title: Label-free electrochemical detection of human α-thrombin in blood serum using ferrocene-coated gold nanoparticles.
abstract: This paper describes a novel approach to label-free electrochemical detection of human α-thrombin in human blood serum that utilizes ferrocene-coated gold nanoparticles (Fc-AuNPs). Human α-thrombin was specifically bound by the thiolated aptamers immobilized on the electrode. Positively charged Fc-AuNPs were electrostatically bound to the negatively charged aptamers. In principle, a high current peak should be observed in the absence of interactions between the aptamers and the human α-thrombin. This behavior indicates maximum adsorption of Fc-AuNPs by the negatively charged aptamers on the electrode surface. In contrast, when the thrombin-aptamer complex is formed, a low signal is expected because of the blocking capacities of the protein, which hinders the electrostatic binding of the Fc-AuNPs. The electrochemical signal, recorded by cyclic voltammetry and differential pulse voltammetry, indicates whether interactions between aptamers and proteins have occurred. There is a good correlation between the ferrocene oxidation peak intensity readings from our thrombin sensing system and the thrombin concentration, within the range of 1.2 μM-12 pM.
authors.affiliation: BioNanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea.
authors.forename: Dohyoung
authors.initials: D
authors.lastname: Kwon
authors.forename: Hyunkyung
authors.initials: H
authors.lastname: Jeong
authors.forename: Bong Hyun
authors.initials: BH
authors.lastname: Chung
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D005296:Ferrous Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D000075163:Metallocenes; D013917:Thrombin / Q000032:analysis* / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D005296:Ferrous Compounds; D000075163:Metallocenes; D006046:Gold; D013917:Thrombin; C004998:ferrocene