Journal articles: 'Nanoparticle gold'

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Zhang, Liangmin. "Optical Conduction Resonance in Self-Assembled Metal Nanoparticle Array-Dielectric Thin Films." Journal of Nanomaterials 2018 (December 10, 2018): 1–9. http://dx.doi.org/10.1155/2018/8540805.

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Optical conduction resonance- (OCR-) enhanced third-order optical nonlinearity of two dimensional (2D) periodic gold nanoparticle array-dielectric thin films has been investigated. The third-order optical susceptibility of periodic gold nanoparticle array embedded in silica thin film shows ~104 enhancement comparing to gold nanoparticle colloids. The 2D gold nanoparticle arrays were synthesized by using the electrostatic self-assembly (ESA) technique. During the fabrication process, the positively or negatively functionalized gold nanoparticles are automatically self-aligned to establish a 2D array with a very small interparticle spacing due to the polymer shell on the metal particles. Then, a monolayer of silica can be coated on the top of the 2D metal nanoparticle array. This type of 2D gold nanoparticle array-dielectric thin films has high volume fraction of gold nanoparticles. According to the extended Maxwell-Garnett theory, this kind of films can exhibit OCR. The OCR frequency can be tuned from visible to mid-infrared by controlling the gold nanoparticle volume fraction. During OCR, the real part of the composite dielectric constant is zero to make the induced electromagnetic waves in gold nanoparticles to couple effectively within the film. The open-aperture z-scan technique is used to measure the nonlinear optical properties of the ESA films.

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Mat Isa, Siti Zaleha, Rafidah Zainon, and Mahbubunnabi Tamal. "State of the Art in Gold Nanoparticle Synthesisation via Pulsed Laser Ablation in Liquid and Its Characterisation for Molecular Imaging: A Review." Materials 15, no. 3 (January 24, 2022): 875. http://dx.doi.org/10.3390/ma15030875.

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With recent advances in nanotechnology, various nanomaterials have been used as drug carriers in molecular imaging for the treatment of cancer. The unique physiochemical properties and biocompatibility of gold nanoparticles have developed a breakthrough in molecular imaging, which allows exploration of gold nanoparticles in drug delivery for diagnostic purpose. The conventional gold nanoparticles synthetisation methods have limitations with chemical contaminations during the synthesisation process and the use of higher energy. Thus, various innovative approaches in gold nanoparticles synthetisation are under development. Recently, studies have been focused on the development of eco-friendly, non-toxic, cost-effective and simple gold nanoparticle synthesisation. The pulsed laser ablation in liquid (PLAL) technique is a versatile synthetic and convincing technique due to its high efficiency, eco-friendly and facile method to produce gold nanoparticle. Therefore, this study aimed to review the eco-friendly gold nanoparticle synthesisation method via the PLAL method and to characterise the gold nanoparticles properties for molecular imaging. This review paper provides new insight to understand the PLAL technique in producing gold nanoparticles and the PLAL parameters that affect gold nanoparticle properties to meet the desired needs in molecular imaging.

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Huynh, Ngoc Han, and James C. L. Chow. "DNA Dosimetry with Gold Nanoparticle Irradiated by Proton Beams: A Monte Carlo Study on Dose Enhancement." Applied Sciences 11, no. 22 (November 17, 2021): 10856. http://dx.doi.org/10.3390/app112210856.

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Heavy atom nanoparticles, such as gold nanoparticles, are proven effective radiosensitizers in radiotherapy to enhance the dose delivery for cancer treatment. This study investigated the effectiveness of cancer cell killing, involving gold nanoparticle in proton radiation, by changing the nanoparticle size, proton beam energy, and distance between the nanoparticle and DNA. Monte Carlo (MC) simulation (Geant4-DNA code) was used to determine the dose enhancement in terms of dose enhancement ratio (DER), when a gold nanoparticle is present with the DNA. With varying nanoparticle size (radius = 15–50 nm), distance between the gold nanoparticle and DNA (30–130 nm), as well as proton beam energy (0.5–25 MeV) based on the simulation model, our results showed that the DER value increases with a decrease of distance between the gold nanoparticle and DNA and a decrease of proton beam energy. The maximum DER (1.83) is achieved with a 25 nm-radius gold nanoparticle, irradiated by a 0.5 MeV proton beam and 30 nm away from the DNA.

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Yao, Cuiping, Luwei Zhang, Jing Wang, Yulu He, Jing Xin, Sijia Wang, Hao Xu, and Zhenxi Zhang. "Gold Nanoparticle Mediated Phototherapy for Cancer." Journal of Nanomaterials 2016 (2016): 1–29. http://dx.doi.org/10.1155/2016/5497136.

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Gold nanoparticles exhibit very unique physiochemical and optical properties, which now are extensively studied in range of medical diagnostic and therapeutic applications. In particular, gold nanoparticles show promise in the advancement of cancer treatments. This review will provide insights into the four different cancer treatments such as photothermal therapy, gold nanoparticle-aided photodynamic therapy, gold nanoparticle-aided radiation therapy, and their use as drug carrier. We also discuss the mechanism of every method and the adverse effects and its limitations.

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Yuan, Juan, Qing Quan Guo, Xiang Zhu He, and Yan Ping Liu. "Researching on the Adsorption of Protein on Gold Nanoparticles." Advanced Materials Research 194-196 (February 2011): 462–66. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.462.

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Because of their unique properties, gold nanoparticles(NPs) show a wide range of applications such as surface-enhanced raman characteristics, biological sensing, biomedical and other fields. Different initial concentrations of Bull Serum Albumin(BSA) and egg white lysozyme respectively react with different size of gold nanoparticles. The condition of adsorption is determined by spectrometry method, then the area of protein with different molecular mass on the surface of a gold nanoparticle is calculated. The results show that the larger particle size of a gold nanoparticle is, the more protein the surface a gold nanoparticle adsorbs; the smaller the molecular mass of protein is, the more protein is adsorbed by gold nanoparticles surface.

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Chang, Chia-Chen, Chie-Pein Chen, Tzu-Heng Wu, Ching-Hsu Yang, Chii-Wann Lin, and Chen-Yu Chen. "Gold Nanoparticle-Based Colorimetric Strategies for Chemical and Biological Sensing Applications." Nanomaterials 9, no. 6 (June 6, 2019): 861. http://dx.doi.org/10.3390/nano9060861.

