title: Ultrasensitive thrombin detection based on direct electrochemistry of highly loaded hemoglobin spheres-encapsulated platinum nanoparticles as labels and electrocatalysts.
abstract: For the first time, a sandwich-type electrochemical method was proposed for ultrasensitive thrombin (TB) detection based on direct electrochemistry of highly loaded hemoglobin spheres-encapsulated platinum nanoparticles (PtNPs@Hb) as labels and electrocatalysts. The prepared PtNPs@Hb not only exhibited good biocompatibility, excellent electrocatalytic activity, but also presented redox activity of Hb. Thus, it was employed for the fabrication of aptasensor without any extraneous redox mediators, leading to a simple preparation process for the aptasensor. The high loading of Hb spheres as redox mediators could enhance the electrochemical signal. Importantly, the synergetic electrocatalytic behavior of Hb and PtNPs toward H2O2 reduction greatly amplified the electrochemical signal, resulting in the high sensitivity of aptasensor. Consequently, under optimal conditions, the designed aptasensor exhibited a lower detection limit of 0.05 pM and wide dynamic linear range from 0.15 pM to 40 nM for TB detection. Additionally, the proposed mediator-free and signal-amplified electrochemical aptasensor showed great potential in portable and cost-effective TB sensing devices.
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: Yongmei
authors.initials: Y
authors.lastname: Wu
authors.forename: Wenju
authors.initials: W
authors.lastname: Xu
authors.forename: Lijuan
authors.initials: L
authors.lastname: Bai
authors.forename: Yali
authors.initials: Y
authors.lastname: Yuan
authors.forename: Huayu
authors.initials: H
authors.lastname: Yi
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques; D002384:Catalysis; D055664:Electrochemical Techniques; D006454:Hemoglobins / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D008958:Models, Molecular; D053758:Nanoparticles / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D013917:Thrombin / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D006454:Hemoglobins; D010984:Platinum; D013917:Thrombin
keywords: Direct electrochemistry; Electrochemical aptasensor; Hemoglobin spheres; Sandwich-type; Thrombin