Plasmonic Silver Nanowire Structures for Two-Dimensional Multiple-Digit Molecular Data Storage Application

The surface-enhanced Raman scattering (SERS) spectrum exhibits huge potential as an alternative data storage element. Using plasmonic nanostructures as the physical building blocks,where probe molecules are adsorbed, their corresponding structural and SERS information are stored within a finite volume of plasmonic nanostructures. However, the current SERS developments hampered by the diffiiculty in fabricating g quantitative and homogeneous SERS we introduce the concept of "plasmonic molecular data storage" using SERS intensity as the basic data storage element the digit). SERS signal is quantitatively tunable by manipulating the orientation (hence h e localized surface plasmon mode) of e respective nanowire nanostructures, to achieve multiple-digit SERS intensity data storage. We address the, reproducibility problem by fabricating homogeneous plasmonic nanowire structures using two-photon lithography and thermal evaporation. Silver (Ag) nanowires of different orientations carrying different digits of molecular information Can be combined to form sophisticated 2D geometrical structures such as geometrical patterns, letters in the alphabet, and complex tessellated reptiles to impart multiple-digit-per-microstructure data storage. In particular, a 7-digit,SERS information storage system has been achieved by tuning the Ag nanowires' orientation from 00 to 90 at Is intervals. Spatial data, especially the coordinates and topology, brought about by the predefined Ag nanowire structures create an additional level of information to the plasmonic data storage system. Using 1 byte (8 binary digits) as the basis of comparison, our 7-digit platform is able to store 22 500-fold denser information than the binary system. In addition, our plasmonic nanowire data storage system also provides unique physical morphology and chemical Raman information. It is analogous to optical data storage, but it acquires richer multidimensional information and exhibits higher spectral resolution than the broader-band response of conventional optical spectroscopic techniques.