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Gold nanoparticles are popularly used in biological and chemical sensors and their applications owing to their fascinating chemical, optical, and catalytic properties. Particularly, the use of gold nanoparticles is widespread in colorimetric assays because of their simple, cost-effective fabrication, and ease of use. More importantly, the gold nanoparticle sensor response is a visual change in color, which allows easy interpretation of results. Therefore, many studies of gold nanoparticle-based colorimetric methods have been reported, and some review articles published over the past years. Most reviews focus exclusively on a single gold nanoparticle-based colorimetric technique for one analyte of interest. In this review, we focus on the current developments in different colorimetric assay designs for the sensing of various chemical and biological samples. We summarize and classify the sensing strategies and mechanism analyses of gold nanoparticle-based detection. Additionally, typical examples of recently developed gold nanoparticle-based colorimetric methods and their applications in the detection of various analytes are presented and discussed comprehensively.

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Yuan, Qunying, Manjula Bomma, and Zhigang Xiao. "Enhanced Extracellular Synthesis of Gold Nanoparticles by Soluble Extracts from Escherichia coli Transformed with Rhizobium tropici Phytochelatin Synthase Gene." Metals 11, no. 3 (March 12, 2021): 472. http://dx.doi.org/10.3390/met11030472.

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Phytochelatins, the enzymatic products of phytochelatin synthase, play a principal role in protecting the plants from heavy metal and metalloid toxicity due to their ability to scavenge metal ions. In the present study, we investigated the capacity of soluble intracellular extracts from E. coli cells expressing R. tropici phytochelatin synthase to synthesize gold nanoparticle. We discovered that the reaction mediated by soluble extracts from the recombinant E. coli cells had a higher yield of gold nanoparticles, compared to that from the control cells. The compositional and morphological properties of the gold nanoparticles synthesized by the intracellular extracts from recombinant cells and control cells were similar. In addition, this extracellular nanoparticle synthesis method produced purer gold nanoparticles, avoiding the isolation of nanoparticles from cellular debris when whole cells are used to synthesize nanoparticles. Our results suggested that phytochelatins can improve the efficiency of gold nanoparticle synthesis mediated by bacterial soluble intracellular extracts, and the potential of extracellular nanoparticle synthesis platform for the production of nanoparticles in large quantity and pure form is worth further investigation.

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Huang, Jian-Yuan, Min-Hua Chen, and Feng-Huei Lin. "The Synthesis and Characterization of PEG-SH-Modified Gold Nanoparticle in One-Pot Synthesis by Stenotrophomonas maltophilia." Journal of Nanoscience and Nanotechnology 19, no. 11 (November 1, 2019): 7278–84. http://dx.doi.org/10.1166/jnn.2019.16625.

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Colloidal gold nanoparticles have been researched and utilized in many technical applications. However, the conventionalmethods to produce polyethyleneglycol (PEG) immobilized gold nanoparticles have to take several steps, including residual solvent removing. In the study, we propose an idea green route to synthesize gold nanoparticles by using Stenotrophomonas maltophilia in a one-pot reaction. The relationship between Au precursor and S. maltophilia was evaluated systematically. After PEG-SH addition, the bacterial cell wall was broken down and the synthetic nanoparticles could be released into culture medium. Furthermore, we identified that the crystal structure of synthetic gold nanoparticle was face-center cubic and PEG-SH was immobilized on synthetic gold nanoparticle ideally. The size of Au-PEG-SH was smaller than 30 nm. These findings suggest that gold nanoparticle with PEG-SH modification could be prepared in an eco-friendly one-pot reaction through the metabolic activity of S. maltophilia.

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Compostella, Federica, Olimpia Pitirollo, Alessandro Silvestri, and Laura Polito. "Glyco-gold nanoparticles: synthesis and applications." Beilstein Journal of Organic Chemistry 13 (May 24, 2017): 1008–21. http://dx.doi.org/10.3762/bjoc.13.100.

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Glyco-gold nanoparticles combine in a single entity the peculiar properties of gold nanoparticles with the biological activity of carbohydrates. The result is an exciting nanosystem, able to mimic the natural multivalent presentation of saccharide moieties and to exploit the peculiar optical properties of the metallic core. In this review, we present recent advances on glyco-gold nanoparticle applications in different biological fields, highlighting the key parameters which inspire the glyco nanoparticle design.

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RAJASULOCHANA, P., R. DHAMOTHARAN, P. MURUGAKOOTHAN, S. MURUGESAN, and P. KRISHNAMOORTHY. "BIOSYNTHESIS AND CHARACTERIZATION OF GOLD NANOPARTICLES USING THE ALGA Kappaphycus alvarezii." International Journal of Nanoscience 09, no. 05 (October 2010): 511–16. http://dx.doi.org/10.1142/s0219581x10007149.

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As a part of our ongoing investigation into the use of algae for gold nanoparticle synthesis, we screened the marine alga Kappaphycus alvarezii, to investigate its efficiency to reduce gold ions as well as the formation of gold nanoparticles. In the present work, we report the reaction condition of the alga K. alvarezii with aqueous gold ions for gold nanoparticle synthesis within the biomass extracellularly. The formation of gold nanoparticles was characterized by UV–Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) method. Moreover, we have found that the reaction of gold ions with the K. alvarezii biomass under stationary conditions results in the rapid extracellular formation of gold nanoparticles of spherical morphology. The gold nanoparticles are not toxic to the cells that continued to grow after the biosynthesis of the gold nanoparticles.

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11

Li, Yunbo, Linlin Song, and Yisha Qiao. "Spontaneous assembly and synchronous scan spectra of gold nanoparticle monolayer Janus film with thiol-terminated polystyrene." RSC Adv. 4, no. 101 (2014): 57611–14. http://dx.doi.org/10.1039/c4ra10811f.

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This communication presents a facile method for preparing ordered hydrophilic metal nanoparticles into gold nanoparticle monolayer Janus film. It also reveals the enhanced light source spectrum properties of the gold nanoparticle film.

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Burkitt, Sean, Mana Mehraein, Ramunas K. Stanciauskas, Jos Campbell, Scott Fraser, and Cristina Zavaleta. "Label-Free Visualization and Tracking of Gold Nanoparticles in Vasculature Using Multiphoton Luminescence." Nanomaterials 10, no. 11 (November 12, 2020): 2239. http://dx.doi.org/10.3390/nano10112239.

