Electroless Gold Plating of 316 L Stainless Steel Beads

Lam, Philippe; Kumar, K. S.; Wnek, Gary E.; Przybycien, Todd M.

doi:10.1149/1.1391964

Cited by 16 publications

(12 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We previously reported a weak reduction method for depositing gold onto aminosilane-coated magnetic particles. [21] Here we use a molecular coupling agent and a modified electroless gold plating method [22] to complete the gold shell. The sizes of the iron oxide and gold particles have a dramatic effect on the plasmonic and magnetic behavior of the core/shell nanoparticles.…”

mentioning

confidence: 99%

“…Overnight incubation of 0.5 mL of the 18 nm iron oxide particles in water with 6 mL of the gold seed nanoparticle suspension and 2 mL of ethanol led to the formation of iron oxide nanoparticles decorated with gold seed clusters, as shown in Figure 1b. Additional gold was reactively deposited [22] onto the Au seeds until they merged to form a shell around the iron oxide particles. 100 mL of the gold-seeded iron oxide nanoparticle suspension was mixed with 2 mL of freshly prepared gold plating solution consisting of 34 mM gold sodium thiosulfate and 57 mM ascorbic acid in deionized water.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Synthesis and Single‐Particle Optical Detection of Low‐Polydispersity Plasmonic‐Superparamagnetic Nanoparticles

et al. 2008

View full text Add to dashboard Cite

Both magnetic and plasmonic particles are of increasing interest for biomedical applications. Magnetic particles are currently used for magnetic separation, to collect tagged cells or DNA sequences, [1][2][3] and for magnetically guided drug delivery. [4][5][6] A key advantage of magnetism lies in the ability to control motion at a distance without perturbing the biological system, as would occur with a large electric field. Noble-metal nanostructures are beneficial not only because of their relative ease of biofunctionalization, but also for plasmonic biosensing. [7][8][9][10] Unlike quantum dots, [11] these particles do not show optical bistability or blinking making them competitive with fluorophores for quantifying the number of cell surface markers. [12,13] The main advantages of plasmonic particles are their extremely large molar extinction coefficients and resonant Rayleigh scattering efficiencies, [8] and the exceptional sensitivity of the surface plasmon resonance peak wavelength to changes in the local dielectric environment. Individual plasmonic nanoparticles and nanorods have been detected by using dark field optical microscopy. [13][14][15][16][17] In fact, by using nonmagnetically responsive gold-coated silica particles ($150 nm), Halas and co-workers have demonstrated the capability of gold-shell nanoparticles in detecting low concentrations of analytes in whole blood within minutes without any sample preparation.[18]Here we describe the preparation of iron oxide/gold core/ shell nanoparticles that can be moved magnetically and imaged optically. The synthesis of large-diameter ($150 nm) magnetic plasmonic three-layer composite particles has previously been reported, [19] but our focus here is on smaller particles. The small size of these nanoparticles approaches that of cellmembrane-bound antigens, and is in a range in which particles can be spontaneously internalized by endocytosis. We expect that the combination of magnetic responsiveness, facile bioconjugation, and a localized surface plasmon resonance in these smaller nanoparticles will open new possibilities for in vitro molecular and cell biological applications, including intracellular mechanical and chemical composition analyses, and magnetophoretic cell sorting according to the expression level of cell surface receptors. The magnetic forcẽ F m ¼ ðm pt Á rÞB * that can be applied to a particle depends on the particle magnetic moment m pt . Since m pt ¼ M s V pt , where M s is the saturation magnetization of the material and V pt is the particle volume, a larger size is generally preferable for a strong magnetic response. Thus there is a compromise between large magnetic moments and the desirability of small sizes for new applications.Gold, silver, and SiO 2 core/Au shell particles have been used for plasmonic sensing, where the surface plasmon peak wavelength shifts in response to small changes in the dielectric environment near the particle surface. A core/shell structure with the noble metal in the shell enables the surface plasmon resona...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Synthesis and Single‐Particle Optical Detection of Low‐Polydispersity Plasmonic‐Superparamagnetic Nanoparticles

et al. 2008

View full text Add to dashboard Cite

show abstract

“…The gold Electro-less plating reactions will only form on the sputtered gold seed layer. Electro-less plating [29] was accomplished in 50 mM pH 7.0 phosphate buffer containing 1.6 mM sodium gold (I) thiosulfate and 2.68 mM ascorbic acid. The reaction is given by

\begin{matrix} left \\ {normalC}_{6} {normalH}_{8} {normalO}_{6} \to {normalC}_{6} {normalH}_{6} {normalO}_{6} + 2 {normale}^{­} + 2 {normalH}^{+} \\ Au {({normalS}_{2} {normalO}_{3})}_{2}^{3 ­} + {normale}^{­} ⇌ Au + 2 {normalS}_{2} {normalO}_{3}^{2 ­} \end{matrix}

