Nanofluidic flow assisted assembly of dispersed plasmonic nanostructures into shallow nanochannel sensors
The authors present a method for assembling plasmonic nanostructures into already-sealed shallow nanochannel-based nanofluidic sensor structures. This method is termed as nanofluidic-flow-assisted-assembly (NFAA). NFAA utilizes nanofluidic flows with large shear rate and stress to deposit high-areal...
Gespeichert in:
Veröffentlicht in: | Journal of vacuum science and technology. B, Nanotechnology & microelectronics Nanotechnology & microelectronics, 2016-11, Vol.34 (6) |
---|---|
Hauptverfasser: | , , , , , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | The authors present a method for assembling plasmonic nanostructures into already-sealed shallow nanochannel-based nanofluidic sensor structures. This method is termed as nanofluidic-flow-assisted-assembly (NFAA). NFAA utilizes nanofluidic flows with large shear rate and stress to deposit high-areal-density, well-dispersed plasmonic nanoparticles (NPs) into shallow nanochannel sensing areas. In particular, in a NFAA process, the nano/microfluidic structures are first patterned into a Si or SiO2 substrate and permanently sealed with fused quartz coverslips using plasma sealing. Afterward, a colloidal solution of plasmonic NPs is driven into the shallow nanochannel structures. In the shallow nanochannel areas, the large shear rate and stress of the nanofluidic colloidal solution flow results in the deposition of well-dispersed NPs and effectively prevents undesirable aggregation of NPs. Using NFAA, the authors have demonstrated the deposition of well-dispersed Au NPs with various areal densities (102–104
μm−2) into shallow nanochannels. The light absorbance peak of NFAA-coated Au NPs exhibits the narrower full-width-at-half-maximum than that of the Au NPs directly deposited from a colloidal solution, further indicating that NFAA can result in the higher degree of dispersion of high-density NPs. The authors also demonstrated that the additional nanoscale anchoring structures prepatterned in a shallow nanochannel, in combination with NFAA processes, can enable selective deposition of functional nanoparticles around designated locations. This work provides a nanofabrication scheme for introducing functional nanostructures into already-sealed nanofluidic structures. This method could be further generalized to enable integration of various electrically/optically active nanoscale components into permanently sealed nano/microfluidic structures and therefore address the incompatibility among the fabrication routes of these device structures. |
---|---|
ISSN: | 2166-2746 2166-2754 |
DOI: | 10.1116/1.4967748 |