Department of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, South Korea.
Biosens Bioelectron. 2012 Feb 15;32(1):127-32. doi: 10.1016/j.bios.2011.11.045. Epub 2011 Dec 6.
In this study, a gold nanoparticle (Au-NP)-based detection method for sensitive and specific DNA-based diagnostic applications is described. A sandwich format consisting of Au-NPs/DNA/PMP (Streptavidin-coated MagnetSphere Para-Magnetic Particles) was fabricated. PMPs captured and separated target DNA while Au-NPs modified with oligonucleotide detection sequences played a role in recognition and signal production. Due to the much lower stability of mismatched DNA strands caused by unstable duplex structures in solutions of relatively low salt concentration, hybridization efficiency in the presence of different buffers was well investigated, and thus, the optimized salt concentration allowed for discrimination of single-mismatched DNA (MMT) from perfectly matched DNA (PMT). Therefore, quantitative information concerning the target analyte was translated into a colorimetric signal, which could easily and quantitatively measured by low-cost UV-vis spectrophotometric analysis. The results indicated this to be a very simple and economic strategy for detection of single-mismatched DNA strands.
在这项研究中，描述了一种基于金纳米粒子（Au-NP）的检测方法，用于敏感和特异性的基于 DNA 的诊断应用。制备了一种由 Au-NPs/DNA/PMP（链霉亲和素包被的磁珠）组成的三明治结构。PMP 捕获并分离靶 DNA，而修饰有寡核苷酸检测序列的 Au-NPs 则在识别和信号产生中发挥作用。由于在相对低盐浓度的溶液中，由于不稳定的双链结构，错配 DNA 链的稳定性要低得多，因此很好地研究了不同缓冲液存在下的杂交效率，并且优化了盐浓度，从而能够区分单错配 DNA（MMT）和完全匹配 DNA（PMT）。因此，可以将有关目标分析物的定量信息转化为比色信号，并且可以通过低成本的紫外可见分光光度分析轻松且定量地测量该信号。结果表明，这是一种用于检测单链错配 DNA 的非常简单和经济的策略。
