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Abstract
Silver nanocubes were synthesized and their deposition and modification on silicon substrates was evaluated as a path to the controllable
assembly of larger nanostructures.
Synthesis of highly cubic, ~120 nm side-length silver nanocubes was accomplished through the development of a new variant of a
chloride-mediated polyol synthesis from literature, implementing control of headspace oxygen concentration in the range of 6.5 7.5 mol %. The
new variant method was found to greatly improve the reliability of the nanocube synthesis compared to the original method.
Drop-coating and electrophoretic deposition techniques were evaluated for producing even dispersions of nanocubes on silicon surfaces suitable
as a base for further modification and assembly. Electrophoretic immobilization at +50 V bias and 0.3 mm separation of electrodes and nanocube
solution was found to produce well dispersed layers of isolated cubes quickly.
Immobilized nanocubes were modified with single-stranded and double-stranded DNA sequences, and analyzed by Raman microscopy. Single
isolated nanocubes were found to produce weaker but detectable Raman signals compared to aggregated nanocubes on silicon. Single and
aggregated nanocubes with double stranded DNA modifications displayed a unique new peak at 1457 cm-1. This result is consistent with
literature, and demonstrates that single nanocubes can be isolated and probed for DNA modifications.