Innovative concept for detection and identification of biological toxins

The objective of the proposed Phase II project is to develop a hand-held, rapid plasmonic biosensor -- a detector based upon surfaceplasmon resonances (SPR) that incorporates a new class of supercharged proteins that functionalize a low-cost, disposable plasmonicchip. Each protein is designed to bind to a pre-determined toxin with high specificity. Upon successful binding, the protein superfoldsrelative to a typical immunoassay system, causing a correspondingly large change in the index of refraction immediately adjacent to thesurface of the plasmonic chip, that subsequently changes the transmission of light through the chip. In Phase I, we designed,synthesized, and characterized a supercharged protein that binds the model toxin heme. This protein demonstrated a large bindinginducedrefractive index change that is calculated to correspond to a 1001000 fold improvement in SPR signal relative to commerciallyavailable systems. In Phase II, these results will be extended to proteins that selectively bind to ricin, anthrax and sarin. Also in PhaseII, the hand-held optical module and plasmonic chip will be improved to increase performance and reduce cost. This project will beperformed by Phoebus Optoelectronics, in collaboration with the NSF IUCRC Center for Metamaterials at CUNY and Lockheed Martin.