scholarly journals M13 Phages Uptake of Gold Nanoparticles for Radio- and Thermal-Therapy and Contrast Imaging Improvement

2021 ◽  
Vol 11 (23) ◽  
pp. 11391
Author(s):  
Lorenzo Torrisi ◽  
Letteria Silipigni ◽  
Lubomir Kovacik ◽  
Vasily Lavrentiev ◽  
Mariapompea Cutroneo ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Laser Ablation ◽  
Metallic Nanoparticles ◽  
Average Diameter ◽  
Thermal Therapy ◽  
Low Doses ◽  
Spherical Nanoparticles ◽  
Contrast Imaging ◽  
Au Nps ◽  
Tumoral Cells

The presented work deals with the uptake of gold nanoparticles (Au NPs) by M13 phages in solutions. In particular, the Au NPs uptake modalities and their localization in the filamentous phages are evaluated and measured. Gold spherical nanoparticles (with an average diameter of the order of 10 nm) are obtained by laser ablation in water with a sodium citrated surfactant. The interest of such application comes from the possibility to employ living biological structures to transport heavy metallic nanoparticles inside cells of tumoral tissues. Indeed, phages have the capability to introduce Au NPs in the proximity to the cell nucleus, increasing the efficiency of DNA destruction in the tumoral cells by employing low doses of ionizing radiation during radiotherapy and hyperthermia treatments. Several analyses and microscopy characterizations of the prepared phages samples embedding gold nanoparticles are presented, demonstrating that the presence of Au NPs increases the phages imaging contrast.

scholarly journals The Physical Properties and Applications of Gold Nanoparticles (Au NPs): Review

2021 ◽  
Vol 3 (1) ◽  
pp. 74-86
Author(s):  
Rusul Adnan Al-wardy . ◽  
Saad Khalid Rahi .
Keyword(s):  
Drug Delivery ◽  
Quantum Dots ◽  
Gold Nanoparticles ◽  
Physical Properties ◽  
Current Work ◽  
Spherical Nanoparticles ◽  
Au Nps ◽  
3 Dimensional ◽  
Nano Rods ◽  
Catalytic Applications

Nanoparticles of gold that for years have been recognized are the concept of an increasingly rising reports number and of promising for electronic, optical, magnetic, biomedical and catalytic applications in century of 21st. Because of Nanoparticles of gold stability, an interest in such research is a reason for performing the current work. There are various types of AuNPs: Zero-dimensional AuNps: quantum dots, spherical nanoparticles. AuNPs as 1-dimensional: nanowires, nano-rods, nano-belts, nanotubes. AuNPs as 2-dimensional: nano-plates of gold, nano-shell and, AuNPs as 3 dimensional: nano tadpoles of gold, nano- dumbbells of gold (AuNDs), AuNPs being spread, for example, nano-dendrites of gold, nano-pods, and nano-stars. Au NPs, in the field of medicine are investigated for several applications include vectors of drug delivery, agents of contrast, and therapy of localized heat, biomarkers of ultra-sensitive and more. AuNPs are very attractive material for biosensor, chemosensory, genosensor and immunosensor production

Green Synthesis of Gold Nanoparticles Using Longan Polysaccharide and their Reduction of 4-nitrophenol and Biological Applications

NANO ◽  
2020 ◽  
Vol 15 (01) ◽  
pp. 2050002 ◽  
Author(s):  
Xiaoyu Zhang ◽  
Liyuan Fan ◽  
Yanshuai Cui ◽  
Tianming Cui ◽  
Shengfu Chen ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Green Synthesis ◽  
Metallic Nanoparticles ◽  
High Catalytic Activity ◽  
Synthetic Method ◽  
Biological Applications ◽  
Au Nps ◽  
Stabilizing Agents ◽  
Highly Dispersed ◽  
Negative Zeta Potential

