title: Surface characterization of immunosensor conjugated with gold nanoparticles based on cyclic voltammetry and X-ray photoelectron spectroscopy.
abstract: This investigation describes the surface characterization of rabbit immunoglobulin G (IgG) conjugated with gold nanoparticles. Goat anti-rabbit immunoglobulin G tagged with 5nm gold nanoparticles was applied to detect the IgG. Then, the autocatalyzed deposition of Au(3+) onto the surface of anti-IgGAu increased the surface area per gold nanoparticle. The immobilization chemistries and the atomic concentrations of Au(4f), P(2p), S(2p), C(1s), N(1s) and O(1s) of the resulting antibody-modified Au electrodes were determined by X-ray photoelectron spectroscopy (XPS). The sulfur that is involved in the cysteamine binding and the enlargement of the gold nanoparticles are identified using cyclic voltammetry. The results reveal that the surface area per gold particle, following the autocatalyzed deposition Au(3+) on the surface of anti-IgGAu, was approximately seven times higher than that before deposition.
authors.affiliation: National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan, ROC. jene@nsrrc.org.tw
authors.forename: Lee-Jene
authors.initials: LJ
authors.lastname: Lai
authors.forename: Yaw-Wen
authors.initials: YW
authors.lastname: Yang
authors.forename: Yao-Kwang
authors.initials: YK
authors.lastname: Lin
authors.forename: Li-Ling
authors.initials: LL
authors.lastname: Huang
authors.forename: Yi-Heui
authors.initials: YH
authors.lastname: Hsieh
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D002244:Carbon / Q000032:analysis; D003543:Cysteamine / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay; D007074:Immunoglobulin G / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D009584:Nitrogen / Q000032:analysis; D010100:Oxygen / Q000032:analysis; D011817:Rabbits; D012996:Solutions; D013057:Spectrum Analysis / Q000379:methods*; D013499:Surface Properties; D013696:Temperature
chemical_list: D007074:Immunoglobulin G; D012996:Solutions; D003543:Cysteamine; D002244:Carbon; D006046:Gold; D009584:Nitrogen; D010100:Oxygen