title: In situ hybridization chain reaction mediated ultrasensitive enzyme-free and conjugation-free electrochemcial genosensor for BRCA-1 gene in complex matrices.
abstract: In this study, we report an enzyme-free and conjugation-free electrochemical genosensor enabling an ultrasensitive readout of BRCA-1, a breast cancer susceptibility gene. The sensor employs a target-responsive hybridization chain reaction (HCR) to significantly amplify the detectable current signals. By means of a functional auxiliary probe pair and a versatile initiator sequence, a linear DNA concatemer structure can be formed via spontaneous and continuous polymerization of DNA oligomers in the presence of target sequence. Such a DNA nanoassembly endows the genosensor an ultrahigh sensitivity up to 1 aM, which is higher than that of the nanomaterials-based or enzyme mediated amplification approaches by several orders of magnitude. More importantly, the sensor's responsive peak current exhibits a favorable linear correlation to the logarithm of the concentrations of target sequence ranging from 1 aM to 10 pM. In addition, the sensor is highly selective, and can discriminate a single mismatched sequence. This HCR-based genosensor is also capable of probing low-abundance BRCA-1 gene sequence directly in complex matrices, such as 50% human serum, with minimal interference. These advantages will make our tailor-engineered HCR-based electrochemical genosensor appealing to genetic analysis and clinical diagnostics.
authors.affiliation: Medical College, Henan University of Science and Technology, Luoyang 471003, China. Electronic address: yanghui@haust.edu.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Yang
authors.affiliation: Medical College, Henan University of Science and Technology, Luoyang 471003, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.affiliation: School of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan 430065, China.
authors.forename: Siqi
authors.initials: S
authors.lastname: Wang
authors.affiliation: Cancer Center of Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
authors.forename: You
authors.initials: Y
authors.lastname: Qin
authors.affiliation: School of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan 430065, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Xu
authors.affiliation: School of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan 430065, China. Electronic address: jimyin_126@126.com.
authors.forename: Dan
authors.initials: D
authors.lastname: Jin
authors.affiliation: School of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan 430065, China. Electronic address: yangf2013@hbtcm.edu.cn.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
authors.affiliation: School of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan 430065, China.
authors.forename: Guo-Jun
authors.initials: GJ
authors.lastname: Zhang
mesh_terms: D019313:BRCA1 Protein / Q000097:blood* / Q000235:genetics / Q000302:isolation & purification*; D015374:Biosensing Techniques; D001943:Breast Neoplasms / Q000097:blood* / Q000235:genetics; D005260:Female; D006801:Humans; D017403:In Situ Hybridization
chemical_list: D019313:BRCA1 Protein
keywords: BRCA-1 gene; Electrochemistry; Genosensor; Hybridization chain reaction; Signal amplification