title: Ligase chain reaction amplification for sensitive electrochemiluminescent detection of single nucleotide polymorphisms.
abstract: Single nucleotide polymorphisms are the most common type of genetic variations among human beings and can serve as biomarkers for various types of diseases. In this work, based on ligase chain reaction amplification for the production of massive hemin/G-quadruplex DNAzymes to quench the electrochemiluminescent (ECL) emission of quantum dots (QDs), a universal and sensitive single nucleotide polymorphism detection method is described. During the ligase chain reaction process, the mutant K-ras target gene is recycled and exponentially duplicated, leading to the attachment of numerous G-rich sequences on the QD-embedded sensing surface. Upon the addition of the assistant sequences and hemin, numerous hemin/G-quadruplex DNAzymes are formed, which consume the dissolved oxygen in the detection buffer and result in significant quenching of QD ECL emission for sensitive single nucleotide polymorphism determination. The developed method shows a linear range of 50 fM to 50 pM and an estimated detection limit of 45 fM for the mutant K-ras gene. The proposed strategy also exhibits high selectivity towards the mutant K-ras gene against the co-existence of 10(3)-fold excess of the wild-type K-ras gene, which makes our method a useful addition to the alternatives for single nucleotide polymorphism monitoring.
authors.affiliation: Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Mengli
authors.initials: M
authors.lastname: Yang
authors.forename: Yun
authors.initials: Y
authors.lastname: Xiang
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
mesh_terms: D021881:DNA, Catalytic / Q000737:chemistry; D054856:G-Quadruplexes; D011905:Genes, ras; D006427:Hemin / Q000737:chemistry; D006801:Humans; D022521:Ligase Chain Reaction / Q000379:methods*; D008163:Luminescent Measurements; D020641:Polymorphism, Single Nucleotide; D045663:Quantum Dots; D012680:Sensitivity and Specificity
chemical_list: D021881:DNA, Catalytic; D006427:Hemin
keywords: DNA; Electrochemiluminescence; Ligase chain reaction; Quantum dots; Single nucleotide polymorphisms