title: Amplified single base-pair mismatch detection via aggregation of exonuclease-sheared gold nanoparticles.
abstract: 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's 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's 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.
authors.affiliation: Department of Chemistry and Biochemistry, Florida International University , 11200 SW eighth Street, Miami, FL, 33199.
authors.forename: Shuo
authors.initials: S
authors.lastname: Wu
authors.forename: Pingping
authors.initials: P
authors.lastname: Liang
authors.forename: Haixiang
authors.initials: H
authors.lastname: Yu
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Xu
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Xinhui
authors.initials: X
authors.lastname: Lou
authors.forename: Yi
authors.initials: Y
authors.lastname: Xiao
mesh_terms: D020137:Base Pair Mismatch; D005092:Exonucleases / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles; D020641:Polymorphism, Single Nucleotide; D013056:Spectrophotometry, Ultraviolet
chemical_list: D006046:Gold; D005092:Exonucleases