Iron-Assisted Synthesis of Highly Monodispersed and Magnetic Citrate-Stabilized Small Silver Nanoparticles

Abstract

Herein, we present an optimized bottom-up approach for the fabrication of homogeneous small spherical silver nanoparticles, with average diameter sizes ranging from 10 to 30 nm and the associated plasmon resonances located between 390 and 410 nm. The presented method relies on the use of tiny amounts of Fe­(III) as the silver dopant during the growth process, which enables the production of very homogeneous nanoparticles (standard deviations <6%). The characterization of the obtained materials with surface-enhanced Raman scattering spectroscopy shows optical enhancing properties similar to, or even better than, those observed with standard silver nanoparticles. Moreover, these noble nanomaterials are also endorsed with an intrinsic magnetic functionality.

Widefield SERS for High‐Throughput Nanoparticle Screening

“…Briefly, 15 nm diameter silver NPs (i.e., satellites, Figure 1b) were produced following a previously reported protocol. [16] Silver NPs with 90 nm diameter were prepared via kinetically controlled growth [17] (i.e., cores, Figure 1b) using citrate and ascorbate as both surfactants and reducing agent. Both NPs were then encoded with the SERS reporters by first coating them with mercaptoundecanoic acid (MUA) followed by addition of the molecular labels, or SERS codes.…”

Widefield SERS for High‐Throughput Nanoparticle Screening

“…Figure 1 explains our SERS‐particle synthesis strategy and shows TEM images of the SERS encoded NP‐aggregates [15] which we will refer to as core@satellite structures throughout the manuscript. Briefly, 15 nm diameter silver NPs (i.e., satellites, Figure 1b) were produced following a previously reported protocol [16] . Silver NPs with 90 nm diameter were prepared via kinetically controlled growth [17] (i.e., cores, Figure 1b) using citrate and ascorbate as both surfactants and reducing agent.…”

Design and fabrication of bimetallic plasmonic colloids through cold nanowelding

“…1 minute later, a solution previously incubated for 5 min containing AgNO 3 (198 μL, 0.1 M) and FeN 3 O 9 ·9H 2 O (22 μL, 0.001 M) was also added. 33 Boiling and stirring were continued for 1 h. The samples were concentrated by solvent evaporation until a final Ag 0 concentration of 10 −3 M was reached. The obtained NP diameter was 33 ± 3 nm.…”

“…The colour turned from transparent to dark red and finally to bright yellow. 33 After 1 h, the samples were concentrated by solvent evaporation until a final Ag 0 concentration of 10 −3 M was reached. The NP size was 15 ± 2 nm.…”

“…The obtained positively charged bundles were redispersed in 500 μL of water. 33 Boiling and stirring were continued for 1 h. The samples were concentrated by solvent evaporation until a final Ag 0 concentration of 10 −3 M was reached. The obtained NP diameter was 33 ± 3 nm.…”