title: An electrochemical molecular switch for one-step, reusable detection of a single-base mutation of DNA.
abstract: A new strategy for one-step, reusable and sensitive detection of a single-base mutation based on an electrochemical molecular switch is developed in the present work. When the hybridization reaction takes place in the presence of target DNA, the Fc-labeled terminal of the open switch molecule can be captured by the probe through the predesigned complementary bases of both sequences. By this method, a signal-on sensor featuring both generalizability and simplicity towards reagentless detection of DNA with sensitivity and selectivity electrochemical system is built on. The approach had been demonstrated with the identification of a single-base mutation of alpha-thalassemia point mutation in Hb Constant Spring codon 142 (TAA --> CAA). The wild-type and mutant-type of the synthetic 16 mer DNA sequences as the model targets were successfully discriminated. The results showed that the response signal was linear to the logarithm of the target concentration in the range from 0.01 to 100 pM with a detection limit of 0.01 pM. The regeneration experiment demonstrated that the sensor interface can be easily and successfully regenerated. All these revealed that the present system is a promising candidate for single-base mutation discrimination.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, Chemistry and Chemical Engineering College, Hunan University, Changsha 410082, PR China. jinxy588@sohu.com
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Jin
authors.forename: Yuehua
authors.initials: Y
authors.lastname: Fei
authors.forename: Liangliang
authors.initials: L
authors.lastname: Zhang
authors.forename: Xueping
authors.initials: X
authors.lastname: Liu
authors.forename: Guoli
authors.initials: G
authors.lastname: Shen
authors.forename: Ruqin
authors.initials: R
authors.lastname: Yu
mesh_terms: D004247:DNA / Q000032:analysis*; D004252:DNA Mutational Analysis; D055664:Electrochemical Techniques / Q000379:methods*; D006455:Hemoglobins, Abnormal / Q000235:genetics; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000737:chemistry; D017354:Point Mutation; D013997:Time Factors; D017085:alpha-Thalassemia / Q000235:genetics
chemical_list: D006455:Hemoglobins, Abnormal; D009841:Oligonucleotides; D004247:DNA; C035541:Hemoglobin Constant Spring