This project involves the development of antibody-based surface-enhanced Raman scattering (SERS) nanosensors for the intracellular monitoring of specific antigens (e.g., proteins, etc.).  These immuno-nanosensors are fabricated on silica nanospheres that can be positioned to specific locations inside individual cells via optical tweezers.  By employing sensors for various biochemical species these nanosensors can be used for pre-symptomatic detection of exposure to toxins or biological agents  as well as for provide a greater understanding of fundamental cellular responses to a wide array of stimuli.