title: Electrochemical performance of gold nanoparticle-cytochrome c hybrid interface for H2O2 detection.
abstract: Here, we describe the formation of a hybrid biointerface consisting of gold nanoparticle (AuNP) and cytochrome c (cyt c) on indium tin oxide (ITO) electrodes using a two-step immobilization procedure. The Au nanoparticles were attached to the ITO electrodes by 3-mercaptopropyl trimethoxysilane (3-MPTMS). The electrode was then incubated with 11-mercapundecanoic acid (11-MUA) and the nanoparticles were activated to allow for coupling to cyt c. This process resulted in the formation of the AuNP/cyt c hybrid on the ITO electrode. The ITO/AuNP/cyt c substrate surfaces were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction analysis (XRD), and cyclic voltammetry (CV) techniques. Further analysis regarding the surface roughness properties of ITO, ITO/AuNP and ITO/AuNP/cyt c were also performed. The ITO/AuNP/cyt c immobilized ITO electrode displayed a pair of well-defined redox peaks (E(pa) at 0.09 V and E(pc) at 0.02 V) at pH 7.0 in HEPES buffer solution. Differential pulse voltammetry (DPV) and amperometric i-t measurements on the modified electrode showed a linear response after the addition of hydrogen peroxide (H(2)O(2)). The developed electrode sensor had an electron transfer rate constant (k(s)) of 0.69 s(-1) with a detection limit of 0.5 μM. The results of this study suggest that the hybrid layers were well fabricated on the ITO surface and the developed ITO/AuNP/cyt c electrode displayed an excellent electrocatalytic response for the detection of H(2)O(2).
authors.affiliation: Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul, Republic of Korea.
authors.forename: Ajay Kumar
authors.initials: AK
authors.lastname: Yagati
authors.forename: Taek
authors.initials: T
authors.lastname: Lee
authors.forename: Junhong
authors.initials: J
authors.lastname: Min
authors.forename: Jeong-Woo
authors.initials: JW
authors.lastname: Choi
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D002384:Catalysis; D045304:Cytochromes c / Q000378:metabolism*; D004560:Electricity; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D006736:Horses; D006861:Hydrogen Peroxide / Q000032:analysis*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D013997:Time Factors; D017971:Tin Compounds / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D017971:Tin Compounds; C109984:indium tin oxide; D006046:Gold; D045304:Cytochromes c; D006861:Hydrogen Peroxide