Receptor-conjugated Nanoparticles to Detect Biological Warfare Agents

Recent research has examined the feasibility of detecting biological warfare agents by conjugating their antibodies (receptors) with taggant nanoparticles (also known as “quantum dots”), which subsequently fluoresce upon excitation, when they are bound to a specific biowarfare agent, or its simulant. Furthermore, when they react with their target bacteria, optically excited nanoparticle-receptor conjugates generate spectra in which the intensities of primary emission peaks are diminished, while the secondary emission peaks increase in intensities, i.e., energy is transferred from major peaks to minor peaks. These optical emission spectral signatures, with emission wavelength shifts of 140 nm in some cases, strongly suggest the possibility of homogeneous (one step) assays, leading to positive detection of bacterial agents, without wash steps using nanoparticle-receptor conjugates.