Electrochemical immunosensor for dengue virus serotypes based on 4-mercaptobenzoic acid modified gold nanoparticles on self-assembled cysteine monolayers

Currently, Dengue is a worldwide health problem and no effective vaccine or specific medication. Thus, the development of new diagnostic methods has been the focus of efforts to combat the disease. Immunosensor based on gold nanoparticles (AuNPs) and self-assembled monolayers of cysteine was developed for dengue virus (DENV-1, DENV-2, DENV-3 and DENV-4) detection. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to monitor the signal response of the each dengue serotype in different dilutions. Scanning electron microscopy was used to characterize the surface of the immunosensor before and after exposure to DENV. In this work, four different immunosensors with specificity for DENV1-4 were obtained. EIS and CV measurements demonstrate the ability of the immunosensor to recognize all four studied DENV serotypes showing sensitivity and selectivity. The real part of the impedance was higher for Cys-MBA-AuNPs-anti-DENV antibody sensor system after interaction to different concentrations of DENV (1-4) compared to the sensor system without immunoreaction on their surface, revealing an increased blockage of the electron transfer. In addition, the surface coverage values indicate a good recognition of DENV by anti-DENV antibody. The new sensor platform consists of a single method, more affordable than conventional immunoassays and creates expectation on future production of new real-time devices for diagnosis of pathologies caused by virus. (C) 2015 Elsevier B.V. All rights reserved.