Design of single nanoparticle optical sensors for imaging single receptor molecules on single living cells

ANYL 382

X. Nancy Xu, xhxu@odu.edu, Tao Huang, and Parkash D. Nallathamby. Department of Chemistry and Biochemistry, Old Dominion University, 4541 Hampton Blvd., Norfolk, VA 23529
At the cellular level, a very few of protein molecules can induce a significant cellular response. At such low concentration (far below the disassociation constant), conventional tools are unable to effectively detect these crucial molecules, hindering the better understanding of vital roles of trace amount of protein molecules on single living cells and their related biochemical pathways. We have developed and characterized single nanoparticle sensors, and used single nanoparticle sensors to image and detect individual protein molecules on single living cells, to map its distribution density and coverage on single living cells, and to monitor its binding reaction in real time. Characterization of binding affinity of single nanoparticle sensor shows that antibody conjugated nanoparticles preserve the primary biological activity of antibody. The dynamic range of single nanoparticle sensors is 0-30 molecules per living cell. The detailed experimental design and prospective applications will also be discussed in this presentation.