Porous Au-Seeded Ag Nanorod Networks Conjugated With Dna Aptamers For Impedimetric Sensing Of Denv-2

An efficient nanobioconjugate has been developed as electrode coating material by self-assembling our newly reported porous Au-seeded Ag nanorod networks (Hy-Au@AgNR840-Ass) with a thiol modified DNA aptamer (HS-Apt) for the early-stage specific detection and quantification of Dengue virus (serotype 2). Characterization of the precursors (Hy-Au@AgNR840 and Hy-Au@AgNR840-Ass) for effective fabrication of the bioconjugate (HyAu@AgNR840-Ass-S-Apt) was performed by using microscopic (TEM and AFM), spectroscopic (Absorbance, XPS, and SERS), scattering (DLS) and diffractometric (XRD) techniques and has been detailed in our previous publication whereas the binding affinity between the bioconjugate and different serotypes of dengue is studied here using low cost electrochemical impedimetric spectroscopy (EIS). Despite the structural similarity between virion particles of different dengue serotypes, we can detect the most prevalent DENV-2 specifically by using our nonenzymatic nanobioconjugate assay for the first time through the impedimetric technique. The cross-reactivity is checked in presence of closely related serotypes like DENV-1 & DENV-3. The key achievement of this study lies in its ability in the direct detection of DENV-2 serotype without the aid of an enzyme or antibody in dengue infected blood up to similar to 100 infectious units per mL.