scholarly journals Selective shortening of gold nanorods: when surface functionalization dictates the reactivity of nanostructures

Nanoscale ◽  
2020 ◽  
Vol 12 (44) ◽  
pp. 22658-22667
Author(s):  
Abdelali Khelfa ◽  
Jun Meng ◽  
Caroline Byun ◽  
Guillaume Wang ◽  
Jaysen Nelayah ◽  
...  
Keyword(s):  
Surface Functionalization ◽  
Gold Nanorods ◽  
Degradation Kinetics ◽  
Capping Agents

We reveal how degradation kinetics and capping agents drive the selective shortening of gold nanorods in oxidative media.

scholarly journals Polydopamine-enabled surface functionalization of gold nanorods for cancer cell-targeted imaging and photothermal therapy

Nanomedicine ◽  
2013 ◽  
Vol 8 (1) ◽  
pp. 17-28 ◽  
Author(s):  
Kvar CL Black ◽  
Ji Yi ◽  
José G Rivera ◽  
Daria C Zelasko-Leon ◽  
Phillip B Messersmith
Keyword(s):  
Cancer Cell ◽  
Surface Functionalization ◽  
Gold Nanorods ◽  
Photothermal Therapy ◽  
Targeted Imaging

scholarly journals Gold Nanorods Capped with Different Ammonium Bromide Salts on the Catalytic Chemical Reduction of p-Nitrophenol

2021 ◽  
Author(s):  
Francyelle de Oliveira ◽  
Lucas Nascimento ◽  
Claudia Calado ◽  
Simoni Meneghetti ◽  
Monique da Silva ◽  
...  
Keyword(s):  
Gold Nanorods ◽  
Chemical Reduction ◽  
Ammonium Bromide ◽  
Capping Agent ◽  
Catalytic Systems ◽  
Capping Agents ◽  
Tetraalkylammonium Bromide ◽  
Transmission Electron ◽  
Particle Size And Shape ◽  
Induction Times

It is known that the reactivity of the nanocatalytic systems is related to the particle size and shape and also to the features of the capping agents on the nanostructures. In this study, gold nanorods (AuNRs) were synthesized by the seed-mediated method using different tetraalkylammonium bromide salts as capping agents, that are, cetyltrimethylammonium (CTABr), N,N-dimethyl-N‑cetyl-N-(2-hydroxyethyl)ammonium (HEA16Br), and N,N-dimethyl-N-cetyl- N-(2-hydroxypropyl)ammonium (HPA16Br), and used as catalyst for the chemical reduction of p-nitrophenol (PNP) in the presence of NaBH4. The catalytic systems were characterized by ultraviolet-visible (UV-Vis) absorption spectroscopy and transmission electron microscopy (TEM). The effect of the ammonium bromide-based capping agent on the catalytic activity of AuNRs was evaluated by performing the chemical reduction of p-nitrophenol in the presence of excess NaBH4 in aqueous medium. Under the reaction conditions employed, the catalytic systems displayed detectable subtle differences in terms of induction times and apparent activation energy (Ea) values. These results show that slight changes carried out in the chemical structure of the capping agent are able to imprint even slightly modification of the kinetic parameter of the catalytic reaction.

scholarly journals Altering the Biodegradation of Mesoporous Silica Nanoparticles by Means of Experimental Parameters and Surface Functionalization

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Stephanie Seré ◽  
Bert De Roo ◽  
Mattias Vervaele ◽  
Stefaan Van Gool ◽  
Sandra Jacobs ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Surface Functionalization ◽  
Degradation Kinetics ◽  
Mesoporous Silica Nanoparticles ◽  
Degradation Behavior ◽  
Molybdenum Blue ◽  
Nanoparticle Growth ◽  
Degraded Material ◽  
Synthesis Procedure