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Gold nanoparticles continue to generate interest for use in several biomedical applications. Recently, researchers have been focusing on exploiting their dual diagnostic/therapeutic theranostic capabilities. Before clinical translation can occur, regulatory agencies will require a greater understanding of their biodistribution and safety profiles post administration. Previously, the real-time identification and tracking of gold nanoparticles in free-flowing vasculature had not been possible without extrinsic labels such as fluorophores. Here, we present a label-free imaging approach to examine gold nanoparticle (AuNP) activity within the vasculature by utilizing multiphoton intravital microscopy. This method employs a commercially available multiphoton microscopy system to visualize the intrinsic luminescent signal produced by a multiphoton absorption-induced luminescence effect observed in single gold nanoparticles at frame rates necessary for capturing real-time blood flow. This is the first demonstration of visualizing unlabeled gold nanoparticles in an unperturbed vascular environment with frame rates fast enough to achieve particle tracking. Nanoparticle blood concentration curves were also evaluated by the tracking of gold nanoparticle flow in vasculature and verified against known pre-injection concentrations. Half-lives of these gold nanoparticle injections ranged between 67 and 140 s. This label-free imaging approach could provide important structural and functional information in real time to aid in the development and effective analysis of new metallic nanoparticles for various clinical applications in an unperturbed environment, while providing further insight into their complex uptake and clearance pathways.

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13

Stanglmair, Christoph, Frank Neubrech, and Claudia Pacholski. "Chemical Routes to Surface Enhanced Infrared Absorption (SEIRA) Substrates." Zeitschrift für Physikalische Chemie 232, no. 9-11 (August 28, 2018): 1527–39. http://dx.doi.org/10.1515/zpch-2018-1132.

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Abstract Bottom-up strategies for fabricating SEIRA substrates are presented. For this purpose, wet-chemically prepared gold nanoparticles are coated with a polystyrene shell and subsequently self-assembled into different nanostructures such as quasi-hexagonally ordered gold nanoparticle monolayers, double layers, and honeycomb structures. Furthermore elongated gold nanostructures are obtained by sintering of gold nanoparticle double layers. The optical properties of these different gold nanostructures are directly connected to their morphology and geometrical arrangement – leading to surface plasmon resonances from the visible to the infrared wavelength range. Finally, SEIRA enhancement factors are determined. Gold nanoparticle double layers show the best performance as SEIRA substrates.

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& MAHMOOD, HAMID. "THE SYNERGISTIC EFFECT OF GOLD NANOPARTICLE LOADED WITH CEFTAZIDIUM ANTIBIOTIC AGAINST MULTIDRUG ERSISTANCE PSEUDOMONAS AERUGINOSA." IRAQI JOURNAL OF AGRICULTURAL SCIENCES 52, no. 4 (August 22, 2021): 828–35. http://dx.doi.org/10.36103/ijas.v52i4.1391.

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This study was aimed to evaluate the antimicrobial activity of gold nanoparticles that was synthesized by biological method using Aloe Vera extract. The Surface morphology of the synthesized gold nanoparticles was confirmed by Atomic force microscope (AFM) while the nature of functional groups present in gold nanoparticles was determined by FT-IR analysis. The antibacterial activity of gold nanoparticle was tested against multidrug resistance (MDR)pseudomonas aeruginosa, the results showed a significant effect against MDR isolates. Gold nanoparticle was loaded with ceftazidium antibiotic in order to improve the antibacterial activity and drug delivery efficiency. The synergistic effects of biosynthesize gold loaded with ceftazidium antibiotic at different concentration against MDR bacteria were also investigated. The result showed that ceftazidium-loaded nanoparticles have superior effectiveness compared to native ceftazidium against pseudomonas aeruginosa.

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Bozich, Jared S., Samuel E. Lohse, Marco D. Torelli, Catherine J. Murphy, Robert J. Hamers, and Rebecca D. Klaper. "Surface chemistry, charge and ligand type impact the toxicity of gold nanoparticles to Daphnia magna." Environ. Sci.: Nano 1, no. 3 (2014): 260–70. http://dx.doi.org/10.1039/c4en00006d.

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You, Guangning, Shuping Xu, Xingfei Yao, Huanhuan Wu, and Yingying Shi. "Preparation of AuNPs/SF Nanofibers and Its Ability to Inhibit Tumor Growth in Breast Cancer-Bearing Animal Models." Journal of Nanoscience and Nanotechnology 21, no. 2 (February 1, 2021): 921–27. http://dx.doi.org/10.1166/jnn.2021.18640.

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Silk fibroin was used as a stabilizer for gold nanoparticles, and a direct silk fibroin-gold nanoparticle composite system was prepared by a direct compounding method in this paper. The stability of Au NPs/SF in phosphate buffer solution with different pH and KCl concentration was studied. The Au NPs/SF system was characterized by UV-visible light spectrum, transmission electron microscope and infrared spectrum. The silk fibroin-gold nanoparticle composite system was prepared by in situ reduction of chloroauric acid with silk fibroin, according to the change of solution color and the change of ultraviolet absorption peak. The effects of exogenous factors on the stability of the silk fibroin-gold nanoparticle in situ composite system were initially discussed, and its inhibition in breast cancer-bearing animal models was studied. In vivo experiments show that in situ injection of Au NPs/SF nanofibers and treatment with light can effectively control tumor growth. Compared with monodisperse gold nanoparticles, silk fibroin-gold nanoparticles can kill tumor cells and inhibit tumor tissue growth more effectively.

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Rout, Anuradha, Ganjaboy Boltaev, Rashid Ganeev, Yue Fu, Sandeep Maurya, Vyacheslav Kim, Konda Rao, and Chunlei Guo. "Nonlinear Optical Studies of Gold Nanoparticle Films." Nanomaterials 9, no. 2 (February 19, 2019): 291. http://dx.doi.org/10.3390/nano9020291.

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Gold films are widely used for different applications. We present the results of third- and high-order nonlinear optical studies of the thin films fabricated from Au nanoparticle solutions by spin-coating methods. These nanoparticles were synthesized by laser ablation of bulk gold in pure water using 200 ps, 800 nm pulses. The highest values of the nonlinear absorption coefficient (9 × 10−6 cm W−1), nonlinear refractive index (3 × 10−11 cm2 W−1), and saturation intensity (1.3 × 1010 W cm−2) were achieved using 35 fs, 400 nm pulses. We also determined the relaxation time constants for transient absorption (220 fs and 1.6 ps) at 400 nm. The high-order harmonic generation was studied during propagation of 35 fs, 800 nm pulses through the plasma during the ablation of gold nanoparticle film and bulk gold. The highest harmonic cutoff (29th order) was observed in the plasma containing gold nanoparticles.

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Gagliardi, Frank M., Rick D. Franich, and Moshi Geso. "Nanoparticle dose enhancement of synchrotron radiation in PRESAGE dosimeters." Journal of Synchrotron Radiation 27, no. 6 (October 23, 2020): 1590–600. http://dx.doi.org/10.1107/s1600577520012849.

