title: Gold-based optical biosensor for single-mismatched DNA detection using salt-induced hybridization.
abstract: 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.
authors.affiliation: Department of Chemical Engineering, Sungkyunkwan University, Suwon 440-746, South Korea.
authors.forename: Zongrui
authors.initials: Z
authors.lastname: Zhan
authors.forename: Xingyi
authors.initials: X
authors.lastname: Ma
authors.forename: Cuong
authors.initials: C
authors.lastname: Cao
authors.forename: Sang Jun
authors.initials: SJ
authors.lastname: Sim
mesh_terms: D020137:Base Pair Mismatch; D001483:Base Sequence; D004247:DNA / Q000032:analysis / Q000235:genetics*; D019398:Genes, BRCA1; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009693:Nucleic Acid Hybridization / Q000379:methods*; D012492:Salts / Q000737:chemistry; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D012492:Salts; D006046:Gold; D004247:DNA