title: A novel electrochemical aptasensor for highly sensitive detection of thrombin based on the autonomous assembly of hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme nanowires.
abstract: In this work, a new signal amplified strategy was constructed based on isothermal exponential amplification reaction (EXPAR) and hybridization chain reaction (HCR) generating the hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme (HRP-mimicking DNAzyme) nanowires as signal output component for the sensitive detection of thrombin (TB). We employed EXPAR's ultra-high amplification efficiency to produce a large amount of two hairpin helper DNAs within a minutes. And then the resultant two hairpin helper DNAs could autonomously assemble the hemin/G-quadruplex HRP-mimicking DNAzymes nanowires as the redox-active reporter units on the electrode surface via hybridization chain reaction (HCR). The hemin/G-quadruplex structures simultaneously served as electron transfer medium and electrocatalyst to amplify the signal in the presence of H2O2. Specifically, only when the EXPAR reaction process has occurred, the HCR could be achieved and the hemin/G-quadruplex complexes could be formed on the surface of an electrode to give a detectable signal. The proposed strategy combines the amplification power of the EXPAR, HCR, and the inherent high sensitivity of the electrochemical detection. With such design, the proposed assay showed a good linear relationship within the range of 0.1 pM-50 nM with a detection limit of 33 fM (defined as S/N=3) for TB.
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: xieshunbi@163.com.
authors.forename: Shunbi
authors.initials: S
authors.lastname: Xie
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: yaqinchai@swu.edu.cn.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Bai
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: yuanruo@swu.edu.cn.
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
mesh_terms: D052157:Aptamers, Nucleotide / Q000032:analysis; D015374:Biosensing Techniques; D021881:DNA, Catalytic / Q000737:chemistry / Q000378:metabolism*; D055664:Electrochemical Techniques; D006427:Hemin / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism*; D053770:Nanowires / Q000737:chemistry; D013917:Thrombin / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D021881:DNA, Catalytic; D006427:Hemin; D006735:Horseradish Peroxidase; D013917:Thrombin
keywords: Electrochemical aptasensor; Exponential isothermal amplification; Hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme; Hybridization chain reaction; Thrombin