Fluorescent silver nanoparticle based highly sensitive immunoassay for early detection of HIV infection

Abstract

For the first time, we have engineered streptavidin labeled fluorescent silver nanoparticles for their application in immunosensing of biomolecules which will significantly increase sensitivity without compromising the specificity. A computational perspective for understanding the efficiency of the conjugation process is provided as a proof of concept. The fluorescence based sandwich immunoassay was demonstrated to detect HIV-1 p24 antigen in clinical specimens with improved sensitivity and specificity. The detection range of the fluorescent silver nanoparticle-based immunoassay (FSNIA) was found to be between 10 and 1000 pg mL⁻¹ in a linear dose dependent manner. False positives were not observed with plasma samples from healthy adults (HIV^−ve), hepatitis B (HBV^+ve) and hepatitis C (HCV^+ve). Plasma samples that were HIV^−ve showed no interference with detection of HIV-1 p24 antigen. This technology can be used in resource limited settings and easily adopted for the detection of other pathogen antigens.