…”

Section: Methodsmentioning

confidence: 99%

“…The gold Electro-less plating reactions will only form on the sputtered gold seed layer. Electro-less plating [ 29 ]…”

Section: Methodsmentioning

confidence: 99%

Dynamic Electrochemical Membranes for Continuous Affinity Protein Separation

Chen

Sun

et al. 2014

Adv Funct Materials

View full text Add to dashboard Cite

A membrane system with nm-scale thick electrodes is able to selectively bind genetically modified proteins and pump them across the membrane with sequential voltage pulses. The electrodes are located at the first 20nm of pore entrances to specifically capture targeted proteins and block non-specific protein transport through the pores during the binding cycle. During the release cycle, concentration of imidazole is controlled to keep the pore blocked while releasing proteins at the bottom edge of the electrode. A separation factor for GFP:BSA of 16 was achieved with observed GFP electrophoretic mobility of 2.54×10-6cm2v-1S-1. This non-optimized system with a membrane area of 0.75 cm2 has the same throughput as 1ml of commercially available chromatography columns showing viability as a continuous process. This system will enable continuous separation of expressed proteins directly from fermentation broths dramatically simplifying the separation process as well as reducing biopharmaceutical production costs.

show abstract

“…Gold (5 nm) was sputtered on the top and bottom of the AAO membranes followed by electroless plating. Electroless plating 36 was performed in 50 mM phosphate buffer, pH 7.0, containing 1.6 mM sodium gold(I) thiosulfate and 2.68 mM ascorbic acid. The oxidization and reduction reactions were given by…”

Section: Methodsmentioning

confidence: 99%

Functionalized Anodic Aluminum Oxide Membrane–Electrode System for Enzyme Immobilization

et al. 2014

View full text Add to dashboard Cite

A nanoporous membrane system with directed flow carrying reagents to sequentially attached enzymes to mimic nature’s enzyme complex system was demonstrated. Genetically modified glycosylation enzyme, OleD Loki variant, was immobilized onto nanometer-scale electrodes at the pore entrances/exits of anodic aluminum oxide membranes through His6-tag affinity binding. The enzyme activity was assessed in two reactions—a one-step “reverse” sugar nucleotide formation reaction (UDP-Glc) and a two-step sequential sugar nucleotide formation and sugar nucleotide-based glycosylation reaction. For the one-step reaction, enzyme specific activity of 6–20 min−1 on membrane supports was seen to be comparable to solution enzyme specific activity of 10 min−1. UDP-Glc production efficiencies as high as 98% were observed at a flow rate of 0.5 mL/min, at which the substrate residence time over the electrode length down pore entrances was matched to the enzyme activity rate. This flow geometry also prevented an unwanted secondary product hydrolysis reaction, as observed in the test homogeneous solution. Enzyme utilization increased by a factor of 280 compared to test homogeneous conditions due to the continuous flow of fresh substrate over the enzyme. To mimic enzyme complex systems, a two-step sequential reaction using OleD Loki enzyme was performed at membrane pore entrances then exits. After UDP-Glc formation at the entrance electrode, aglycon 4-methylumbelliferone was supplied at the exit face of the reactor, affording overall 80% glycosylation efficiency. The membrane platform showed the ability to be regenerated with purified enzyme as well as directly from expression crude, thus demonstrating a single-step immobilization and purification process.

show abstract

Electroless Gold Plating of 316 L Stainless Steel Beads

Cited by 16 publications

References 14 publications

Synthesis and Single‐Particle Optical Detection of Low‐Polydispersity Plasmonic‐Superparamagnetic Nanoparticles

Synthesis and Single‐Particle Optical Detection of Low‐Polydispersity Plasmonic‐Superparamagnetic Nanoparticles

Dynamic Electrochemical Membranes for Continuous Affinity Protein Separation

Functionalized Anodic Aluminum Oxide Membrane–Electrode System for Enzyme Immobilization

Contact Info

Product

Resources

About