A new type of lipid-based ultrasensitive optical biosensor is proposed to be investigated, developed, fabricated and engineered for mass production. A specially designed fixed wavelength polarization fluorimeter enables the measurement of the difference in anisotropy of fluorescent light emitted from lipid-based probes. This difference reflects the fluidity and packing changes in a liquid-crystalline lipid matrix that occur because of the conformational changes that follow the receptor-ligand binding. For this, the receptor has to be incorporated into the lipid matrix, as naturally takes place in a cell membrane. The proposed biosensor has at least two orders of magnitude higher sensitivity than the widely used radio labeling method. In addition, a preliminary study suggests that the proposed sensor will have a linear quantitative response up to saturation level. Based on POC's capabilities in the advanced technology of holographic gratings, filters, and optical measurements, an automatic, compact and self-contained device will be built, and capable of detecting minute amounts of organic agents, such as drugs and toxins, and with an important application to the detection of the human immunodeficiency virus (HIV). The possibility of early detection of the virus itself (not of the subsequent antibody) makes the proposed approach especially attractive.
