Non-enzymatic detection of Cardiac Troponin − I using polyethylene imine-stabilized fluorescent gold nanoclusters

Abstract

Despite the very high specificity and simplicity, antibody-based assays require high costs and top-end preservation facilities to develop an efficient biosensor. We constructed “An antibody-free fluorescence probe for cardiac troponin -I,” the ‘gold standard’ marker for diagnosing myocardial infarction. In the present work, positively charged green-emitting gold nanoclusters were synthesized through a one-pot microwave-mediated method, and the fluorescence response with heparin was studied. These heparin-conjugated gold nanoclusters were further utilized as a fluorescence probe for the non-enzymatic detection of cardiac troponin I. The linear detection of troponin with a low limit of detection of 0.1631 ng/mL was achieved with the probe. The challenging interfering perturbation of the co-existing biomolecules was evaluated, among which only glutathione showed an insignificant turn-on response within the biological limit.