DNA-Modified Core−Shell Ag/Au Nanoparticles

Aqueous synthesis and characterization of Ag and Ag–Au nanoparticles: addressing challenges in size, monodispersity and structure

“…Silver metal has many desirable chemical and physical traits, such as conductivity, catalytic activity and abundance, but it is the optical properties of silver NPs that make it an exceptional candidate for use in bio-diagnostics and sensing, which has been illustrated by such researchers as Cao et al (2001), Cui et al (2006) and Lu et al (2006). The exceptionally high extinction coefficient of Ag NPs associated with the very high enhancement ability in Raman spectroscopy has led to their use as sensing agents in several biological applications, such as the detection of proteins, amino acids, or DNA, by several researchers, including Cao et al (2001) and Cui et al (2006).…”

“…Silver metal has many desirable chemical and physical traits, such as conductivity, catalytic activity and abundance, but it is the optical properties of silver NPs that make it an exceptional candidate for use in bio-diagnostics and sensing, which has been illustrated by such researchers as Cao et al (2001), Cui et al (2006) and Lu et al (2006). The exceptionally high extinction coefficient of Ag NPs associated with the very high enhancement ability in Raman spectroscopy has led to their use as sensing agents in several biological applications, such as the detection of proteins, amino acids, or DNA, by several researchers, including Cao et al (2001) and Cui et al (2006). Despite the promising properties displayed by Ag NPs though, there have been several difficult challenges to address, namely the ability to synthesize Ag NPs in aqueous phase with a desired size, shape or monodispersity (Sharma et al 2009), and the ability to associate the resulting Ag particles with the desired biomolecules so that detection can be performed (Cao et al 2001).…”

“…The exceptionally high extinction coefficient of Ag NPs associated with the very high enhancement ability in Raman spectroscopy has led to their use as sensing agents in several biological applications, such as the detection of proteins, amino acids, or DNA, by several researchers, including Cao et al (2001) and Cui et al (2006). Despite the promising properties displayed by Ag NPs though, there have been several difficult challenges to address, namely the ability to synthesize Ag NPs in aqueous phase with a desired size, shape or monodispersity (Sharma et al 2009), and the ability to associate the resulting Ag particles with the desired biomolecules so that detection can be performed (Cao et al 2001).…”

Advanced AuNMs as nanomedicine’s central goals capable of active targeting in both imaging and therapy in biomolecules

“…In general, the reported synthesis methods of spherical AuNMs can be categorized as followed: (1) citrate reduction; (2) Brust-Schiffrin phase transfer synthesis; (3) other sulfur-containing ligands method; (4) soft templates including micro emulsion, reversed Micelles, surfactants, membranes and polyelectrolytes; (5) seedmediated growth; and (6) physical methods [28]. In addition, nonspherical nanoparticles (NPs) such as Au nanorods (AuNRs) [29], Au nanocages [30], Au cubes [31], Au triangular prisms [32], as well as other unconventional structures like hollow tubes and even branched nanocrystals [33] have attracted significant research attention in the past two decades, since the properties of AuNMs are known to be strongly dependent on the size and shape of the particle [34]. Recently, a lot of excellent reviews have summarized how to achieve shape-and size-defined AuNMs with different techniques including solve thermal synthesis, seed-mediated growth, homogeneous nucleation and electrochemical method [35,36].…”

The impacts of nanotechnology on catalysis by precious metal nanoparticles

“…Such nanoparticles may be composed of a single, two or multiple metal elements. Core-shell nanoparticles with two or more metal components are typically made by sequential reduction of metal salt precursors in solution phase [56] . Hollow nanoparticles are often made by chemical etching methods; for example, using Ag nanoparticles as a sacrifi cial template in the etching reaction by Au(III) ions, a galvanic replacement reaction (or transmetalation reaction) occurs and gives rise to porous gold nanostructures [57] .…”