title: Platinum-gold alloy nanoparticles and horseradish peroxidase functionalized nanocomposite as a trace label for ultrasensitive electrochemical detection of thrombin.
abstract: A novel tracer, platinum-gold alloy nanoparticles (Pt-AuNPs) and horseradish peroxidase (HRP) functionalized single-walled carbon nanotubes (SWCNTs) composite, is employed to label the secondary thrombin aptamer for constructing an ultrasensitive electrochemical aptasensor. Thionine, immobilized on functionalized SWCNTs, provides a pair of distinguished redox peak for electrochemical detection. Both the high-content Pt-AuNPs and HRP on SWCNTs amplify the electrochemical signal of thionine through electrocatalytic reduction of H(2)O(2). Differential pulse voltammetry (DPV) is employed to detect thrombin with different concentrations. The reduction peak current is logarithmically related to the concentration of thrombin in an extremely wide range from 10 fM to 5 nM with a detection limit of 3.6 fM. The dual signal amplification of Pt-AuNPs and HRP functionalized nanocomposite provides a promising way for ultrasensitive assay in electrochemical aptasensors.
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, People's Republic of China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Bai
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.forename: Yali
authors.initials: Y
authors.lastname: Yuan
authors.forename: Li
authors.initials: L
authors.lastname: Mao
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000497:Alloys / Q000737:chemistry; D052157:Aptamers, Nucleotide / Q000032:analysis / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004563:Electrochemistry; D006046:Gold / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry* / Q000378:metabolism; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D037742:Nanotubes, Carbon; D010984:Platinum / Q000737:chemistry; D015203:Reproducibility of Results; D013917:Thrombin / Q000032:analysis* / Q000737:chemistry
chemical_list: D000497:Alloys; D052157:Aptamers, Nucleotide; D037742:Nanotubes, Carbon; C081676:thrombin aptamer; D010984:Platinum; D006046:Gold; D006735:Horseradish Peroxidase; D013917:Thrombin