The green synthesis of gold nanoparticles (Au NPs) for catalytic and biological applications has been drawing great attention. To compare with plant extracts, the polysaccharides may be good reducing and stabilizing agents. In this work, we describe the preparation of longan polysaccharide stabilized gold nanoparticles (Aun-LP NPs) by reduction of gold ions using a green synthetic method. The formation of gold nanoparticles (Au NPs) was confirmed by UV-Vis spectra. TEM showed that Au NPs had a small size (7.8–15.6[Formula: see text]nm) and were highly dispersed without any aggregation. XPS confirmed that the surface elemental composition of Aun-LP NPs was C, O, and Au. DLS demonstrated that Aun-LP NPs had good stability and negative zeta potential. In addition, Aun-LP NPs had high catalytic activity for the reduction of 4-nitrophenol. More importantly, Aun-LP NPs had ignorable cytotoxicity towards HeLa cells and showed good antioxidant activity. Taken together, the results indicated that longan polysaccharide can be used as reducing agents and stabilizers for the preparation of metallic nanoparticles, and the product had wide applications.

scholarly journals Biosynthesis of Silver and Gold Nanoparticles Using Aqueous Extract from Crinum latifolium Leaf and Their Applications Forward Antibacterial Effect and Wastewater Treatment

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Thanh-Truc Vo ◽  
Thi Thanh-Ngan Nguyen ◽  
Thi Thanh-Tam Huynh ◽  
Thi Thuy-Trang Vo ◽  
Thi Thuy-Nhung Nguyen ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Aqueous Extract ◽  
Metallic Nanoparticles ◽  
Antibacterial Effect ◽  
Average Diameter ◽  
Catalytic Performance ◽  
Biologically Active ◽  
Bacterial Strains ◽  
Uv Visible ◽  
Average Size

Crinum latifolium (CL) leaf is a source of various biologically active compounds such as alkaloid and phenolic compounds, which exhibit anti-inflammatory, antitumor, and antimicrobial effects. In the purpose of expanding applications for the field of bionanotechnology, we report biosynthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) by using aqueous extract from C. latifolium leaf and explore antibacterial activity and catalytic performance for degradation of pollutants. The formation of CL-AgNPs and CL-AuNPs is confirmed and optimized by UV-visible spectroscopy with surface plasmon resonance (SPR) peaks at around 402 and 539 nm, respectively. The spherical CL-AgNPs have an average diameter of 20.5 nm and the multishaped CL-AuNPs possess an average size of 17.6 nm. The actions of four bacterial strains were strongly inhibited by using the CL-AgNPs. Furthermore, the biosynthesized metallic nanoparticles (MNPs) exhibited the excellent catalytic degradation performance of pollutants.

One-Step Femtosecond Laser Ablation Synthesis of Sub-5 Nm Gold Nanoparticles Embedded in Silica

2018 ◽  
Author(s):  
Mallory John ◽  
Katharine Moore Tibbetts
Keyword(s):  
Gold Nanoparticles ◽  
Laser Ablation ◽  
Laser Pulse ◽  
Femtosecond Laser ◽  
Silicon Wafer ◽  
Femtosecond Laser Pulses ◽  
Silica Matrix ◽  
Au Nps ◽  
One Step ◽  
Two Populations

<div> <div> <div> <p>We report the synthesis of silica-gold nanoparticles (silica-Au NPs) using a one-step femtosecond-reactive laser ablation in liquid (fs-RLAL) technique by focusing femtosecond laser pulses onto a silicon wafer immersed in an aqueous KAuCl4 solution. Characterization of the silica-Au NPs revealed two populations of Au NPs: (i) larger, isolated Au NPs with diameter 7.3±2.1 nm, and (ii) smaller Au NPs (3.4±0.8 nm) embedded in an amorphous silica matrix, along with new species of silicon observed from XPS analysis. The catalytic activity of the silica-Au NPs towards the reduction of para-nitrophenol by NaBH4 is significantly higher compared to the control Au NPs synthesized in the absence of a silicon wafer and other Au NPs recently reported in literature. The formation of the two populations of silica-Au NPs is ascribed to reaction dynamics occurring on two distinct timescales. First, the dense electron plasma formed within tens of femtoseconds of the laser pulse initiates reduction of the [AuCl4]– complex, leading to the formation of larger isolated Au NPs. Second, silicon species ejected from the wafer surface hundreds of picoseconds or later after the initial laser pulse reduce the remaining [AuCl4 ]– and encapsulate the growing clusters, forming ultrasmall Au NPs embedded in the silica matrix. The morphologies of the silica-Au NPs generated from fs-RLAL are distinct from those reported in recent RLAL experiments with nanosecond lasers, reflecting distinct mechanisms occurring on the different pulse duration timescales. </p> </div> </div> </div>

scholarly journals Synthesis of Porous Polydimethylsiloxane Gold Nanoparticles Composites by a Single Step Laser Ablation Process

