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Biomolecular detection using Localized Surface Plasmon Resonances (LSPR) has been extensively investigated
because these techniques enable label-free detection. The high-density metal nanopatterns with tunable LSPR
characteristics have been used as refractive index sensing because LSPR property is highly sensitive to refractive index
change of surroundings. Meanwhile, Colloidal lithography is a robust method for fabricating regularly ordered
nanostructures in a controlled and reproducible way using spontaneous assembly of colloidal particles. In this study,
nanopatterns on UV-curable polymer were prepared via colloidal lithography. Then, metallic nanograil arrays with high
density were fabricated by sputtering noble metals such as gold and subsequent removal of residual polymers and
colloidal particles. From Finite-Difference Time-Domain Method (FDTD) simulations and reflectance spectra, we found
that multiple dipolar plasmon modes were induced by gold nanograil arrays and each mode was closely related with
structural parameters. LSPR characteristics of gold nanograil arrays could be tuned by varying the fabrication conditions
to obtain optimal structures for LSPR sensing. Sensing behavior of gold nanograil arrays was tested by applying various
solvents with different refractive indices and measuring the variations of LSPR dips. Finally, gold nanograil arrays as
LSPR sensors were integrated in optofluidic devices and used to achieve real-time label-free monitoring of biomolecules.
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