N-Heterocyclic carbene-ended polymers as surface ligands of plasmonic metal nanoparticles

2020 ◽  
Vol 8 (7) ◽  
pp. 2280-2288 ◽  
Author(s):  
Srinivas Thanneeru ◽  
Kaitlynn M. Ayers ◽  
Murali Anuganti ◽  
Lei Zhang ◽  
Challa V. Kumar ◽  
...  

A facile methodology to prepare N-heterocyclic carbene (NHC)-terminated polymers as surface ligands to functionalize gold nanoparticles (AuNPs) is reported.

Langmuir ◽  
2016 ◽  
Vol 32 (6) ◽  
pp. 1601-1610 ◽  
Author(s):  
Jinhong Gao ◽  
Ouyang Zhang ◽  
Jing Ren ◽  
Chuanliu Wu ◽  
Yibing Zhao

Author(s):  
Evan S. Glazer ◽  
Warna D. Kaluarachchi ◽  
Steven A. Curley

Noninvasive radiofrequency (RF) fields heat metal nanoparticles in a concentration dependent fashion. Gold nanoparticles are especially interesting for biomedical applications because they not only heat well, but they have an established biosafety profile. Antibody-targeted gold nanoparticles have been used to induce hyperthermic cytotoxicity when exposed to RF fields. Two carcinoma cells lines, Panc-1 and Hep3B, were individually treated with 100 nM panitumumab and trastuzumab antibody conjugated 10 nm gold nanoparticles and subsequently exposed to an RF field for a total generator power of ∼100 kJ. Two days later, control cells treated with antibody labeled gold nanoparticles, but not exposed to the RF field, maintained an average viability of 92.1% ± 2.5% for Hep 3B cells and 89.1% ± 2.1% for Panc-1 cells based on flow cytometry. Panc-1 cells treated the same way with subsequent RF field exposure had viability less than 80% (p ∼ 0.001). Hep3B cells showed a similar decrease in viability after trastuzumab-gold treatment (74.5% ± 6.9%), but not panitumumab. This demonstrates a new and developing use of antibodies, specifically, against EGFR family targets.


2020 ◽  
Vol 4 (2) ◽  

Metal nanoparticles possess an extensive scientific and technological significance due to their unique physiochemical properties and their potential applications in different fields like medicine. Silver and gold nanoparticles have shown to have antibacterial and cytotoxic activities. Conventional methods used in the synthesis of the metal nanoparticles involve use of toxic chemicals making them unsuitable for use in medical field. In our continued effort to explore for simple and eco-friendly methods to synthesize the metal nanoparticles, we here describe synthesis and characterization of gold and silver nanoparticles using Gonaderma lucidum, wild non-edible medicinal mushroom. G. lucidum mushroom contain bioactive compounds which can be involved in the reduction, capping and stabilization of the nanoparticles. Antibacterial activity analysis was done on E. coli and S. aureus. The synthesis was done on ultrasonic bath. Characterization of the metal nanoparticles was done by UV-VIS., High Resolution Transmission Electron Microscope (HRTEM) and FTIR. HRTEM analysis showed that both silver and gold nanoparticles were spherical in shape with an average size of 15.82±3.69 nm for silver and 24.73±5.124nm for gold nanoparticles (AuNPs). FTIR analysis showed OH and -C=C- stretching vibrations, an indication of presence of functional groups of biomolecules capping both gold and silver nanoparticles. AgNPs showed inhibition zones of 15.5±0.09mm and 13.3±0.14mm while AuNPs had inhibition zones of 14.510±0.35 and 13.3±0.50mm on E. coli and S. aureus respectively. The findings indicate the potential use of AgNPs and AuNPs in development of drugs in management of pathogenic bacteria.


Langmuir ◽  
2018 ◽  
Vol 34 (41) ◽  
pp. 12445-12451 ◽  
Author(s):  
Jinjian Wei ◽  
Hideyuki Mitomo ◽  
Takeharu Tani ◽  
Yasutaka Matsuo ◽  
Kenichi Niikura ◽  
...  

2020 ◽  
Vol 64 ◽  
pp. 105-114
Author(s):  
Abdurrahman Taha Gülderen ◽  
Yasemin Oztekin

Herein, this study shows three different synthesis of gold nanoparticles with various nano-shapes and an investigation of the correlation between nano-shapes and electrochemical effects on dopamine oxidation. To synthesize nano-shaped gold nanoparticles green reducing sources such as rose extract, glucose, and pomegranate juice were used. Thereby, three different gold nanoparticles were synthesized. In order to examine nanoparticle shapes microscopic and spectroscopic characterizations of nanoparticles were carried out. Subsequently the effects of shapes on electrochemical probes and dopamine were accomplished. As a result, it was confirmed that the shapes of the same metal nanoparticles had different effects on electrochemical experiments.