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The physical absorbed dose enhancement by the inclusion of gold and bismuth nanoparticles fabricated into water-equivalent PRESAGE dosimeters was investigated. Nanoparticle-loaded water-equivalent PRESAGE dosimeters were irradiated with superficial, synchrotron and megavoltage X-ray beams. The change in optical density of the dosimeters was measured using UV–Vis spectrophotometry pre- and post-irradiation using a wavelength of 630 nm. Dose enhancement was measured for 5 nm and 50 nm monodispersed gold nanoparticles, 5–50 nm polydispersed bismuth nanoparticles, and 80 nm monodispersed bismuth nanoparticles at concentrations from 0.25 mM to 2 mM. The dose enhancement was highest for the 95.3 keV mean energy synchrotron beam (16–32%) followed by the 150 kVp superficial beam (12–21%) then the 6 MV beam (2–5%). The bismuth nanoparticle-loaded dosimeters produced a larger dose enhancement than the gold nanoparticle-loaded dosimeters in the synchrotron beam for the same concentration. For the superficial and megavoltage beams the dose enhancement was similar for both species of nanoparticles. The dose enhancement increased with nanoparticle concentration in the dosimeters; however, there was no observed nanoparticle size dependence on the dose enhancement.

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Devi, S., B. Singh, A. K. Paul, and S. Tyagi. "Highly sensitive and selective detection of trinitrotoluene using cysteine-capped gold nanoparticles." Analytical Methods 8, no. 22 (2016): 4398–405. http://dx.doi.org/10.1039/c6ay01036a.

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(A) A schematic representation of the formation of cysteine capped gold nanoparticles and their interaction at pH 5 and 9.3. (B) A schematic representation of the formation of a Meisenheimer complex between cysteine modified gold nanoparticles and TNT, and possible cross-linking between gold nanoparticles bound to the Meisenheimer complex with gold nanoparticle bound cysteine.

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Kooij, E. S., M. A. Raza, and H. J. W. Zandvliet. "Innovative gold nanoparticle patterning and selective metallization." MRS Proceedings 1547 (2013): 149–54. http://dx.doi.org/10.1557/opl.2013.684.

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ABSTRACTWe present a simple, novel procedure to selectively deposit gold nanoparticles using pure water. It enables patterning of nanoparticle monolayers with a remarkably high degree of selectivity on flat as well as microstructured oxide surfaces. We demonstrate that water molecules form a thin ‘capping’ layer on exposed thiol molecules within the mercaptan self-assembled layer. This reversible capping of water molecules locally ‘deactivates’ the thiol groups, therewith inhibiting the binding of metallic gold nanoparticles to these specific areas. In addition, we show that this amazing role of water molecules can be used to selectively metalize the patterned gold nanoparticle arrays. Employing an electroless seeded growth process, the isolated seeds are enlarged past the percolation threshold to deposit conducting metal layers.

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SOBHAN, M. A., M. AMS, M. J. WITHFORD, and E. M. GOLDYS. "FORMATION OF COLLOIDAL GOLD NANOPARTICLES BY USING FEMTOSECOND LASER ABLATION." International Journal of Nanoscience 08, no. 01n02 (February 2009): 209–12. http://dx.doi.org/10.1142/s0219581x09005712.

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Colloidal gold nanoparticles were produced by irradiating a gold disc with a femtosecond laser beam in pure deionized water. Variation of laser fluence between 38 and 330 J/cm2 was used to control the nanoparticle size distribution. The nanoparticles produced were spherically shaped with average diameter between 9 and 10 nm. The effect of ablation time on the nanoparticle production efficiency and size distribution was also studied.

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Wang, Shenqing, Xiliang Yan, Gaoxing Su, and Bing Yan. "Cytotoxicity Induction by the Oxidative Reactivity of Nanoparticles Revealed by a Combinatorial GNP Library with Diverse Redox Properties." Molecules 26, no. 12 (June 14, 2021): 3630. http://dx.doi.org/10.3390/molecules26123630.

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It is crucial to establish relationship between nanoparticle structures (or properties) and nanotoxicity. Previous investigations have shown that a nanoparticle’s size, shape, surface and core materials all impact its toxicity. However, the relationship between the redox property of nanoparticles and their toxicity has not been established when all other nanoparticle properties are identical. Here, by synthesizing an 80-membered combinatorial gold nanoparticle (GNP) library with diverse redox properties, we systematically explored this causal relationship. The compelling results revealed that the oxidative reactivity of GNPs, rather than their other physicochemical properties, directly caused cytotoxicity via induction of cellular oxidative stress. Our results show that the redox diversity of nanoparticles is regulated by GNPs modified with redox reactive ligands.

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Romanovskaia, Elena, Peter Slovenský, S. Marzieh Kalantarian, Lila Laundry-Mottiar, Valentin Romanovski, Maroš Halama, Michael Auinger, and Yolanda S. Hedberg. "Electrochemical Estimations of the Gold Nanoparticle Size Effect on Cysteine-Gold Oxidation." Journal of The Electrochemical Society 169, no. 2 (February 1, 2022): 021501. http://dx.doi.org/10.1149/1945-7111/ac4bf8.

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Gold nanoparticles are interesting for nanobiomedical applications, such as for drug delivery and as diagnostic imaging contrast agents. However, their stability and reactivity in-vivo are influenced by their surface properties and size. Here, we investigate the electrochemical oxidation of differently sized citrate-coated gold nanoparticles in the presence and absence of L-cysteine, a thiol-containing amino acid with high binding affinity to gold. We found that smaller sized (5, 10 nm) gold nanoparticles were significantly more susceptible to electrochemical L-cysteine interactions and/or L-cysteine-facilitated gold oxidation than larger (20, 50 nm) sized gold nanoparticles, both for the same mass and nominal surface area, under the conditions investigated (pH 7.4, room temperature, stagnant solutions, and scan rates of 0.5 to 450 mV s−1). The electrochemical measurements of drop-casted gold nanoparticle suspensions on paraffin-impregnated graphite electrodes were susceptible to the quality of the electrode. Increased cycling resulted in irreversible oxidation and detachment/oxidation of gold into solution. Our results suggest that L-cysteine-gold interactions are stronger for smaller nanoparticles.

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Fernandez, Carlos A., and Chien W. Wai. "A Simple and Rapid Method of Making 2D and 3D Arrays of Gold Nanoparticles." Journal of Nanoscience and Nanotechnology 6, no. 3 (March 1, 2006): 669–74. http://dx.doi.org/10.1166/jnn.2006.120.

