Amplified Single Base-Pair Mismatch Detection via Aggregation of Exonuclease-Sheared Gold Nanoparticles

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• 作者：Shuo Wu ; Pingping Liang ; Haixiang Yu ; Xiaowen Xu ; Yuan Liu ; Xinhui Lou ; Yi Xiao
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：April 1, 2014
• 年：2014
• 卷：86
• 期：7
• 页码：3461-3467
• 全文大小：389K
• 年卷期：v.86,no.7(April 1, 2014)
• ISSN：1520-6882

文摘

Single nucleotide polymorphism (SNP) detection is important for early diagnosis, clinical prognostics, and disease prevention, and a rapid and sensitive low-cost SNP detection assay would be valuable for resource-limited clinical settings. We present a simple platform that enables sensitive, naked-eye detection of SNPs with minimal reagent and equipment requirements at room temperature within 15 min. SNP detection is performed in a single tube with one set of DNA probe-modified gold nanoparticles (AuNPs), a single exonuclease (Exo III), and the target in question. Exo III鈥檚 apurinic endonucleolytic activity differentially processes hybrid duplexes between the AuNP-bound probe and DNA targets that are perfectly matched or contain a single-base mismatch. For perfectly matched targets, Exo III鈥檚 exonuclease activity facilitates a process of target recycling that rapidly shears DNA probes from the particles, generating an AuNP aggregation-induced color change, whereas no such change occurs for mismatched targets. This color change is easily observed with as little as 2 nM of target, 100-fold lower than the target concentration required for reliable naked eye observation with unmodified AuNPs in well-optimized reaction conditions. We further demonstrate that this system can effectively discriminate a range of different mismatches.