光散射等互补技术得到了证实。讨论了使用电阻脉冲感应进行样品分析的优点、可行性和局限性。
