title: An ultrasensitive electrochemical aptasensor for thrombin based on the triplex-amplification of hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme and horseradish peroxidase decorated FeTe nanorods.
abstract: In the present study, we fabricated an ultrasensitive sandwich-type electrochemical aptasensor for thrombin (TB) based on a triplex signal amplification strategy. The hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme (HRP-DNAzyme) as well as blocking reagent-horseradish peroxidase (HRP) and iron telluride nanorods (FeTe NRs) could simultaneously amplify the electrochemical signal of thionine (Thi) in the presence of H(2)O(2). Herein, FeTe NRs, as a newly discovered HRP-mimicking enzyme, were employed to construct an aptasensor for the first time. And, the FeTe NRs decorated by gold nanoparticles (abbreviated as AuNPs@FeTe NRs), were not only used as carriers of secondary thrombin aptamer (TBA 2), electron mediator thionine (Thi) and HRP, but also catalyzed the electrochemical reaction of Thi in the presence of H(2)O(2). As can be seen from experiment results, with the triplex signal amplification strategy, the reduction peak current of the fabricated aptasensor was logarithmically related to the concentration of thrombin (TB) over a wide range from 1 pM to 20 nM, and a detection limit of 0.5 pM was obtained. Hence, the proposed aptamer-based sandwich sensing approach for amplified detection of TB could provide a promising way for highly sensitive determination of other analytes.
authors: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, People's Republic of China.
authors: Liping
authors: L
authors: Jiang
authors: Ruo
authors: R
authors: Yuan
authors: Yaqin
authors: Y
authors: Chai
authors: Yali
authors: Y
authors: Yuan
authors: Lijuan
authors: L
authors: Bai
authors: Yan
authors: Y
authors: Wang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D021881:DNA, Catalytic / Q000737:chemistry; D055664:Electrochemical Techniques / Q000379:methods*; D004800:Enzymes, Immobilized / Q000737:chemistry; D054856:G-Quadruplexes; D006046:Gold / Q000737:chemistry; D006427:Hemin / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry; D006801:Humans; D058085:Iron Compounds / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D013691:Tellurium / Q000737:chemistry*; D013917:Thrombin / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D021881:DNA, Catalytic; D004800:Enzymes, Immobilized; D058085:Iron Compounds; C081676:thrombin aptamer; D006427:Hemin; D006046:Gold; D006735:Horseradish Peroxidase; D013917:Thrombin; D013691:Tellurium