scholarly journals Detection of Inorganic and Metal Nanoparticles using qNano – IZON Science’s Nanoparticle Analysis System

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>

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>


2021 ◽  
pp. 000370282110420
Author(s):  
Per Samuelsson ◽  
Markus Snellman ◽  
Martin H. Magnusson ◽  
Knut Deppert ◽  
Marcus Aldén ◽  
...  

We report the observation of photoluminescence emission from airborne gold, silver, and copper nanoparticles. A continuous wave 532 nm laser was employed for excitation. Photoluminescence from gold nanoparticles carried in a nitrogen gas flow was both spectrally resolved and directly imaged in situ using an intensified charge-coupled device camera. The simultaneously detected Raman signal from the nitrogen molecules enables quantitative estimation of the photoluminescence quantum yield of the gold nanoparticles. Photoluminescence from metal nanoparticles carried in a gas flow provides a potential tool for operando imaging of plasmonic metal nanoparticles in aerosol reactions.


Author(s):  
Hyuk-Mi Lee ◽  
Hwan-Goo Kang

AbstractTo develop a new simple and simultaneous purification method for mycotoxins in feeds and grains, magnetic nanoparticles (MNPs) conjugated with monoclonal antibodies (mAbs) against mycotoxins were used to separate aflatoxin B1 (AFB1), zearalenone (ZEA) and deoxynivalenol (DON). For a single spike of each mycotoxin into the buffer solution (16% MeOH in PBS), mean recoveries were 93.1–95.0% for AFB1 (5–20 ng/mL spiked), 87.2–96.0% for ZEA (125–500 ng/mL spiked) and 75.2–96.9% for DON (250–1,000 ng/mL spiked) by HPLC and ELISA. Recoveries of AFB1 (20 ng/mL) and ZEA (500 ng/mL) simultaneously spiked into the buffer solution were 87.0 and 99.8%, respectively. Recovery rates of AFB1/DON and DON/ZEA spiked simultaneously were 86.2%/76.6% and 92.0%/86.7%, respectively, at concentrations of 20 ng/mL AFB1, 500 ng/mL ZEA, and 1,000 ng/mL DON. Recoveries using the novel mAb–MNP conjugated system in a buffer solution simultaneously spiked with AFB1, ZEA and DON were 82.5, 94.6 and 73.4%, respectively. Recoveries of DON in animal feed were 107.7–132.5% at concentrations of 250–1,000 ng/g spiked in feed. The immunoaffinity chromatography (IAC) clean-up method was compared with the purification method using novel mAb–MNP. After fortification of animal feed with AFB1 (5, 10 and 20 ng/g feed) and ZEA (125, 250 and 500 ng/g feed), AFB1 and ZEA were purified using both the methods. In the case of the novel mAb-MNP conjugated system, mean recoveries for AFB1 were 89.4, 73.1 and 88.3% at concentrations of 5, 10 and 20 ng/g feed, respectively. For ZEA, mean recoveries were 86.7, 85.9 and 79.1% at concentrations of 125, 250 and 500 ng/g, respectively. For IAC purification, recoveries were 42.9–45.1% for AFB1 and 96.8–103.2% for ZEA. In conclusion, the present purification method using monoclonal antibodies conjugated to MNPs can be used for simple and simultaneous purification of mycotoxins from feed and maize.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 312
Author(s):  
Mohammad Okkeh ◽  
Nora Bloise ◽  
Elisa Restivo ◽  
Lorenzo De Vita ◽  
Piersandro Pallavicini ◽  
...  

In 2017 the World Health Organization (WHO) announced a list of the 12 multidrug-resistant (MDR) families of bacteria that pose the greatest threat to human health, and recommended that new measures should be taken to promote the development of new therapies against these superbugs. Few antibiotics have been developed in the last two decades. Part of this slow progression can be attributed to the surge in the resistance acquired by bacteria, which is holding back pharma companies from taking the risk to invest in new antibiotic entities. With limited antibiotic options and an escalating bacterial resistance there is an urgent need to explore alternative ways of meeting this global challenge. The field of medical nanotechnology has emerged as an innovative and a powerful tool for treating some of the most complicated health conditions. Different inorganic nanomaterials including gold, silver, and others have showed potential antibacterial efficacies. Interestingly, gold nanoparticles (AuNPs) have gained specific attention, due to their biocompatibility, ease of surface functionalization, and their optical properties. In this review, we will focus on the latest research, done in the field of antibacterial gold nanoparticles; by discussing the mechanisms of action, antibacterial efficacies, and future implementations of these innovative antibacterial systems.


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.


Author(s):  
Anna Malec ◽  
Christoph Haiden ◽  
Georgios Kokkinis ◽  
Ioanna Giouroudi

In this paper, we present a method for detecting and quantifying pathogens in water samples. The method proposes a portable dark field imaging and analysis system for quantifying E. coli concentrations in water after being labeled with magnetic particles. The system utilizes the tracking of moving micro/nano objects close to or below the optical resolution limit confined in small sample volumes (~ 10 µl). In particular, the system analyzes the effect of volumetric changes due to bacteria conjugation to magnetic microparticles (MP) on their Brownian motion while being suspended in liquid buffer solution. The method allows for a simple inexpensive implementation and the possibility to be used as point-of-need testing system. Indeed, a work-ing prototype is demonstrated with the capacity of quantifying E. coli colony forming units (CFU) at a range of 1x10³ - 6x10³ CFU/mL.


2015 ◽  
Vol 15 (3) ◽  
pp. 226-233 ◽  
Author(s):  
Fitriyana Fitriyana ◽  
Fredy Kurniawan

Sucrose sensor has been made by deposited the active materials on the surface of gold electrode. The active materials, i.e. polyaniline (PANI), invertase and gold nanoparticles, were deposited step by step. Aniline polymerization were conducted electrochemically at potential -500 to 1000 mV using voltammetry method with sweep rate 50 mV/s for 20 cycles in HCl solution pH 1.5. The modified electrode obtained was immersed in invertase 1 M phosphate buffer solution pH 6. The invertase trapping in polyaniline was performed using the same condition as aniline polymerization. Then, gold nanoparticles were deposited on the polyaniline-invertase modified gold electrode using Layer by Layer (LbL) technique. The polyaniline-invertase-gold nanoparticles modified gold electrode obtained was used to measure sucrose solution. Electrochemical signal of polyaniline (PANI)-invertase-gold nanoparticles modified gold electrode is increase with sucrose concentration. The sensitivity and detection limit of the electrode are 0.4657 µA mm-2 mM-1 and 9 µM, respectively. No electrochemical interference signals from fructose and glucose have been observed in the sucrose measurement.


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.


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.


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