Mesoporous silica nanoparticles (MSNPs) are gaining a large interest in the field of medical and biomedical applications due to their biodegradability and high loading capacity as a carrier. In this work, a simple synthesis and functionalization procedure is reported, which allows tuning the nanoparticle properties, functionalization, and biodegradability. Variations in the synthesis procedure are introduced, including temperature, concentration of catalyst, and surface functionalization. These samples are characterized and afterwards degraded in phosphate buffered saline (PBS) to determine their degradation kinetics. The amount of degraded material is colorimetrically determined, using an optimized protocol based on molybdenum blue chemistry. It is shown that the degradability of the nanoparticles increased with decreasing synthesis temperatures, lower amounts of catalyst, and higher concentrations of nanoparticles. Surface functionalization alters the degradation kinetics as well, rendering amino-functionalized nanoparticles the fastest degradation behavior, followed by carboxylated and nonfunctionalized nanoparticles. From these results, it can be concluded that the degradation rate of MSNPs can be varied from a few hours to several days by small changes in the synthesis procedure. Moreover, the degradation behavior is strongly dependent on the nanoparticle growth rate.

scholarly journals Development of amyloid beta gold nanorod aggregates as optoacoustic probes

2021 ◽  
Author(s):  
Mahmoud G Soliman ◽  
Hannah A Davies ◽  
Jack Sharkey ◽  
Raphaël Lévy ◽  
Jillian Madine
Keyword(s):  
Amyloid Beta ◽  
Surface Functionalization ◽  
Gold Nanorods ◽  
Neuroblastoma Cells ◽  
Potential Mechanism ◽  
Biophysical Properties ◽  
Optoacoustic Imaging ◽  
Optoacoustic Tomography ◽  
Vis Spectroscopy

Propagation of small amyloid beta (Aβ) aggregates (or seeds) has been suggested as a potential mechanism of Alzheimer’s disease progression. Monitoring the propagation of Aβ seeds in an organism would enable testing of this hypothesis and, if confirmed, provide mechanistic insights. This requires a contrast agent for long-term tracking of the seeds. Gold nanorods combine several attractive features for this challenging task, in particular, their strong absorbance in the infrared (enabling optoacoustic imaging) and the availability of several established protocols for surface functionalization. In this work, polymer-coated gold nanorods were conjugated with anti-Aβ antibodies and specifically attached to pre-formed Aβ seeds. The resulting complexes were characterized for their optical properties by UV/Vis spectroscopy and multispectral optoacoustic tomography. The complexes retained their biophysical properties, i.e. their ability to seed Aβ fibril formation. They remained stable in biological media for at least 2 days and showed no toxicity to SH-SY5Y neuroblastoma cells up to 1.5 nM and 6 µM of gold nanorods and Aβ seeds, respectively. Taken together, this study describes the first steps in the development of probes for monitoring the spread of Aβ seeds in animal models.

scholarly journals Mechanical properties of MDCK II cells exposed to gold nanorods

2015 ◽  
Vol 6 ◽  
pp. 223-231 ◽  
Author(s):  
Anna Pietuch ◽  
Bastian Rouven Brückner ◽  
David Schneider ◽  
Marco Tarantola ◽  
Christina Rosman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Functionalization ◽  
Gold Nanorods ◽  
Cellular Response ◽  
Dark Field ◽  
Membrane Area ◽  
Gold Particles ◽  
Actin Cortex ◽  
External Stimuli ◽  
The Impact

Background: The impact of gold nanoparticles on cell viability has been extensively studied in the past. Size, shape and surface functionalization including opsonization of gold particles ranging from a few nanometers to hundreds of nanometers are among the most crucial parameters that have been focussed on. Cytoxicity of nanomaterial has been assessed by common cytotoxicity assays targeting enzymatic activity such as LDH, MTT and ECIS. So far, however, less attention has been paid to the mechanical parameters of cells exposed to gold particles, which is an important reporter on the cellular response to external stimuli. Results: Mechanical properties of confluent MDCK II cells exposed to gold nanorods as a function of surface functionalization and concentration have been explored by atomic force microscopy and quartz crystal microbalance measurements in combination with fluorescence and dark-field microscopy. Conclusion: We found that cells exposed to CTAB coated gold nanorods display a concentration-dependent stiffening that cannot be explained by the presence of CTAB alone. The stiffening results presumably from endocytosis of particles removing excess membrane area from the cell’s surface. Another aspect could be the collapse of the plasma membrane on the actin cortex. Particles coated with PEG do not show a significant change in elastic properties. This observation is consistent with QCM measurements that show a considerable drop in frequency upon administration of CTAB coated rods suggesting an increase in acoustic load corresponding to a larger stiffness (storage modulus).

