A rapid, label-free, and broadly applicable chemical analysis platform for nanovesicles and subcellular components is highly desirable for diagnostic assays. We demonstrate an integrated nanogap plasmonic sensing platform that combines subvolt dielectrophoresis (DEP) trapping, gold nanoparticles (AuNPs), and a lineated illumination scheme for real-time, surface-enhanced Raman spectroscopy (SERS) imaging of biological nanoparticles. Our system is capable of isolating suspended sub-100 nm vesicles and imaging the Raman spectra of their cargo within seconds, 100 times faster than conventional point-scan Raman systems. Bare AuNPs are spiked into solution and simultaneously trapped with the nanovesicles along the gap to boost local optical fields. In addition, our platform offers simultaneous and delay-free spatial and temporal multiplexing functionality. These nanogap devices can be mass-produced via atomic layer lithography and provide a practical platform for high-speed SERS analysis of biological nanoparticles.
Bibliographical noteFunding Information:
This work was supported by grants from the National Science Foundation (NSF ECCS Grant No. 1610333 to C.T.E. and S.-H.O.; NSF CBET Grant No. 1605683 to W.-C.S.) and the Minnesota Partnership for Biotechnology and Medical Genomics (A.B., N.J.W., and S.-H.O.). C.T.E. and D.J.K. acknowledge support from the NSF Graduate Research Fellowship Program (GRFP) and A.B. acknowledges support from the University of Minnesota Doctoral Dissertation Fellowship. N.J.W. acknowledges support from Lehigh University. Device fabrication was performed at the University of Minnesota Nanofabrication Center, which receives support from the NSF through the National Nanotechnology Coordinated Infrastructure (NNCI) program.
© 2018 American Chemical Society.
- gold nanoparticle
- surface-enhanced Raman scattering (SERS)