Investigation of an optical dual receptor method to detect HIV

A novel sensing method for detecting the human immunodeficiency virus (HIV) is reported. The method utilized a two receptor-binding event and required the integration of a chemical transducer system with two unique protein receptors, CD4 and Mab, a monoclonal antibody, which bind to gp120, a single-surface protein receptor on HIV. The chemical transduction system was based on the distance-dependent principle of fluorescence resonance energy transfer (FRET). During the binding event, the two fluorophore-labeled receptors docked at the surface of the gp120. The resulting close proximity of the two fluorophores upon binding initiated an energy transfer resulting in a detectable change of fluorescence. Donor fluorophore to acceptor fluorophore ratios were examined to ascertain any effects on energy transfer. The experiments demonstrated that higher ratios of acceptor fluorophores to donor fluorophores resulted in enhanced energy transfer. In-solution testing proved the feasibility of the dual receptor technique in detecting the presence of gp120 with a limit of detection of 5 ng/ml.