scholarly journals Efficient, robust surface functionalization and stabilization of gold nanorods with quaternary ammonium-containing ionomers as multidentate macromolecular ligands

RSC Advances ◽  
2016 ◽  
Vol 6 (49) ◽  
pp. 43574-43590 ◽  
Author(s):  
Zhongmin Dong ◽  
Peng Xiang ◽  
Lingqi Huang ◽  
Zhibin Ye
Keyword(s):  
Surface Functionalization ◽  
Gold Nanorods ◽  
Quaternary Ammonium ◽  
Surface Ligands

Quaternary ammonium-containing ionomers are a novel class of multidentate macromolecular surface ligands for efficient functionalization and stabilization of gold nanorods.

Site-Specific Surface Functionalization of Gold Nanorods Using DNA Origami Clamps

2016 ◽  
Vol 138 (6) ◽  
pp. 1764-1767 ◽  
Author(s):  
Chenqi Shen ◽  
Xiang Lan ◽  
Xuxing Lu ◽  
Travis A. Meyer ◽  
Weihai Ni ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Functionalization ◽  
Gold Nanorods ◽  
Dna Origami ◽  
Site Specific

Significance of surface functionalization of Gold Nanorods for reduced effect on IgG stability and minimization of cytotoxicity

2017 ◽  
Vol 71 ◽  
pp. 744-754 ◽  
Author(s):  
Sruthi Ann Alex ◽  
Sundaramoorthy Rajiv ◽  
Sujay Chakravarty ◽  
N. Chandrasekaran ◽  
Amitava Mukherjee
Keyword(s):  
Surface Functionalization ◽  
Gold Nanorods

scholarly journals Improvement of Gold Nanorods in Photothermal Therapy: Recent Progress and Perspective

2021 ◽  
Vol 12 ◽  
Author(s):  
Shengnan Liao ◽  
Wang Yue ◽  
Shuning Cai ◽  
Quan Tang ◽  
Weitong Lu ◽  
...  
Keyword(s):  
Surface Functionalization ◽  
Gold Nanorods ◽  
Photothermal Therapy ◽  
Recent Progress ◽  
Controlled Drug Release ◽  
Synthetic Methods ◽  
Cell Uptake ◽  
Photothermal Effect ◽  
Synthesis Methods ◽  
Novel Technologies

Cancer is a life-threatening disease, and there is a significant need for novel technologies to treat cancer with an effective outcome and low toxicity. Photothermal therapy (PTT) is a noninvasive therapeutic tool that transports nanomaterials into tumors, absorbing light energy and converting it into heat, thus killing tumor cells. Gold nanorods (GNRs) have attracted widespread attention in recent years due to their unique optical and electronic properties and potential applications in biological imaging, molecular detection, and drug delivery, especially in the PTT of cancer and other diseases. This review summarizes the recent progress in the synthesis methods and surface functionalization of GNRs for PTT. The current major synthetic methods of GNRs and recently improved measures to reduce toxicity, increase yield, and control particle size and shape are first introduced, followed by various surface functionalization approaches to construct a controlled drug release system, increase cell uptake, and improve pharmacokinetics and tumor-targeting effect, thus enhancing the photothermal effect of killing the tumor. Finally, a brief outlook for the future development of GNRs modification and functionalization in PTT is proposed.

scholarly journals Surface Functionalization of Gold Nanorods Improves Nanostructure Assemblies on Amyloid Fibril Scaffolds

2020 ◽  
Vol 67 (1) ◽  
pp. 304-311
Author(s):  
Mani Salimian ◽  
Tahereh Tohidi Moghadam ◽  
Bijan Ranjbar
Keyword(s):  
Surface Functionalization ◽  
Gold Nanorods ◽  
Amyloid Fibril
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