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Monodispersive gold nanoparticles can be synthesized by a dropwise addition of a reducing agent microemulsion to a gold ion microemulsion followed by immediate stabilization with 1-decanethiol. No size-selective precipitations or digestive ripening procedures are necessary. There is no need for metal functionalization of the surfactant AOT. Gold nanoparticles with an average size of 3.8 nm and a relative size dispersion of 5.4% were observed using n-heptane as a solvent. It seems possible to adjust the nanoparticle size by small changes in the carbon chain length of the solvent. Self-assembled 2D and 3D arrays of gold nanoparticles with adjustable sizes have been obtained on carbon-coated copper grids and on a silicon wafer. The arrays have good crystallinity as evidenced by the external morphology and transmission electron diffraction results. The size of the gold nanoparticle 3D arrays depends on the immersion time and can be greater than 15 μm. This approach could be used to synthesize other noble metal nanoparticle arrays that may lead to new materials for electronic and photonic applications.

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Zhou, Min, Qiu Mei Ma, Yan Wei Wang, and Guang Can Yang. "Gold Nanoparticle Aggregates Preparation by (3-aminpopropyl)- Trimethoxysilane for Highly Active SERS Substrates." Advanced Materials Research 562-564 (August 2012): 94–97. http://dx.doi.org/10.4028/www.scientific.net/amr.562-564.94.

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A simple preparation method of gold nanoparticle aggregates for highly active surface enhanced Raman scattering (SERS) substrates is developed by adding APS to gold sol under vigorous magnetic stirring. The optical and morphological properties of these aggregates are examined by UV-vis spectroscopy and atomic force microscopy. It is found that the SERS activity of the new synthesized gold nanoparticle aggregates is about 200 higher than that of single gold nanoparticles with Rhodamine 6G(R6G) probe.

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Zhou, He, Hongwei Yang, Guangke Wang, Aijun Gao, and Zhiqin Yuan. "Recent Advances of Plasmonic Gold Nanoparticles in Optical Sensing and Therapy." Current Pharmaceutical Design 25, no. 46 (January 10, 2020): 4861–76. http://dx.doi.org/10.2174/1381612826666191219130033.

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: Gold nanoparticles with special surface plasmon resonance have been widely used in sensing and therapy because of their easy preparation, unique optical properties, excellent biocompatibility, etc. The applications of gold nanoparticles in chemo/biosensing, imaging, and therapy reported in 2016-2019, are summarized in this review. Regarding the gold nanoparticle-based sensing or imaging, sensing mechanisms and strategies are provided to illustrate the concepts for designing sensitive and selective detection platforms. Gold nanoparticlemediated therapy is introduced by surface plasmon resonance-based therapy and delivery-based therapy. Beyond the sole therapeutic system, platforms through synergistic therapy are also discussed. In the end, discussion of the challenges and future trends of gold nanoparticle-based sensing and therapy systems is described.

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Manzila, Ifa, Tri Puji Priyatno, and Fikri Hidayatullah. "Konjugat Poliklonal Antibodi Nanopartikel Emas untuk Deteksi Potato Virus Y." Jurnal Fitopatologi Indonesia 16, no. 2 (December 2, 2020): 87–93. http://dx.doi.org/10.14692/jfi.16.2.87-93.

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Polyclonal Antibodi-Gold Nanoparticles for Potato Virus Y Detection Gold nanoparticles are stable colloidal solutions with dimensions of 1-100 nm having surface plasmon resonance with six free electrons. The existing of six free electrons on the surface of a plasmon causes gold nanoparticles to bind easily to various types of bioreseptors including polyclonal antibodies. Polyclonal potato virus Y (PVP) antibodi been successfully conjugate with gold nanoparticles in order to develop a rapid detection for PVY infection in potato plants. The gold nanoparticles was synthetized by the reduction of gold (III) chloride trihydrate (HAuCl4) with 1% sodium citrate. Subsequently, the nanoparticles were used to make gold nanoparticle-antiobody PVY-conjugate. PVY detection was carried out with dot blot method on the nitrocellulose membrane. The results showed that the PVY virus on the membrane can be detected 10-30 minutes after incubation, depend on the concentration of the conjugate and the concentration of the virus in the sampel. The use of gold nanoparticle conjugates can increase the efficiency of the immunodot blot method in about 1 hour, and this method can be developed to be a lateral flow system for field detection of PVY.

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Zambre, Ajit, Nripen Chanda, Sudhirdas Prayaga, Rosana Almudhafar, Raghuraman Kannan, Anandhi Upendran, and Zahra Afrasiabi. "Gold Nanoparticle Based Immunostrip Assay Method for Detection of Protein-A." Applied Mechanics and Materials 229-231 (November 2012): 260–66. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.260.

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We have successfully developed gold nanoparticle based immunostrip assay to detect protein-A (PA). Rabbit polyclonal antibody IGg (αPA) that has affinity to PA was conjugated to gold nanoparticles (GNPs) and the gold nanoconjugate (αPA-GNP) was used to detect protein-A by simple immunostrip assay method. ELISA experiments were used to confirm the retention of binding affinity of antibody towards protein-A after conjugation with gold nanoparticles.

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Clarke, Christian, Deming Liu, Fan Wang, Yongtao Liu, Chaohao Chen, Cuong Ton-That, Xiaoxue Xu, and Dayong Jin. "Large-scale dewetting assembly of gold nanoparticles for plasmonic enhanced upconversion nanoparticles." Nanoscale 10, no. 14 (2018): 6270–76. http://dx.doi.org/10.1039/c7nr08979a.

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Kudryashov, Andrey, Svetlana Baryshnikova, Sergey Gusev, Dmitry Tatarskiy, Ivan Lukichev, Nadezhda Agareva, Andrey Poddel’sky, and Nikita Bityurin. "UV-Induced Gold Nanoparticle Growth in Polystyrene Matrix with Soluble Precursor." Photonics 9, no. 10 (October 19, 2022): 776. http://dx.doi.org/10.3390/photonics9100776.

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It is demonstrated that UV (LED at 365 nm) irradiation with subsequent heating (90–110 °C) of the polystyrene matrix containing a soluble Au(I) compound ((Ph3P)Au(n-Bu)) results in the growth of gold nanoparticles within the sample bulk, as confirmed by UV-vis spectroscopy and TEM electron microscopy. Pure heating of the samples without previous UV irradiation does not provide gold nanoparticles, thereby facilitating optical image printing. Comparing the nanoparticles’ growth kinetics in samples with different precursor content suggests the nanoparticle growth mechanism through Au(I) autocatalytic reduction at the surface of a gold nanoparticle. Within the polymer matrix, this mechanism is suggested for the first time.

