Abstract
Gold nanoparticles (GNPs) have been electrodeposited on indium tin oxide (ITO) and applied to detect molecular interaction between antigen and antibody by measuring open circuit potential (OCP). As a capture protein for immunoassay, specific monoclonal antibody against human cardiac troponin I (cTnI) was modified on the GNP coated ITO electrode surface by self-assembly and characterized by electrochemical techniques. This is a simple, stable, and repeatable approach. The modified electrode can be used to detect human cTnI. In this study, we adopted a new strategy to get an electrical signal due to the enzyme-based immunecatalytic reaction by measuring the changes of OCP. This novel approach can be applied to a simplified and miniaturized diagnostic system. A linear dependence of OCP changes according to cTnI concentrations is observed in the range of concentration from 1 to 100 ng/ml. Because the clinical borderline of cTnI between normal and patient is 0.5 to 2.0 ng/ml, our results indicate that the new approach using OCP changes has a great potential for clinical diagnostic application.
Original language | English |
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Pages (from-to) | 1906-1916 |
Number of pages | 11 |
Journal | International Journal of Electrochemical Science |
Volume | 6 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2011 |
Keywords
- Biosensor
- Cardiac troponin
- Gold nanoparticles
- ITO electrode
- Open circuit potential