Department of Electrical and Computer Engineering,
Department of Bioengineering
University of Illinois at Urbana-Champaign
Tuesday, Oct 16th, 11am, ESB 1001
Circulating exosomal miRNA represents a potentially useful class of bloodborne biomarkers for cancer. We present the initial proof-of-concept of an approach in which gold nanoparticle tags are prepared with thermodynamically optimized nucleic acid toehold probes that displace a oligonucleotide and reveal a capture sequence that is used to selectively pull down the target-probe-nanoparticle complex to a photonic crystal (PC) biosensor surface. By matching the surface plasmon resonant wavelength of the nanoparticle tag to the resonant wavelength of the PC nanostructure, the reflected light intensity from the PC is dramatically and locally quenched by the presence of each nanoparticle.
The talk described the optical operating principles of Photonic Resonator Absorption Microscopy (PRAM), the thermodynamic design of DNA toehold probes, and our first results demonstrating the detection limits, selectivity, and dynamic range of the assay.