NANO-SCALE FLUORO-BIOSENSORS EXHIBITING A LOW FALSE ALARM RATE FOR RAPID DETECTION OF BIOLOGICAL CONTAMINANTS

摘要

A sensing system incorporating a nano-scale fluoro-biosensor for detection of specifically targeted bio-contaminants (targets). Select embodiments use fluorescent nanoparticles such as quantum dots (QD) conjugated to antibody fragments to form a sensor for a specific bio-contaminant based on fluorescent resonance energy transfer (FRET). A quenching dye may be used to label an analog, while a specific antibody is covalently bonded to a hydrophilic QD. Coupling of QD labeled antibodies and quencher labeled analogs provides enough proximity to produce appreciable FRET-based quenching. Any addition of the target displaces the dye-labeled bacteria, eliminating FRET-based quenching and results in a concentration-dependent increase in QD photoluminescence. Applications include rapid detection and identification, with a high degree of specificity and sensitivity, of a broad range of targets, including viral contaminants, e.g., in less than about three minutes. By using QDs of varying wavelengths the system may be adapted into a multiplexing immuno-assay.