title: A pseudo triple-enzyme electrochemical aptasensor based on the amplification of Pt-Pd nanowires and hemin/G-quadruplex.
abstract: Our present work aimed at developing a pseudo triple-enzyme cascade electrocatalytic electrochemical aptasensor for determination of thrombin with the amplification of alcohol dehydrogenase (ADH)-Pt-Pd nanowires bionanocomposite and hemin/G-quadruplex structure that simultaneously acted as NADH oxidase and HRP-mimicking DNAzyme. With the addition of ethanol to the electrolyte, the ADH immobilized on the Pt-Pd nanowires catalyzed ethanol to acetaldehyde accompanied by NAD(+) being converted to NADH. Then the hemin/G-quadruplex firstly served as NADH oxidase, converting the produced NADH to NAD(+) with the concomitant local formation of high concentration of H2O2. Subsequently, the hemin/G-quadruplex acted as HRP-mimicking DNAzyme, bioelectrocatalyzing the produced H2O2. At the same time, the Pt-Pd nanowires employed in our strategy not only provided a large surface area for immobilizing thrombin binding aptamer (TBA) and ADH, but also served as HRP-mimicking DNAzyme which rapidly bioelectrocatalyzed the reduction of the produced H2O2. Thus, such a pseudo triple-enzyme cascade electrochemical aptasensor could greatly promote the electron transfer of hemin and resulted in the dramatic enhancement of electrochemical signal. As a result, a wide dynamic concentration linear range from 0.2 pM to 20 nM with a low detection limit of 0.067 pM for thrombin (TB) determination was obtained. The excellent performance indicated that our strategy was a promising way for ultrasensitive assays in electrochemical aptasensors.
authors.affiliation: Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Yingning
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: yqchai@swu.edu.cn.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.affiliation: Key Laboratory on Luminescence and Real-Time Analysis, 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 on Luminescence and Real-Time Analysis, 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: D000426:Alcohol Dehydrogenase / Q000378:metabolism; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D021881:DNA, Catalytic / Q000378:metabolism; D055664:Electrochemical Techniques / Q000295:instrumentation; D004867:Equipment Design; D054856:G-Quadruplexes; D006427:Hemin / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D009097:Multienzyme Complexes / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D010165:Palladium / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D013917:Thrombin / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D021881:DNA, Catalytic; D009097:Multienzyme Complexes; C081676:thrombin aptamer; D010984:Platinum; D010165:Palladium; D006427:Hemin; D000426:Alcohol Dehydrogenase; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D013917:Thrombin
keywords: Aptasensor; Hemin/G-quadruplex; Pt–Pd nanowires; Thrombin; Triple-enzyme cascade electrocatalytic