Electrochemical analysis of gold-coated magnetic nanoparticles for detecting immunological interaction
An electrochemical impedance immunosensor was developed for detecting the immunological interaction between human immunoglobulin (IgG) and protein A from Staphylococcus aureus based on the immobilization of human IgG on the surface of modified gold-coated magnetic nanoparticles. The nanoparticles with an Au shell and Fe oxide cores were functionalized by a self-assembled monolayer of 11-mercaptoundecanoic acid. The electrochemical analysis was conducted on the modified magnetic carbon paste electrodes with the nanoparticles. The magnetic nanoparticles were attached to the surface of the magnetic carbon paste electrodes via magnetic force. The cyclic voltammetry technique and electrochemical impedance spectroscopy measurements of the magnetic carbon paste electrodes coated with magnetic nanoparticles–human IgG complex showed changes in its alternating current (AC) response both after the modification of the surface of the electrode and the addition of protein A. The immunological interaction between human IgG on the surface of the modified magnetic carbon paste electrodes and protein A in the solution could be successfully monitored.
KeywordsGold-coated magnetic nanoparticles Electrochemical impedance spectroscopy Cyclic voltammetry Immunological interaction Nanomedicine
- Bouafsoun A, Helali S, Mebarek S, Zeiller C, Prigent AF, Othmane A, Kerkeni A, Jaffrezic-Renault N, Ponsonnet L (2007) Electrical probing of endothelial cell behaviour on a fibronectin/polystyrene/thiol/gold electrode by Faradaic electrochemical impedance spectroscopy (EIS). Bioelectrochemistry 70:401–407. doi:10.1016/j.bioelechem.2006.05.012 CrossRefPubMedGoogle Scholar
- Cao C, Sim SJ (2007) Signal enhancement of surface plasmon resonance immunoassay using enzyme precipitation-functionalized gold nanoparticles: a femto molar level measurement of anti-glutamic acid decarboxylase antibody. Biosens Bioelectron 22:1874–1880. doi:10.1016/j.bios.2006.07.021 CrossRefPubMedGoogle Scholar
- Jie M, Ming CY, Jing D, Cheng LS, Na LH, Jun F, Xiang CY (1999) An electrochemical impedance immunoanalytical method for detecting immunological interaction of human mammary tumor associated glycoprotein and its monoclonal antibody. Electrochem Commun 1:425–428. doi:10.1016/S1388-2481(99)00071-5 CrossRefGoogle Scholar
- Tang D, Yaun R, Chai Y, Fu Y, Dai J, Liu Y, Zhong X (2005) New amperometric and potentiometric immunosensors based on gold nanoparticles/tris(2,2′-bipyridyl)cobalt(III) multilayer films for hepatitis B surface antigen determinations. Biosens Bioelectron 21:539–546. doi:10.1016/j.bios.2004.11.024 CrossRefPubMedGoogle Scholar
- Zhou Y, Yuan R, Chai Y, Zhang Y, Li X, Wang N, Zhu Q (2006) Amperometric enzyme immunosensors based on layer-by-layer assembly of gold nanoparticles and thionine on Nafion modified electrode surface for α-1-fetoprotein determinations. Sens Actuators B 114:631–639. doi:10.1016/j.snb.2005.04.051 CrossRefGoogle Scholar