Gold and Silver Nanoparticles for Electrochemical Detection of Cardiac Troponin I Based on Stripping Voltammetry

A novel electrochemicalmethod for the detection of cardiac troponin I (cTnI) based on stripping voltammetry of gold or silver nanoparticles was developed. The analytical response was a gold oxides reduction peak current after 30 s oxidation E=+1.2Vor peak current after the oxidation of silver upon polarization. Cathodic peak height of Au and anodic peak height of Ag were found to be proportional to the quantity of cTnI specifically adsorbed onto the electrode surface modified with anti-cTnI. The monitoring of cTnI was performed using plasma samples of healthy donors and patients with acute myocardial infarction. The limit of detection of screen-printed electrode/AuNPel/didodecyldimethylammonium bromide/anti-cTnI was equal to 0.1 ng/ml (4.25 pM). Linear range of cTnI response corresponded to the 0.1-32 ng/ml (4.25 pM-1.34 nM) concentration range with a correlation coefficient of 0.97.