Capture of Single Silver Nanoparticles in Nanopore Arrays Detected by Simultaneous Amperometry and Surface-Enhanced Raman Scattering

Journal Article · Tue Mar 12 00:00:00 EDT 2019 · Analytical Chemistry

DOI:https://doi.org/10.1021/acs.analchem.8b05748· OSTI ID:1770939

Kim, Ju-Young  ^[1]; Han, Donghoon  ^[2]; Crouch, Garrison M.  ^[1]; Kwon, Seung-Ryong  ^[1]; Bohn, Paul W.  ^[1]

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1. Univ. of Notre Dame, IN (United States)
2. The Catholic Univ. of Korea, Gyeonggi-do (Korea)

The attoliter volumes and confinement abilities of zero-dimensional nanopore-electrode arrays (NEAs) hold considerable promise for examining the behavior of single nanoparticles. In this work, we use surface-enhanced Raman scattering (SERS) in tandem with amperometry in order to monitor single Ag Raman-sentinel nanoparticles transported to and captured in single nanopores. To that end, highly ordered solid-state NEAs were fabricated to contain periodic arrays of nanopores, each housing a single recessed Au-ring electrode. These were used to electrostatically capture and trap single silver nanoparticles (AgNPs) functionalized with the electrochemically stable Raman reporter, 1,4-bis(2-methylstyryl)benzene (bis-MSB). Transport and capture of the bis-MSB-tagged AgNPs in the nanopores was followed by simultaneous amperometry and SERS signals characteristic of AgNP oxidation and enhanced Raman scattering by bis-MSB at silver–gold hot spots, respectively. The frequency and magnitude of oxidation-current spikes increased with stepwise increases in DC voltage, and characteristic bis-MSB SERS spectra were observed. Under AC excitation, on the other hand, two distinctly different types of SERS signals were observed, independent of frequency and amplitude: (1) strong, transient (<10 s) spectra and (2) slow (>100 s) monotonically diminishing spectra. We hypothesize that the former behavior results from AgNP aggregates, whereas the latter occurs as a result of multiple incomplete AgNP-oxidation events in succession. Here, these results show that attoliter-volume NEAs are competent for acquiring concurrent SERS spectra and for amperometry of single nanoparticles and that together these measurements can illuminate the collision dynamics of nanoparticles in confined environments.

• Research Organization: Univ. of Notre Dame, IN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: FG02-07ER15851
• OSTI ID: 1770939
• Journal Information: Analytical Chemistry, Vol. 91, Issue 7; ISSN 0003-2700
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
77 NANOSCIENCE AND NANOTECHNOLOGY
Metal nanoparticles
Nanoparticles
Electrodes
Raman spectroscopy
Nanopores