Plasmonic nanostructures made from noble metals have broad application in chemical and biological sensors, food safety, environmental monitoring, and biomedical devices. Scalable techniques to fabricate these structures with dimensions smaller than the wavelengths of visible light are critical to enable their widespread use. In this work, we demonstrate a large-area, high-throughput process to fabricate one-dimensional nanolines and two-dimensional square nanodisks with sub-micron dimensions for use as plasmonic biosensors. Commercially available HD-DVDs were employed as low-cost, large-area “masters” to prepare polymeric stamps with linear features 200 nm wide at a pitch of 400 nm. This pattern was transferred onto gold films via chemical lift-off lithography and selective wet etching, thereby producing large-area arrays of plasmonic Au nanolines. Repeating the patterning process with stamps rotated 90° from the initial patterning orientation enabled the conversion of 1D nanolines to 2D arrays of nanodisks. By tracking peak shifts in the extinction spectra of these plasmonic nanostructures, it was possible to conduct transmission-mode refractometric sensing experiments in aqueous environments, and the corresponding bulk refractive index sensitivities were determined to be in the range of 200–500 nm/refractive index units. These sensing capabilities were translated into high-sensitivity detection of the interactions between these plasmonic nanostructures and different classes of biomacromolecules, namely zwitterionic lipid vesicles and bovine serum albumin protein. Taken together, the results demonstrate how this scalable patterning technique provides a simple and economical means to produce large-area plasmonic nanostructures for a variety of applications in optoelectronics and biosensing.

Scalable fabrication of one- and two-dimensional gold nanostructures for plasmonic biosensing applications

256th National Meeting (2018)

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