2021 ◽  
Vol 22 (22) ◽  
pp. 12155
Author(s):  
Mariapompea Cutroneo ◽  
Vladimir Havranek ◽  
Anna Mackova ◽  
Petr Malinsky ◽  
Letteria Silipigni ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Laser Ablation ◽  
Au Nanoparticles ◽  
Metal Salt ◽  
Single Step ◽  
Curing Agent ◽  
Step Method ◽  
Au Nps ◽  
Liquid Polymer ◽  
Vis Spectroscopy

Typically, polymeric composites containing nanoparticles are realized by incorporating pre-made nanoparticles into a polymer matrix by using blending solvent or by the reduction of metal salt dispersed in the polymeric matrix. Generally, the production of pre-made Au NPs occurs in liquids with two-step processes: producing the gold nanoparticles first and then adding them to the liquid polymer. A reproducible method to synthetize Au nanoparticles (NPs) into polydimethylsiloxane (PDMS) without any external reducing or stabilizing agent is a challenge. In this paper, a single-step method is proposed to synthetize nanoparticles (NPs) and at the same time to realize reproducible porous and bulk composites using laser ablation in liquid. With this single-step process, the gold nanoparticles are therefore produced directly in the liquid polymer. The optical properties of the suspensions of AuNPs in distilled water and in the curing agent have been analyzed by the UV-VIS spectroscopy, employed in the transmission mode, and compared with those of the pure curing agent. The electrical dc conductivity of the porous PDMS/Au NPs nanocomposites has been evaluated by the I–V characteristics. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis have monitored the composition and morphology of the so-obtained composites and the size of the fabricated Au nanoparticles. Atomic force microscopy (AFM) has been used to determine the roughness of the bulk PDMS and its Au NP composites.

One-Step Femtosecond Laser Ablation Synthesis of Sub-5 Nm Gold Nanoparticles Embedded in Silica

2018 ◽  
Author(s):  
Mallory John ◽  
Katharine Moore Tibbetts
Keyword(s):  
Gold Nanoparticles ◽  
Laser Ablation ◽  
Laser Pulse ◽  
Femtosecond Laser ◽  
Silicon Wafer ◽  
Femtosecond Laser Pulses ◽  
Silica Matrix ◽  
Au Nps ◽  
One Step ◽  
Two Populations

<div> <div> <div> <p>We report the synthesis of silica-gold nanoparticles (silica-Au NPs) using a one-step femtosecond-reactive laser ablation in liquid (fs-RLAL) technique by focusing femtosecond laser pulses onto a silicon wafer immersed in an aqueous KAuCl4 solution. Characterization of the silica-Au NPs revealed two populations of Au NPs: (i) larger, isolated Au NPs with diameter 7.3±2.1 nm, and (ii) smaller Au NPs (3.4±0.8 nm) embedded in an amorphous silica matrix, along with new species of silicon observed from XPS analysis. The catalytic activity of the silica-Au NPs towards the reduction of para-nitrophenol by NaBH4 is significantly higher compared to the control Au NPs synthesized in the absence of a silicon wafer and other Au NPs recently reported in literature. The formation of the two populations of silica-Au NPs is ascribed to reaction dynamics occurring on two distinct timescales. First, the dense electron plasma formed within tens of femtoseconds of the laser pulse initiates reduction of the [AuCl4]– complex, leading to the formation of larger isolated Au NPs. Second, silicon species ejected from the wafer surface hundreds of picoseconds or later after the initial laser pulse reduce the remaining [AuCl4 ]– and encapsulate the growing clusters, forming ultrasmall Au NPs embedded in the silica matrix. The morphologies of the silica-Au NPs generated from fs-RLAL are distinct from those reported in recent RLAL experiments with nanosecond lasers, reflecting distinct mechanisms occurring on the different pulse duration timescales. </p> </div> </div> </div>

Size Reduction of Gold Nanoparticles by Pulsed Laser Ablation and Re-Irradiation in Water Media

