posted on 2017-01-15, 00:00authored byYixian Wang, Xiaonan Shan, Hui Wang, Shaopeng Wang, Nongjian Tao
Nanomaterials have
been widely used in energy and sensing applications
because of their unique chemical and physical properties, especially
their surface reactions. Measuring the local reactions of individual
nanomaterials, however, has been an experimental challenge. Here we
report on plasmonic imaging of surface electrochemical reactions of
individual gold nanowires (AuNWs). We coated a gold thin film (plasmonic
sensing layer) with a dielectric layer (Cytop) with refractive index
close to that of water, and then a graphene layer for electrical contact.
This design removed the interference from the sensing layer while
preserving sharp surface plasmon resonance, which allowed us to obtain
cyclic voltammograms of surface electrochemistry of individual AuNWs
for the first time. We also investigated the difference in the electrochemical
reactions of AuNWs and Au surfaces, and local distribution of electrochemical
activities within a single AuNW.