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Alnashiri, Hassien M., Fahad M. Aldakheel, Abdulkarim S. Binshaya, Nahed S. Alharthi, and Musthaq Ahmed. "Antimicrobial Analysis of Biosynthesized Lectin-Conjugated Gold Nanoparticles." Adsorption Science & Technology 2022 (March 31, 2022): 1–7. http://dx.doi.org/10.1155/2022/8187260.

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To enhance the bioactivity of molecules through nanoparticles is being tested which has potential use in sustained-release drug delivery systems and to enhance the therapeutic effectiveness of drugs. Our current investigation s is to conjugate lectin to that of a gold nanoparticle (GNP) surface without disturbing the bioactive properties and enhances the antibacterial activity of lectin. Au-lectin nanoparticles were checked for their hemagglutination activity, characterized by transmission electron microscopy (TEM) and UV-visible spectrophotometer. The antibacterial effect of nanoparticle lectin, Au salt nanoparticle, and conjugated Au-lectin was estimated by Kirby-Bauer disc method; MICs were determined by microbroth dilution and compared with ciprofloxacin. These tests were done using known species of bacterial strain of multidrug resistant. The hemagglutination activity of lectin was improved to fourfold after purification. Lectin and Au nanoparticles combined had a significant effect on the inhibition of bacterial growth. No significant differences were observed in the inhibition zone diameters from killed bacteria and its supernatant towards any of the tested organisms. Lectin-conjugated gold particles showed good efficacy as antimicrobial agents and the nanoparticle-killed bacteria to work against the viable population of the same bacterium and/or other bacterial species too.

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Sugata, Emi, and Seiya Kobatake. "Synthesis and optical properties of gold nanoparticle networks cross-linked with chain-length-controlled polymers." RSC Advances 5, no. 44 (2015): 34704–8. http://dx.doi.org/10.1039/c5ra02264a.

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Prasad, B. L. V., C. M. Sorensen, and Kenneth J. Klabunde. "Gold nanoparticle superlattices." Chemical Society Reviews 37, no. 9 (2008): 1871. http://dx.doi.org/10.1039/b712175j.

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Graydon, Oliver. "Gold nanoparticle source." Nature Photonics 10, no. 12 (November 29, 2016): 751. http://dx.doi.org/10.1038/nphoton.2016.243.

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Wang, Zhenxin, and Lina Ma. "Gold nanoparticle probes." Coordination Chemistry Reviews 253, no. 11-12 (June 2009): 1607–18. http://dx.doi.org/10.1016/j.ccr.2009.01.005.

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Lumdee, Chatdanai, Binfeng Yun, and Pieter G. Kik. "Effect of surface roughness on substrate-tuned gold nanoparticle gap plasmon resonances." Nanoscale 7, no. 9 (2015): 4250–55. http://dx.doi.org/10.1039/c4nr05893c.

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The impact of nanoscale surface roughness on substrate-tuned gold nanoparticle plasmon resonances is demonstrated by comparing single-particle scattering spectra with simulated scattering spectra of gold nanoparticles on gold films with realistic roughness.

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Sotiriou, Georgios A., Gion Diego Etterlin, Anastasia Spyrogianni, Frank Krumeich, Jean-Christophe Leroux, and Sotiris E. Pratsinis. "Plasmonic biocompatible silver–gold alloyed nanoparticles." Chem. Commun. 50, no. 88 (2014): 13559–62. http://dx.doi.org/10.1039/c4cc05297h.

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Wang, Fei, Hui Xu, Ying Wei Wang, Jing Yue Fang, Wei Chen, and Xue Ao Zhang. "Self-Assembly of Gold Nanoparticle Arrays with Anodic Aluminum Oxide Template." Advanced Materials Research 1004-1005 (August 2014): 55–58. http://dx.doi.org/10.4028/www.scientific.net/amr.1004-1005.55.

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Nanoparticles and their ordered arrays have many important applications in fields such as electronic, optical, memory storage devices and sensors. Herein, a simple method was used for fabricating three-dimensional ordered gold nanoparticle arrays with template technique. Gold films were deposited onto anodic aluminum oxide by using electron beam evaporation. After thermal annealing, interestingly, order arrays of gold nanoparticles were obtained by a thermodynamically driven self-assembled process. The spectrum taken by UV-Vis spectrophotometer demonstrates clear surface plasmon resonance at around 500 nm, which appears blue-shift compared with usual gold nanoparticles.

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Wu, Nianqiang. "(Invited) Distinguishing Roles of Gold Nanoparticles in Photocatalysis." ECS Meeting Abstracts MA2018-01, no. 31 (April 13, 2018): 1859. http://dx.doi.org/10.1149/ma2018-01/31/1859.

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The addition of gold nanoparticles into the semiconductors has significant effect of on the photocatalysis of the semiconductors. Gold nanoparticles can passivate the semiconductor surface, change the charge dynamics via the Fermi level equilibration, serve as the plasmonic photosensitizers and acts the surface co-catalyst. The gold nanoparticle could play more than two roles simultaneously. This presentation will discuss how to separate each role of the gold nanoparticles.

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Taghavi Moghaddam, Seyed Enayatollah, and Farzin Emami. "Surface-Enhanced Raman Scattering Based on Au-DNA-Ag Plasmonic Nanoparticles." Journal of Nanoelectronics and Optoelectronics 15, no. 11 (November 1, 2020): 1307–11. http://dx.doi.org/10.1166/jno.2020.2855.

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The dependence of the Surface-Enhanced Raman Scattering (SERS) by gold and silver nanoparticles on their shape is examined using the organic dye, as a probe molecule. SERS has been explored extensively for applications in sensing and imaging, but the design and optimization of efficient substrates are still challenging. In order to understand and optimize the SERS process in nanoparticles, gold and silver Nanospheres and their composition as gold-DNA-silver nanoparticle were synthesized and characterized according to their average size, zeta potential and UV/visible absorption. In fact, in this research, an asymmetric new plasmonic nano-particle is proposed and designed as gold-DNA-silver and is compared to gold, silver, gold-DNA-gold, and silver-DNA-silver nanoparticles. With the help of this new nanoparticle, we design and recommend a Raman booster so that the effect of Raman is improved noticeably. It will be shown that using the proposed asymmetric nano-particle of gold-DNA-silver, the absorbance, and intensity of Raman booster is improved noticeably. In suspensions of equal nano-particle and dye concentration, the SERS effect increases as gold- DNA-silver, clearly indicating that control over the number of local field hotspots can optimize the SERS efficiency. Notably, it is demonstrated that the SERS intensity per nanoparticle scales with the magnitude of the SPR absorbance at the excitation wavelength (785 nm), providing a clear guide to optimization of the process experimentally.

