Dendrimer-encapsulated nanoparticles as a sensing platform for Alzheimer´s biomarker detection

Abstract

The Alzheimer's disease (AD) is a chronic neurodegenerative disease. Early diagnosis is extremely necessary and desirable, as it allows access to therapies that alleviate the symptoms from the disease onset. The Tau protein is one of biomarkers for AD and may be detected in human serum to estimate the risk or presence of AD. Currently, methods for the detection of biomarker do not exhibit high sensitivity for diagnosis in early stages and costs are incompatible with the wide monitoring required. Thus, this project proposes the development and optimization of an electrochemical immunosensor (EI) based on the modification of screen printed electrodes with carbon nanotubes or reduced graphene oxide and dendrimer-encapsulated gold nanoparticles. Subsequently, the modified electrodes will be characterized by various techniques. The modification of surface electrode may significantly improve the electrochemical detection (ED) properties of EI developed by decreasing the electrode overpotential and increasing the current intensity and/or increased sensitivity. The antibodies are linked to nanostructures on the electrode surface through the formation of bonds using EDC/NHS. The biomarkers electrochemical detection occurs using an antibody labeled with the enzyme horseradish peroxidase (HRP). In the ED system, hydroquinone (HQ) is added to detection solution as an electronic mediator of the reaction between HRP and hydrogen peroxide (H2O2). In the presence of H2O2, HRP catalyzes the oxidation of HQ quinone, wherein the current reduction associated with this process is monitored. (AU)