- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Synthesis and Characterization of Thiolate-Protected Gold Nanoparticles of Controlled Diameter
摘要： Gold nanoparticles (AuNPs) have been the focus of many studies owing to their unique optical and electronic properties and versatile applications. However, synthesis of stable and homogeneous AuNPs with a particular choice of size is still a challenge. In this study we describe a direct synthesis approach to produce stable and monodisperse water-soluble AuNPs with a tightly controlled diameter in the 1.7?2.4 nm range. We controlled the size by changing only the sodium hydroxide (NaOH) concentration in the synthesis. Gel electrophoresis, transmission electron microscopy (TEM), and solution X-ray scattering showed that the AuNPs had narrow size-distributions. We further showed that AuNPs of the di?erent sizes were clearly distinguishable in TEM micrographs, paving the way to dual-target labeling. The reactivity of the AuNPs toward DNA and proteins was also demonstrated. We utilized this reactivity to label tail-anchored proteins embedded in the membrane of the anticancer nanodrug Doxil as a means to target it to speci?c cell types. The gold-labeling enabled the precise localization of the tail-anchored proteins in cryo-TEM images of the therapeutic liposomes.
关键词： thiolate-protected,bioconjugation,cryo-TEM,tail-anchored proteins,synthesis,size control,Gold nanoparticles,Doxil
更新于2025-09-16 10:30:52
-
Plasmonic Bubble Nucleation in Binary Liquids
摘要： Metal nanoparticles under laser irradiation can produce enormous heat due to surface plasmon resonance. When submerged in a liquid this can lead to the nucleation of plasmonic bubbles. In the very early stage, the nucleation of a giant vapor bubble was observed with an ultrahigh-speed camera. In this study, the formation of this giant bubble on gold nanoparticles (GNPs) in six binary liquid combinations has been investigated. We find that the time delay between the beginning of the laser heating and the bubble nucleation is determined by the absolute amount of dissolved gas in the liquid. Moreover, the bubble volume mainly depends on the vaporization energy of the liquid, consisting of the latent heat of vaporization and the energy needed to reach the boiling temperature. Our results contribute to controlling the initial giant bubble nucleation and have strong bearings on applications of such bubbles.
关键词： binary liquids,Plasmonic bubbles,dissolved gas,vaporization energy,nucleation,gold nanoparticles
更新于2025-09-16 10:30:52
-
Machine learning based temperature prediction of poly( <i>N</i> -isopropylacrylamide)-capped plasmonic nanoparticle solutions
摘要： The temperature-dependent optical properties of gold nanoparticles that are capped with the thermo-sensitive polymer: ‘poly(N-isopropylacrylamide)’ (PNIPAM), have been studied extensively for several years. Also, their suitability to function as nanoscopic thermometers for bio-sensing applications has been suggested numerous times. In an attempt to establish this, many have studied the temperature-dependent optical resonance characteristics of these particles; however, developing a simple mathematical relationship between the optical measurements and the solution temperature remains an open challenge. In this paper, we attempt to systematically address this problem using machine learning techniques to quickly and accurately predict the solution-temperature, based on spectroscopic data. Our emphasis is on establishing a simple and practically useful solution to this problem. Our dataset comprises spectroscopic absorption data from both nanorods and nanobipyramids capped with PNIPAM, measured at discretely varied and pre-set temperature states. Specific regions of the spectroscopic data are selected as features for prediction using random forest (RF), gradient boosting (GB) and adaptive boosting (AB) regression techniques. Our prediction results indicate that RF and GB techniques can be used successfully to predict solution temperatures instantly to within 1 1C of accuracy.
关键词： PNIPAM,spectroscopic data,temperature prediction,adaptive boosting,machine learning,random forest,gradient boosting,gold nanoparticles
更新于2025-09-16 10:30:52
-
AIP Conference Proceedings [AIP Publishing TECHNOLOGIES AND MATERIALS FOR RENEWABLE ENERGY, ENVIRONMENT AND SUSTAINABILITY: TMREES19Gr - Athens, Greece (4–6 September 2019)] TECHNOLOGIES AND MATERIALS FOR RENEWABLE ENERGY, ENVIRONMENT AND SUSTAINABILITY: TMREES19Gr - Time effect on the red shift of surface plasmonic resonance core-shell SiO2: Gold nanoparticles (AuNPs)
摘要： Spherical gold nanoparticles (AuNPs) chemically synthesized by Turkevich method, it coated with sodium silicate stock solution (Na2SiO3). Study different rate effect (SiO2 and ethanol) on position of surface plasmon resonance (SPR) of gold nanoparticles (AuNPs) after coated by using UV–Vis absorption spectroscopy. UV–vis spectrum showed that rate (SiO2 and ethanol) had effect in the coated gold nanoparticles (AuNPs), that Peak band gold nanoparticles (AuNPs) uncoated at (515nm) and this peak was shifted to longer wavelength (518nm) after coating. Coated after get a little shift in position of surface plasmon resonance (SPR) this means that coated method has an important role in maintain on gold nanoparticles (AuNPs) stability.