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Thaxton, C. Shad, Nathaniel L. Rosi, and Chad A. Mirkin. "Optically and Chemically Encoded Nanoparticle Materials for DNA and Protein Detection." MRS Bulletin 30, no. 5 (May 2005): 376–80. http://dx.doi.org/10.1557/mrs2005.101.

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AbstractNanoscale materials are beginning to have an impact in the field of molecular diagnostics. In particular, gold nanoparticles surface-functionalized with DNA have garnered much recent interest. Due to the unusual optical and catalytic properties of gold nanoparticle labels, several distinct advantages for assay readout have been realized. This review focuses on the progress made in our group over the past seven years in the development of particle surface chemistry and ultrasensitive protein and nucleic acid assays based upon DNA-functionalized gold nanoparticles. For DNA targets, experiments demonstrate that assays based upon gold nanoparticle labels have enhanced target specificity and in certain cases the sensitivity of polymerase chain reaction (PCR), without the need for target amplification. For protein targets, similar experiments demonstrate that assays based upon gold nanoparticles are up to one million times more sensitive than conventional protein detection methods. Recent data using human samples demonstrate the utility of such assays.

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Liu, Guangyang, Meng Lu, Xiaodong Huang, Tengfei Li, and Donghui Xu. "Application of Gold-Nanoparticle Colorimetric Sensing to Rapid Food Safety Screening." Sensors 18, no. 12 (November 27, 2018): 4166. http://dx.doi.org/10.3390/s18124166.

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Due to their unique optical properties, narrow size distributions, and good biological affinity, gold nanoparticles have been widely applied in sensing analysis, catalytic, environmental monitoring, and disease therapy. The color of a gold nanoparticle solution and its maximum characteristic absorption wavelength will change with the particle size and inter-particle spacing. These properties are often used in the detection of hazardous chemicals, such as pesticide residues, heavy metals, banned additives, and biotoxins, in food. Because the gold nanoparticles-colorimetric sensing strategy is simple, quick, and sensitive, this method has extensive applications in real-time on-site monitoring and rapid testing of food quality and safety. Herein, we review the preparation methods, functional modification, photochemical properties, and applications of gold nanoparticle sensors in rapid testing. In addition, we elaborate on the colorimetric sensing mechanisms. Finally, we discuss the advantages and disadvantages of colorimetric sensors based on gold nanoparticles, and directions for future development.

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Devi, J. Meena. "Simulation Studies on the Interaction of Graphene and Gold Nanoparticle." International Journal of Nanoscience 17, no. 03 (May 21, 2018): 1760043. http://dx.doi.org/10.1142/s0219581x17600432.

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In this computational study, the interaction between a single layer graphene sheet and a gold nanoparticle is investigated employing molecular dynamics (MD) simulation at room temperature. The interactions between the graphene and gold nanoparticle were explored for three different types of gold nanoparticle, namely, bare gold nanoparticle, methyl terminated alkane thiol-coated gold nanoparticle and hydroxy terminated alkane thiol-coated gold nanoparticle. The interactions between the graphene and gold nanoparticle have resulted in the adsorption of gold nanoparticle on the surface of graphene. The structural properties of the graphene–gold hybrid nanostructures were found to be influenced by the capping layer of the gold nanoparticle.

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González, V., B. Kharisov, and I. Gómez. "Preparation, optical characterization and stability of gold nanoparticles by facile methods." Revista Mexicana de Física 65, no. 6 Nov-Dec (October 31, 2019): 690. http://dx.doi.org/10.31349/revmexfis.65.690.

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The influence of synthesis method, cycles quantity and sonication time in the gold nanoparticles size and plasmon resonance were analyzed to establish the synthesis with smaller nanoparticle size and higher absorbance. Gold nanoparticles were analyzed by UV-Vis spectrophotometry, dynamic light scattering (DLS) and surface electron microscopy (SEM). The results indicate that the nanoparticles obtained by microwave have bigger size but higher absorption. These nanoparticles were analyzed one year after its synthesis and it was found that the plasmon resonance signal remains almost unchanged. Finally, two equation were derived from the analyzes for estimate molar extinction coefficient, molar concentration and nanoparticle average diameter.

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Harlaftis, Filippos, Dean Kos, Qianqi Lin, Kevin T. P. Lim, Calvin Dumesnil, and Jeremy J. Baumberg. "Trapping plasmonic nanoparticles with MHz electric fields." Applied Physics Letters 120, no. 20 (May 16, 2022): 203303. http://dx.doi.org/10.1063/5.0091763.

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Dielectrophoresis drives the motion of nanoparticles through the interaction of their induced dipoles with a non-uniform electric field. We experimentally observe rf dielectrophoresis on 100 nm diameter gold nanoparticles in a solution and show that for MHz frequencies, the nanoparticles can reversibly aggregate at electrode gaps. A frequency resonance is observed at which reversible trapping of gold nanoparticle “clouds” occurs in the gap center, producing almost a 1000-fold increase in density. Through accounting for gold cores surrounded by a conducting double layer ion shell, a simple model accounts for this reversibility. This suggests that substantial control over nanoparticle separation is possible, enabling the formation of equilibrium nanoarchitectures in specific locations.

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Sheeraz, Zaynah, and James C. L. Chow. "Evaluation of dose enhancement with gold nanoparticles in kilovoltage radiotherapy using the new EGS geometry library in Monte Carlo simulation." AIMS Biophysics 8, no. 4 (2021): 337–45. http://dx.doi.org/10.3934/biophy.2021027.

