Au-nanoparticles as an electrochemical sensing platform for aptamer-thrombin interaction.
A novel electrochemical method for the detection of bioaffinity interactions based on a gold-nanoparticles sensing platform and on the usage of stripping voltammetry technique was developed. The oxidation of gold surface (resulted in gold oxide formation) upon polarization served as a basis for analytical response. As a model, thrombin-thrombin binding aptamer couple was chosen. The aptamer was immobilized on a screen-printed electrode modified with gold-nanoparticles by avidin-biotin technology. Cathodic peak area was found proportional to thrombin quantity specifically adsorbed onto electrode surface. Sigmoid calibration curve as is typical for immunoassay was obtained, with thrombin detection limit of 10(-9)M. Linear range corresponds from 10(-8) to 10(-5)M thrombin concentration or 2 x 10(-14) to 2 x 10(-11)mol/electrode (R=0.996). Binding of thrombin to an aptamer has also been detected using the ferricyanide/ferrocyanide redox couple as electrochemical indicator.
Suprun
Elena
E
Institute of Biomedical Chemistry, Russian Academy of Medical Sciences, Pogodinskaya Street 10, Moscow 119121, Russia.
Shumyantseva
Victoria
V
Bulko
Tatiana
T
Rachmetova
Svetlana
S
Rad'ko
Sergei
S
Bodoev
Nikolay
N
Archakov
Alexander
A