2011 ◽  
Vol 695 ◽  
pp. 174-177 ◽  
Author(s):  
Pichitchai Pimpang ◽  
Duangmanee Wongratanaphisan ◽  
Atcharawan Gardchareon ◽  
Supab Choopun
Keyword(s):  
Gold Nanoparticles ◽  
Laser Ablation ◽  
Zeta Potential ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Size Reduction ◽  
Au Nps ◽  
Vis Spectroscopy ◽  
Water Media ◽  
Cover Slide

Gold nanoparticles (Au NPs) were prepared by using pulsed laser ablation with and without cover slide. The cover slide was used to confine atoms/ions in order to reach supersaturation condition. The obtained Au NPs were investigated by UV-vis spectroscopy, transmission electron microscopy (TEM), and zeta potential measurement. The absorbance spectra exhibited its absorption peak at around 520 nm for both Au NPs ablating with and without cover slide. It was found that Au NPs ablating with cover slide exhibited smaller size and size distribution (10.6 ± 5.9 nm) than those of without cover slide (34.1 ± 21.5 nm) at laser power of 5.00 mJ/pulse. This is due to supersaturation effect and re-irradiation effect caused by cover slide that trapped atoms/ions of gold and trapped Au NPs, respectively. Also, the zeta potential of Au NPs had a negative value suggesting negative surface charge. The lowest zeta potential was observed for Au NPs ablating with cover slide at 5.00 mJ/pulse and it was in consistent with an observation of the highest pH value. In addition, the Au NPs ablating with cover slide at 5.00 mJ/pulse showed the least change with time indicating the most stable Au NPs which was in consistent with the lowest zeta potential results. Thus, pulsed laser re-irradiation could be used for size reduction of Au NPs prepared by pulsed laser ablation in water media.

scholarly journals Easy and fast in-situ functionalization of exfoliated 2D black phosphorus with gold nanoparticles

2021 ◽  
Author(s):  
Salvatore Moschetto ◽  
Andrea Ienco ◽  
Gabriele Manca ◽  
Manuel Serrano-Ruiz ◽  
Maurizio Peruzzini ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Black Phosphorus ◽  
Au Nps ◽  
In Situ Functionalization

Heterostructures of single- and few-layer black phosphorus (2D bP) functionalized with gold nanoparticles (Au NPs) have been recently reported in the literature, exploiting their intriguing properties and biocompatibility for catalytic,...

scholarly journals Continuous citrate‐capped gold nanoparticle synthesis in a two‐phase flow reactor

2021 ◽  
Author(s):  
Spyridon Damilos ◽  
Ioannis Alissandratos ◽  
Luca Panariello ◽  
Anand N. P. Radhakrishnan ◽  
Enhong Cao ◽  
...  
Keyword(s):  
Particle Size ◽  
Gold Nanoparticles ◽  
Residence Time ◽  
Flow Reactor ◽  
Phase Flow ◽  
Continuous Manufacturing ◽  
Two Phase ◽  
Process Yield ◽  
Au Nps ◽  
Manufacturing Platform

AbstractA continuous manufacturing platform was developed for the synthesis of aqueous colloidal 10–20 nm gold nanoparticles (Au NPs) in a flow reactor using chloroauric acid, sodium citrate and citric acid at 95 oC and 2.3 bar(a) pressure. The use of a two-phase flow system – using heptane as the continuous phase – prevented fouling on the reactor walls, while improving the residence time distribution. Continuous syntheses for up to 2 h demonstrated its potential application for continuous manufacturing, while live quality control was established using online UV-Vis photospectrometry that monitored the particle size and process yield. The synthesis was stable and reproducible over time for gold precursor concentration above 0.23 mM (after mixing), resulting in average particle size between 12 and 15 nm. A hydrophobic membrane separator provided successful separation of the aqueous and organic phases and collection of colloidal Au NPs in flow. Process yield increased at higher inlet flow rates (from 70 % to almost 100 %), due to lower residence time of the colloidal solution in the separator resulting in less fouling in the PTFE membrane. This study addresses the challenges for the translation of the synthesis from batch to flow and provides tools for the development of a continuous manufacturing platform for gold nanoparticles.Graphical abstract

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