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<abstract><sec> <title>Purpose</title> This study compared the dose enhancement predicted in kilovoltage gold nanoparticle-enhanced radiotherapy using the newly developed EGS lattice and the typical gold-water mixture method in Monte Carlo simulation. This new method considered the gold nanoparticle-added volume consisting of solid nanoparticles instead of a gold-water mixture. In addition, this particle method is more realistic in simulation. </sec><sec> <title>Methods</title> A heterogeneous phantom containing bone and water was irradiated by the 105 and 220 kVp x-ray beams. Gold nanoparticles were added to the tumour volume with concentration varying from 3–40 mg/mL in the phantom. The dose enhancement ratio (DER), defined as the ratio of dose at the tumour with and without adding gold nanoparticles, was calculated by the gold-water mixture and particle method using Monte Carlo simulation for comparison. </sec><sec> <title>Results</title> It is found that the DER was 1.44–4.71 (105 kVp) and 1.27–2.43 (220 kVp) for the gold nanoparticle concentration range of 3–40 mg/mL, when they were calculated by the gold-water mixture method. The DER was slightly larger and equal to 1.47–4.84 (105 kVp) and 1.29–2.5 (220 kVp) for the same concentration range, when the particle method was used. Moreover, the DER predicted by both methods increased with an increase of nanoparticle concentration, and a decrease of x-ray beam energy. </sec><sec> <title>Conclusion</title> The deviation of DER determined by the particle and gold-water mixture method was insignificant when considering the uncertainty in the calculation of DER (2%) in the nanoparticle concentration range of 3–40 mg/mL. It is therefore concluded that the gold-water mixture method could predict the dose enhancement as accurate as the newly developed particle method. </sec></abstract>

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Sheeraz, Zaynah, and James C. L. Chow. "Evaluation of dose enhancement with gold nanoparticles in kilovoltage radiotherapy using the new EGS geometry library in Monte Carlo simulation." AIMS Biophysics 8, no. 4 (2021): 337–45. http://dx.doi.org/10.3934/biophy.2021027.

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<abstract><sec> <title>Purpose</title> This study compared the dose enhancement predicted in kilovoltage gold nanoparticle-enhanced radiotherapy using the newly developed EGS lattice and the typical gold-water mixture method in Monte Carlo simulation. This new method considered the gold nanoparticle-added volume consisting of solid nanoparticles instead of a gold-water mixture. In addition, this particle method is more realistic in simulation. </sec><sec> <title>Methods</title> A heterogeneous phantom containing bone and water was irradiated by the 105 and 220 kVp x-ray beams. Gold nanoparticles were added to the tumour volume with concentration varying from 3–40 mg/mL in the phantom. The dose enhancement ratio (DER), defined as the ratio of dose at the tumour with and without adding gold nanoparticles, was calculated by the gold-water mixture and particle method using Monte Carlo simulation for comparison. </sec><sec> <title>Results</title> It is found that the DER was 1.44–4.71 (105 kVp) and 1.27–2.43 (220 kVp) for the gold nanoparticle concentration range of 3–40 mg/mL, when they were calculated by the gold-water mixture method. The DER was slightly larger and equal to 1.47–4.84 (105 kVp) and 1.29–2.5 (220 kVp) for the same concentration range, when the particle method was used. Moreover, the DER predicted by both methods increased with an increase of nanoparticle concentration, and a decrease of x-ray beam energy. </sec><sec> <title>Conclusion</title> The deviation of DER determined by the particle and gold-water mixture method was insignificant when considering the uncertainty in the calculation of DER (2%) in the nanoparticle concentration range of 3–40 mg/mL. It is therefore concluded that the gold-water mixture method could predict the dose enhancement as accurate as the newly developed particle method. </sec></abstract>

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Dharanivasan, G., S. U. Mohammed Riyaz, D. Michael Immanuel Jesse, T. Raja Muthuramalingam, G. Rajendran, and K. Kathiravan. "DNA templated self-assembly of gold nanoparticle clusters in the colorimetric detection of plant viral DNA using a gold nanoparticle conjugated bifunctional oligonucleotide probe." RSC Advances 6, no. 14 (2016): 11773–85. http://dx.doi.org/10.1039/c5ra25559g.

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The DNA templated self-assembly of gold nanoparticles clustered in different configurations (nn = 2–∞) was investigated in the colorimetric detection of ToLCNDV DNA using a gold nanoparticle conjugated bifunctional oligonucleotide probe.

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Slepička, Petr, Nikola Slepičková Kasálková, Jakub Siegel, Zdeňka Kolská, and Václav Švorčík. "Methods of Gold and Silver Nanoparticles Preparation." Materials 13, no. 1 (December 18, 2019): 1. http://dx.doi.org/10.3390/ma13010001.

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The versatile family of nanoparticles is considered to have a huge impact on the different fields of materials research, mostly nanoelectronics, catalytic chemistry and in study of cytocompatibility, targeted drug delivery and tissue engineering. Different approaches for nanoparticle preparation have been developed, not only based on “bottom up” and “top down” techniques, but also several procedures of effective nanoparticle modifications have been successfully used. This paper is focused on different techniques of nanoparticles’ preparation, with primary focus on metal nanoparticles. Dispergation methods such as laser ablation and vacuum sputtering are introduced. Condensation methods such as reduction with sodium citrate, the Brust–Schiffrin method and approaches based on ultraviolet light or biosynthesis of silver and gold are also discussed. Basic properties of colloidal solutions are described. Also a historical overview of nanoparticles are briefly introduced together with short introduction to specific properties of nanoparticles and their solutions.

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Thompson, Shelby, Mychele Jorns, and Dimitri Pappas. "Synthesis and Characterization of Dye-Doped Au@SiO₂ Core-Shell Nanoparticles for Super-Resolution Fluorescence Microscopy." Applied Spectroscopy 76, no. 11 (October 24, 2022): 1367–74. http://dx.doi.org/10.1177/00037028221121357.

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Dye-doped nanoparticles have been investigated as bright, fluorescent probes for localization-based super-resolution microscopy. Nanoparticle size is important in super-resolution microscopy to get an accurate size of the object of interest from image analysis. Due to their self-blinking behavior and metal-enhanced fluorescence (MEF), Ag@SiO2 and Au@Ag@SiO2 nanoparticles have shown promise as probes for localization-based super-resolution microscopy. Here, several noble metal-based dye-doped core-shell nanoparticles have been investigated as self-blinking nanomaterial probes. It was observed that both the gold- and silver-plated nanoparticle cores exhibit weak luminescence under certain conditions due to the surface plasmon resonance bands produced by each metal, and the gold cores exhibit blinking behavior which enhances the blinking and fluorescence of the dye-doped nanoparticle. However, the silver-plated nanoparticle cores, while weakly luminescent, did not exhibit any blinking; the dye-doped nanoparticle exhibited the same behavior as the core fluorescent, but did not blink. Because of the blinking behavior, stochastic optical reconstruction microscopy (STORM) super-resolution analysis was able to be performed with performed on the gold core nanoparticles. A preliminary study on the use of these nanoparticles for localization-based super-resolution showed that these nanoparticles are suitable for use in STORM super resolution. Resolution enhancement was two times better than the diffraction limited images, with core sizes reduced to 15 nm using the hybrid Au–Ag cores.

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Journal articles on the topic 'Nanoparticle gold'

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