title: Electrochemical biosensors for detection of point mutation based on surface ligation reaction and oligonucleotides modified gold nanoparticles.
abstract: An electrochemical method for point mutation detection based on surface ligation reaction and oligonucleotides (ODNs) modified gold nanoparticles (AuNPs) was demonstrated. Point mutation identification was achieved using Escherichia coli DNA ligase. This system for point mutation detection relied on a sandwich assay comprising capture ODN immobilized on Au electrodes, target ODN and ligation ODN. Because of the sequence-specific surface reactions of E. coli DNA ligase, the ligation ODN covalently linked to the capture ODN only in the presence of a perfectly complementary target ODN. The presence of ligation products on Au electrode was detected using chronocoulometry through hybridization with reporter ODN modified AuNPs. The use of AuNPs improved the sensitivity of chronocoulometry in this approach, a detection limit of 0.9 pM complementary ODN was obtained. For single base mismatched ODN (smODN), a negligible signal was observed. Even if the concentration ratio of complementary ODN to smODN was decreased to 1:1000, a detectable signal was observed. This work may provide a specific, sensitive and cost-efficient approach for point mutant detection.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.forename: Lijuan
authors.initials: L
authors.lastname: Yang
authors.forename: Xiaohai
authors.initials: X
authors.lastname: Yang
authors.forename: Kemin
authors.initials: K
authors.lastname: Wang
authors.forename: Leiliang
authors.initials: L
authors.lastname: He
authors.forename: Jinqing
authors.initials: J
authors.lastname: Zhu
mesh_terms: D020137:Base Pair Mismatch; D015374:Biosensing Techniques / Q000379:methods*; D011088:DNA Ligases / Q000737:chemistry; D004252:DNA Mutational Analysis / Q000379:methods*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry; D009841:Oligonucleotides / Q000737:chemistry; D017354:Point Mutation; D012680:Sensitivity and Specificity
chemical_list: D009841:Oligonucleotides; D006046:Gold; D011088:DNA Ligases