2016 ◽  
Vol 314 ◽  
pp. 188-196 ◽  
Author(s):  
Hongying Li ◽  
Xinxin Ye ◽  
Xisheng Guo ◽  
Zhigang Geng ◽  
Guozhong Wang

Nano LIFE ◽  
2016 ◽  
Vol 06 (02) ◽  
pp. 1642001 ◽  
Author(s):  
Xinjun Yu ◽  
Yang Jiao ◽  
Qinyuan Chai

Gold nanoparticles (AuNPs) as one of the most stable metal nanoparticles have demonstrated extensive applications in recent years. This paper will give a focus on the AuNPs as biosensors, due to their inertness, unique optical properties, high surface area, and various surface functionalization methods. Synthesis of AuNps and the surface functionalization will be discussed in the first part. The size, shape, and stability can be controlled by different synthetic methods, while reductant usually needed. By surface functionalization with different molecules such as polymers, nucleic acids, and proteins, AuNPs will aggregate when specified molecule linkages showing up enables selective detections. The application in biosensing to detect proteins, oligonucleotide, glucose, and heavy metals will be exemplified, followed by the summary and future perspective part in the conclusion.


2021 ◽  
Author(s):  
◽  
Nadiah Ali

<p>This thesis investigates the potential and capability of the qNano instrument, a nanoparticle analysis research instrument developed by IZON Science Ltd. The qNano operates on the basis of the Scanning Ion Occlusion Spectroscopy (SIOS) technology which is similar to the Coulter technique also known as resistive pulse sensing. This coupled with an adjustable nanopore and IZON’s recently developed Variable Pressure Module (VPM) makes qNano a versatile nanoparticle analysis apparatus. In this study the potential of the instrument to detect inorganic and metal nanoparticles is explored. Polystyrene, silica, gold, silver, and magnetic nanoparticles have been used in this research to better understand the system and its components and to discover the capacity of the instrument to detect these particles. Using polystyrene nanoparticles, it was found that the adjustable nanopore exhibit membrane softening and follows the Mullins effect. Each of the apertures also possesses a characteristic window of operation, which refers to a range of stretch setting for accurate particle detection. The adjustable nanopore also allows for sizing particles with different diameters. The effect of surface functionality in the signal output was also investigated. Gold nanoparticles were synthesized via the citrate reduction method and the study of gold nanoparticles suspended in IZON’s standard buffer solution was looked into in depth. It was found that the gold nanoparticles aggregate in the buffer solution due to the presence of potassium chloride (KCl) salt which screens the electrostatic stabilization provided by the citrate ions. Silver nanoparticles show similar aggregation. With the concentration of gold and KCl remaining constant, resistive pulses caused by gold aggregates were detected after a period of three hours. Varying the concentration of gold nanoparticles shows that larger aggregates are formed as opposed to small aggregates with higher population. Identification of different types of particles present in a solution is yet to be achieved at this stage. Silica and magnetic nanoparticles were studied briefly. Successful measurements of magnetic particles were achieved with the aid of the pressure module. However, aggregates of magnetic particles were also formed and can be seen with the naked eye after solution was left standing overnight. Casein stabilized silica particles shows erratic current readings as the ethanol used in fabricating the silica particles collapse the casein micelle structure thus making the stabilization by casein void. Overall, this thesis has shown the qNano instrument’s ability in detecting nanoparticles other than biological molecules. This thesis also shows the potential of qNano as a versatile research instrument. The prospect of further research using this instrument is tremendous especially in characterising in greater detail inorganic and metal nanoparticles.</p>


Author(s):  
Rama Sharma ◽  
Hariom Gupta

Background: Terminalia arjuna has many biological applications and their metal nanoparticles have no hazardous effect on the environment. We have demonstrated that Terminalia arjuna bark mediated metal nanoparticles can be used to enhance the germination of seeds. Methods: To evaluate the effect on germination we treated Vigna unguiculata (black eyed peas) seeds with copper, silver and gold nanoparticles synthesized by Terminalia arjuna bark. The synthesized metal nanoparticles were characterized by UVspectroscopy and size was confirmed by diffraction light scattering technique. Results: After incubation of 48 hours, the effects were observed. It was observed that Vigna unguiculata (black eyed peas) seed showed 30% germination in silver nanoparticles solution and 70% in copper nanoparticles, 0% was observed in gold nanoparticles. Conclusions: The results obtained in the study showed the relevance of nanobiotechnology in agriculture to boost the production of crops.


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