Polymer Electronics Research Centre, University of Auckland, Private Bag-92019, Auckland, New Zealand.
Biosens Bioelectron. 2011 Oct 15;28(1):362-7. doi: 10.1016/j.bios.2011.07.051. Epub 2011 Jul 26.
DNA sensors have a wide scope of applications in the present and emerging medical and scientific fields, such as medical diagnostics and forensic investigations. However, much research-to-date on DNA sensor development has focused on short target DNA strands as model genes. In this communication we study the effect of the length of oligonucleotide probe and target strands as a significant step towards real world applications for DNA detection. The sensor technology described uses the conducting polymer polypyrrole as both a sensing element and transducer of sensing events - namely the hybridization of complementary target oligonucleotide to probe oligonucleotide. Detection is performed using electrical impedance spectroscopy. Initially sensor development is performed, wherein we demonstrate an improvement in stability and sensitivity as well as show a reduction in non-specific DNA binding for fabricated sensors, through use of a specific dopant and post-growth treatment. Subsequently, we show that longer target DNA strands display increased response, as do sensors containing longer probe DNA strands. It is suggested that these results are a feature of the increase in negative charges associated with the longer DNA strands. The results of this comparative study are aimed to guide future design of analogous sensors.
DNA 传感器在当前和新兴的医学和科学领域有广泛的应用，例如医学诊断和法医学调查。然而，迄今为止，许多关于 DNA 传感器开发的研究都集中在短的靶 DNA 链作为模型基因上。在本通讯中，我们研究了寡核苷酸探针和靶链长度的影响，这是 DNA 检测在实际应用中的重要一步。所描述的传感器技术使用导电聚合物聚吡咯作为传感元件和传感事件的换能器——即互补靶寡核苷酸与探针寡核苷酸的杂交。使用阻抗谱进行检测。最初进行传感器的开发，我们通过使用特定的掺杂剂和后生长处理，证明了制造的传感器的稳定性和灵敏度的提高，以及非特异性 DNA 结合的减少。随后，我们表明，较长的靶 DNA 链显示出增加的响应，而含有较长探针 DNA 链的传感器也是如此。有人认为，这些结果是与较长 DNA 链相关的负电荷增加的特征。这项比较研究的结果旨在为类似传感器的未来设计提供指导。
