CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology of China, Beijing 100190, China.
Anal Chem. 2012 Feb 7;84(3):1253-8. doi: 10.1021/ac201713t. Epub 2012 Jan 20.
We developed a novel strategy for rapid colorimetric analysis of a specific DNA sequence by combining gold nanoparticles (AuNPs) with an asymmetric polymerase chain reaction (As-PCR). In the presence of the correct DNA template, the bound oligonucleotides on the surface of AuNPs selectively hybridized to form complementary sequences of single-stranded DNA (ssDNA) target generated from As-PCR. DNA hybridization resulted in self-assembly and aggregation of AuNPs, and a concomitant color change from ruby red to blue-purple occurred. This approach is simpler than previous methods, as it requires a simple mixture of the asymmetric PCR product with gold colloid conjugates. Thus, it is a convenient colorimetric method for specific nucleic acid sequence analysis with high specificity and sensitivity. Most importantly, the marked color change occurs at a picogram detection level after standing for several minutes at room temperature. Linear amplification minimizes the potential risk of PCR product cross-contamination. The efficiency to detect Bacillus anthracis in clinical samples clearly indicates the practical applicability of this approach.
我们开发了一种新的策略，通过将金纳米粒子（AuNPs）与不对称聚合酶链反应（As-PCR）结合，实现对特定 DNA 序列的快速比色分析。在存在正确的 DNA 模板的情况下，AuNPs 表面结合的寡核苷酸选择性杂交，形成来自 As-PCR 的单链 DNA（ssDNA）目标的互补序列。DNA 杂交导致 AuNPs 的自组装和聚集，并且发生从红宝石红到蓝紫色的伴随颜色变化。与以前的方法相比，这种方法更简单，因为它只需要将不对称 PCR 产物与金胶体缀合物简单混合即可。因此，它是一种用于特定核酸序列分析的方便的比色方法，具有高特异性和灵敏度。最重要的是，在室温下静置几分钟后，即可在皮克检测水平上观察到明显的颜色变化。线性扩增最小化了 PCR 产物交叉污染的潜在风险。在临床样本中检测炭疽杆菌的效率清楚地表明了这种方法的实际适用性。
