Noble-metal nanocages comprise a novel class of nanostructures possessing hollow interiors and porous walls. They are prepared using remarkably simple galvanic replacement reaction between solutions containing metal precursor salts Ag through polyol reduction. The electrochemical potential difference the two species drives reaction, with reduced depositing on surface nanostructure. In our most studied example, involving HAuCl(4) as precursor, resultant Au is deposited epitaxially nanocubes,...

Gold nanocages with a relatively small size (e.g., ∼45 nm in edge length) have been developed, and the structure of these was tailored to achieve strong absorption near-infrared (NIR) region for photothermal cancer treatment. Numerical calculations show that nanocage has large cross section 3.48 × 10-14 m2, facilitating conversion NIR irradiation into heat. The gold were conjugated monoclonal antibodies (anti-HER2) target epidermal growth factor receptors (EGFR) are overexpressed on surface...

Gold nanocages of <40 nm in dimension have been synthesized using the galvanic replacement reaction between Ag nanocubes and HAuCl4 an aqueous solution. By controlling molar ratio HAuCl4, gold could be tuned to display surface plasmon resonance peaks around 800 nm, a wavelength commonly used optical coherence tomography (OCT) imaging. OCT measurements on phantom samples indicate that these moderate scattering cross-section ∼8.10 × 10-16 m2 but very large absorption ∼7.26 10-15 m2, suggesting...

We have evaluated the catalytic properties of Au-based nanostructures (including nanocages, nanoboxes, and solid nanoparticles) using a model reaction based on reduction p-nitrophenol by NaBH(4). From average rate constants at three different temperatures, we determined activation energy, entropy activation, pre-exponential factor for each type Au nanostructure. The kinetic data indicate that nanocages are catalytically more active than both nanoboxes nanoparticles probably due to their...

Gold nanocages represent a new class of nanomaterials with compact size and tunable optical properties in the near-infrared region. They passively accumulate tumor after intravenous injection. By exposing tumors to diode laser, photothermal effect Au selectively destroys tissue minimum damage surrounding healthy tissue.

The rapid reduction of Na2PdCl4 by ethylene glycol in the presence poly(vinyl pyrrolidone) (PVP) has recently been demonstrated as a convenient method generating Pd cubooctahedra and twinned nanoparticles. Here we describe new procedure where triangular or hexagonal nanoplates could be selectively synthesized manipulating kinetics polyol process. More specifically, rate was substantially reduced through introduction Fe(III) species O2/Cl- pair, two wet etchants for Pd(0). etching power pair...

Poly(vinyl pyrrolidone) (PVP) has been extensively used in the solution-phase synthesis of many types colloidal particles, where it is mainly considered as a steric stabilizer or capping agent with major role to protect product from agglomeration. In recent study, we discovered that hydroxyl end groups PVP could also serve very mild reductant for kinetically controlled Ag nanoplates yields high 75%. Here further demonstrate hydroxyl-terminated well-suited aqueous circular, triangular, and...

Abstract The galvanic replacement reaction between a Ag template and HAuCl 4 in an aqueous solution transforms 30–200 nm nanocubes into Au nanoboxes nanocages (nanoboxes with porous walls). By controlling the molar ratio of to , extinction peak resultant structures can be continuously tuned from blue (400 nm) near‐infrared (1200 region electromagnetic spectrum. These hollow nanostructures are characterized by extraordinarily large cross‐sections for both absorption scattering. Optical...

Silver nanocubes dispersed in water were transformed into Pd−Ag or Pt−Ag nanoboxes by adding either Na2PdCl4 Na2PtCl4. By controlling the amount of noble metal salt added, and therefore molar ratio Na2PtCl4 to Ag, we could tune surface plasmon resonance peak nanostructures across entire visible spectrum, from 440 730 nm. Replacement Ag with Pd resulted formation a nanobox composed alloy single crystal, but formed after replacement Pt was instead distinct nanoparticles. DDA calculations...

Nanostructured materials provide a promising platform for early cancer detection and treatment. Here we highlight recent advances in the synthesis use of Au nanocages such biomedical applications. Gold represent novel class nanostructures, which can be prepared via remarkably simple route based on galvanic replacement reaction between Ag nanocubes HAuCl(4). The have tunable surface plasmon resonance peak that extends into near-infrared, where optical attenuation caused by blood soft tissue...

