| AVS 56th International Symposium & Exhibition | |
| Advanced Surface Engineering | Tuesday Sessions |
| Session SE+TF-TuA |
| Session: | Glancing Angle Deposition II |
| Presenter: | W. Zhang, University of Illinois at Urbana-Champaign |
| Authors: | W. Zhang, University of Illinois at Urbana-Champaign S.M. Kim, Chung-Ang University, Korea N. Ganesh, Intel I. Block, University of Illinois at Urbana-Champaign P. Mathias, University of Illinois at Urbana-Champaign B.T. Cunningham, University of Illinois at Urbana-Champaign |
| Correspondent: | Click to Email |
Planar photonic crystals have been used as the basis of many biological sensing devices. Here, we successfully demonstrated that the combination of the photonic crystal structures and a dielectric nanorod coating prepared by the glancing angle deposition technique can lead to significant increases in the device sensitivity.
By incorporating a TiO2 nanorod coating onto the label-free biosensor structure, the surface area of the device is increased. The sensitivity of high surface area sensors is compared with sensors without the high surface area coating. Results for detection of polymer films, proteins, and small molecules indicate up to a seven-fold enhancement of detected adsorbed mass density.
When a TiO2 nanorod coating is applied on top of the high index layer of an enhanced fluorescence biosensor, the emission intensity of a fluorescent dye on the device is increased by over one hundred times compared to a reference glass slide. The increased sensitivity is due to the combined effects of enhanced near-fields and enhanced surface area. The sensitivity is further increased by close to two hundred times when a TiO2 nanorod film is used as the high index layer of the photonic crystal structure.
The planar photonic crystal is also combined with a SiO2–Ag “post-cap” nanostructure for applications in surface-enhanced Raman spectroscopy (SERS). It is demonstrated that the resonant near fields of the photonic crystal could be used to efficiently couple light from a laser to the Ag nanoparticles to achieve a high SERS enhancement factor.