Real-Time SERS-Tracking of Adenine-Gold Charge Transfer Complex Formation on Nano-Cavities Shaped Plasmonic Crystals

Understanding binding of DNA bases with gold
surfaces is crucial for designing reliable tools in biosensing technology
and organic-based electronics. Herein, we discuss an application of
quasi periodic plasmonic nanocavities fabricated by a top-down
method to study adenine interactions with gold surfaces. We report
plasmon-mediated homogenous catalysis of adenine-gold complex
formation, when adenine is deposited onto surfaces in different ways.
In particular, we elucidate how additional information can be obtained
by adsorbate irradiation with laser far from resonant conditions with a
low-localized, high-integral field substrate. A comparative study
between mono- and multilayers on gold is proposed, offering a
solution to the controversial question of adenine orientation on gold
surfaces by revealing charge transfer complex formation during realtime
surface enhanced Raman scattering tracking. Additionally, the
designed nanocavity-based plasmonic substrates exhibit a high sensitivity with a limit of detection ? 25 nM.