A novel single-walled carbon nanotube (SWNT)-based tumor-targeted drug delivery system (DDS) has been developed, which consists of a functionalized SWNT linked to tumor-targeting modules as well prodrug modules. There are three key features this nanoscale DDS: (a) use SWNTs biocompatible platform for the therapeutic drugs or diagnostics, (b) conjugation an anticancer agent (taxoid with cleavable linker) that is activated its cytotoxic form inside tumor cells upon internalization and in situ...

Platinum nanowires of approximately 100 nm in length and 5 diameter have been synthesized by reducing H(2)PtCl(6) with ethylene glycol the presence poly(vinyl pyrrolidone) (PVP) a trace amount Fe(3+) or Fe(2+). The wires were generated at final stage synthesis, which involved formation several intermediate species. Fe(2+) ions had dual functions synthesis: they induced aggregation Pt nanoparticles into larger structures that served as nucleation sites, greatly reduced reaction rate...

Consumption of whole grains has been associated with reduced risk developing major chronic diseases. These health benefits have attributed in part to their unique phytochemicals. Little is known about the complete profiles phytochemicals and antioxidant activities different adlay varieties. The objectives this study were determine three varieties, including both free bound total phenolics flavonoids, activity adlay. free, bound, phenolic contents samples ranged from 31.23 45.19 mg gallic...

Early diagnosis, accurate staging, and image-guided resection of melanomas remain crucial clinical objectives for improving patient survival treatment outcomes. Conventional techniques cannot meet this demand because the low sensitivity, specificity, poor spatial resolution, shallow penetration, and/or ionizing radiation. Here we overcome such limitations by combining high-resolution photoacoustic tomography (PAT) with extraordinarily optical absorbing gold nanocages (AuNCs). When...

Uniform cubooctahedral nanoparticles of Pd were synthesized using a modified polyol process. Like the silver system, underwent dissolution due to oxidative etching by Cl-/O2. In early stage etching, twinned particles in sample selectively removed leave behind uniform, single-crystal cubooctahedra. If was allowed continue, cubooctahedra also attacked and partially dissolved. Understanding role is critical achievement both uniform shape size.

Abstract Background The tuberous root of sweetpotato is an important agricultural and biological organ. There are not sufficient transcriptomic genomic data in public databases for understanding the molecular mechanism underlying formation development. Thus, high throughput transcriptome sequencing needed to generate enormous transcript sequences from gene discovery marker Results In this study, more than 59 million reads were generated using Illumina paired-end technology. De novo assembly...

Gold−silver alloy nanocages with controllable pores on the surface have been synthesized via galvanic replacement reaction between truncated Ag nanocubes and aqueous HAuCl4. Unlike in previous studies, initiation of started a way, simultaneously from eight corners where {111} facets were exposed. The formation cubic at all was determined by capping agent, poly(vinyl pyrrolidone) (PVP), which preferentially covered {100} nanocube.

Morphological control over platinum nanoparticles was realized by varying the amount of NaNO3 added to a polyol process, where H2PtCl6 reduced ethylene glycol form PtCl42- and Pt0 at 160 °C. As molar ratio between increased from 0 11, morphology Pt evolved irregular spheroids with rounded profiles tetrahedra octahedra well-defined facets. Absorption spectroscopy studies suggest that nitrate nitrite in early stage synthesis, could then stable complexes both Pt(II) Pt(IV) species. result,...

Silver nanocubes with edge lengths controllable in the range of 30−200 nm were synthesized using an approach based on seeded growth. The keys to success this synthesis are use single-crystal Ag seeds direct growth and AgNO3 as a precursor elemental Ag, where byproduct HNO3 can block both homogeneous nucleation evolution into twinned nanoparticles. Either spherical (in shape cuboctahedron) or cubic could be employed for process. length resultant readily controlled by varying amount used,...

Pd nanocubes between 8 and 50 nm in size were synthesized at the same concentration of Na2PdCl4 precursor by controlling number seeds formed nucleation stage. Increasing FeCl3, an oxidative etchant for Pd, reduced led to formation larger nanocubes. The exhibited surface plasmon resonance peaks visible region, locations which matched with results discrete dipole approximation calculation. While 25 oxidized air form Pd@PdO core−shell structures, 8-nm stable over 90 days.