title: Application of Europium Multiwalled Carbon Nanotubes as Novel Luminophores in an Electrochemiluminescent Aptasensor for Thrombin Using Multiple Amplification Strategies.
abstract: A novel electrochemiluminescent (ECL) aptasensor was proposed for the determination of thrombin (TB) using exonuclease-catalyzed target recycling and hybridization chain reaction (HCR) to amplify the signal. The capture probe was immobilized on an Au-GS-modified electrode through a Au-S bond. Subsequently, the hybrid between the capture probe and the complementary thrombin binding aptamer (TBA) was aimed at obtaining double-stranded DNA (dsDNA). The interaction between TB and its aptamer led to the dissociation of dsDNA because TB has a higher affinity to TBA than the complementary strands. In the presence of exonuclease, aptamer was selectively digested and TB could be released for target recycling. Extended dsDNA was formed through HCR of the capture probe and two hairpin DNA strands (NH2-DNA1 and NH2-DNA1). Then, numerous europium multiwalled carbon nanotubes (Eu-MWCNTs) could be introduced through amidation reaction between NH2-terminated DNA strands and carboxyl groups on the Eu-MWCNTs, resulting in an increased ECL signal. The multiple amplification strategies, including the amplification of analyte recycling and HCR, and high ECL efficiency of Eu-MWCNTs lead to a wide linear range (1.0×10(-12)-5.0×10(-9) mol/L) and a low detection limit (0.23 pmol/L). The method was applied to serum sample analysis with satisfactory results.
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.affiliation: ‡National Engineering Technology Research Center for Colloidal Materials, Shandong University, Jinan 250100, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Xin
authors.forename: Xuehui
authors.initials: X
authors.lastname: Pang
authors.affiliation: §Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Pietraszkiewicz
authors.affiliation: §Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors.forename: Robert
authors.initials: R
authors.lastname: Hozyst
authors.forename: Xian'ge
authors.initials: X
authors.lastname: Sun
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D005063:Europium / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D016014:Linear Models; D049408:Luminescent Agents / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D015203:Reproducibility of Results; D013917:Thrombin / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D049408:Luminescent Agents; D037742:Nanotubes, Carbon; C081676:thrombin aptamer; D005063:Europium; D013917:Thrombin
keywords: Eu-MWCNTs; aptasensor; electrochemiluminescence; target recycling; thrombin