Investigation of labeling FRET pairs to biomolecules for the development of dual-receptor biosensors

Abstract

We report herein on the development of a dual receptor detection method for enhanced biosensor monitoring. The proposed scheme requires the integration of a chemical transducer system with two unique protein receptors that bind to a single biological agent. Optical transduction occurs because the two protein receptors are tagged with special molecular groups. When bound to a single biological agent, these fluorescently labeled proteins undergo a change in fluorescence. This `fluorescent switching' relies on the well-known mechanisms of fluorescent resonance energy transfer (FRET). The paper focuses on the investigation and optimization of the chemical transduction system (FRET). A number of FRET dye pairs were tested in a spectrofluorimeter, and promising FRET pairs (FITC/TRITC and DMACA/FITC) were further tagged to the protein, avidin and its ligand, biotin. Due to their affinities, the FRET-tagged biomolecules combine in solution, resulting in a stable, fluorescent signal from the acceptor FRET dye with a simultaneous decrease in fluorescent signal from the donor FRET dye. The results indicate that the determined FRET pairs can be utilized in the development of dual receptor sensors.