title: Aptamer-based highly sensitive electrochemical detection of thrombin via the amplification of graphene.
abstract: Herein, we successfully fabricated a highly sensitive label-free electrochemical aptasensor for thrombin based on the amplification of graphene (Gra). The excellent electrochemical probe of nickel hexacyanoferrate nanoparticles (NiHCFNPs) was introduced to form Nafion-Graphene-NiHCFNPs (Nf-Gra-NiHCFNPs) nanocomposites membrane on the gold electrode. The employment of graphene not only enhanced the surface area of the electrode with increased NiHCFNPs immobilization, but also improved the conductivity of the electrode, which further effectively improved the sensitivity of this proposed aptasensor. Subsequently, AuNPs layer was formed to immobilize the thrombin aptamer (TBA) and enhance the stability of the composite monolayer mentioned above. Then, thiol-modified TBA was assembled onto the AuNPs layer. Thereafter, hexanethiol (HT) was employed to block the possible remaining active sites. With the dual amplification of Gra and AuNPs, the resulting aptasensor exhibited good current response to target thrombin with a wide linear range extended from 1 pM to 80 nM (the detection limit was 0.3 pM). Additionally, the morphologies of bare Au substrate, nickel hexacyanoferrate nanoparticles (NiHCFNPs) and nanocomposites were successfully characterized by atomic force microscopy (AFM).
authors.affiliation: 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.forename: Liping
authors.initials: L
authors.lastname: Jiang
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: Lijuan
authors.initials: L
authors.lastname: Bai
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D018625:Microscopy, Atomic Force; D009532:Nickel / Q000737:chemistry; D013917:Thrombin / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D006046:Gold; D006108:Graphite; D009532:Nickel; D013917:Thrombin