title: Nanocomposites of gold nanoparticles and graphene oxide towards an stable label-free electrochemical immunosensor for detection of cardiac marker troponin-I.
abstract: A stable label-free amperometric immunosensor is presented based on gold nanoparticles and graphene oxide nanocomposites for detection of cardiac troponin-I in the early diagnosis of myocardial infarction. For designing of the sensing platform, firstly the nanocomposites based on GO and AuNPs were prepared and anchored on electrode surfaces. The formed nanocomposites provided a platform with big surface area for loading anti-cTnI capture antibody, and worked as a bridge for fast electron transfer subsequently increased the sensitivity. Moreover, the linkages between AuNP, GO, and electrodes were based on covalent bonding by aryldiazonium salt coupling chemistry, which favors the stability of the sensing interface. Finally, the anti-cTnI detection antibody was immobilized on GO tailored with ferrocene molecules, functioning as the signal reporter for the detection of cTnI. The modification process was monitored using electrochemistry, SEM, XPS. The herein immunosensor demonstrates a good selectivity and high sensitivity against human-cTnI, and is capable of detecting cTnI at concentrations as low as 0.05 ng mL(-1), which is 100 times lower than that possible by conventional methods. It is potential to design the portable sensing platform based on AuNPs and GO nanocomposites for future point-of-care diagnostics.
authors: Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China; ARC Centre of Excellence in Nanoscale Biophotonics (CNBP), Department of Physics and Astronomy, Macquarie University, North Ryde 2109, Australia. Electronic address: gzliu@mail.ccnu.edu.cn.
authors: Guozhen
authors: G
authors: Liu
authors: Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
authors: Meng
authors: M
authors: Qi
authors: Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
authors: Yin
authors: Y
authors: Zhang
authors: Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
authors: Chaomin
authors: C
authors: Cao
authors: ARC Centre of Excellence in Nanoscale Biophotonics (CNBP), Department of Physics and Astronomy, Macquarie University, North Ryde 2109, Australia.
authors: Ewa M
authors: EM
authors: Goldys
mesh_terms: D015415:Biomarkers / Q000032:analysis; D055664:Electrochemical Techniques; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006331:Heart Diseases / Q000175:diagnosis; D006801:Humans; D007118:Immunoassay; D053768:Metal Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties; D019210:Troponin I / Q000032:analysis*
chemical_list: D015415:Biomarkers; D010087:Oxides; D019210:Troponin I; D006046:Gold; D006108:Graphite
keywords: AuNPs; Ferrocene; Graphene oxides; Immunosensors; Troponin-I