关键词： gold nanoparticles (AuNPs),Surface Plasmon Resonance (SPR),Sodium Silicate (Na2SiO3),Turkevich method
更新于2025-09-16 10:30:52
-
Optical Detection of Denatured Ferritin Protein via Plasmonic Gold Nanoparticles Exposure through Aminosilane Solution
摘要： The presence of denatured proteins within a therapeutic drug product can create a series of serious adverse effects, such as mild irritation, immunogenicity, anaphylaxis, or instant death to a patient. The detection of protein degradation is complicated and expensive due to current methods associated with expensive instrumentation, reagents, and processing time. We have demonstrated here a platform for visual biosensing of denatured proteins that is fast, low cost, sensitive, and user friendly by exploiting the plasmonic properties of noble metal nanoparticles. In this study we have exposed artificially heat stressed ferritin and gold nanoparticles to 3-aminopropyl triethoxysilane, which degrades the protein by showing a systematic blue shift in the absorbance spectra of the gold nanoparticle/ferritin and aminosilane solution. This blue shift in absorbance produces a detectable visual color transition from a blue color to a purple hue. By studying the Raman spectroscopy of the gold nanoparticle/ferritin and aminosilane solution, the extent of ferritin degradation was quantified. The degradation of ferritin was again confirmed using dynamic light scattering and was attributed to the aggregation of the ferritin due to accelerated heat stress. We have successfully demonstrated a proof of concept for visually detecting ferritin from horse spleen that has experienced various levels of degradation, including due to heat stress.
关键词： ferritin,gold nanoparticles,biosensor,denatured protein,degraded protein,visual detection
更新于2025-09-16 10:30:52
-
One-Minute Synthesis of Size-Controlled Fucoidan-Gold Nanosystems: Antitumoral Activity and Dark Field Imaging
摘要： Gold nanoparticles (AuNPs) are one of the most studied nanosystems with great potential for biomedical applications, including cancer therapy. Although some gold‐based systems have been described, the use of green and faster methods that allow the control of their properties is of prime importance. Thus, the present study reports a one‐minute microwave‐assisted synthesis of fucoidan‐coated AuNPs with controllable size and high antitumoral activity. The NPs were synthesized using a fucoidan‐enriched fraction extracted from Fucus vesiculosus, as the reducing and capping agent. The ensuing monodispersed and spherical NPs exhibit tiny diameters between 5.8 and 13.4 nm for concentrations of fucoidan between 0.5 and 0.05% (w/v), respectively, as excellent colloidal stability in distinct solutions and culture media. Furthermore, the NPs present antitumoral activity against three human tumor cell lines (MNT‐1, HepG2, and MG‐63), and flow cytometry in combination with dark‐field imaging confirmed the cellular uptake of NPs by MG‐63 cell line.
关键词： gold nanoparticles,microwave irradiation,darkfield imaging,antitumoral activity,fucoidan
更新于2025-09-16 10:30:52
-
Soft-chemistry assisted strong metal-Support interaction on designed plasmonic core-shell photocatalyst for enhanced photocatalytic hydrogen production
摘要： Engineering photocatalysts based on gold nanoparticles (AuNPs) has attracted great attention for the solar energy conversion due to their multiple and unique properties. However, boosting the photocatalytic performance of plasmonic materials for H2 generation have reached some limitation. In this study, we propose a soft-chemistry method for the preparation of strong metal-interaction support (SMSI) to enhance the photocatalytic production of H2. The TiO2 thin overlayer covering finely dispersed AuNPs (forming an SMSI) boost the photocatalytic generation of hydrogen, compared to AuNPs deposited at the surface of TiO2 (labelled as a classical sytem). The pathway of the charge carriers’ dynamics occurred regarding the system configuration are found to be different. The photogenerated electrons are collected by AuNPs in a classical system and act as an active site, while, unconventionally, they are injected back in the titania surface for an SMSI photocatalyst making the system highly efficient. Additionally, the adsorption energy of methanol, theoretically estimated using density functional theory (DFT) methodology, is lower for soft-chemistry SMSI photocatalyst accelerating the kinetics of photocatalytic hydrogen production. SMSI obtained by soft-chemistry is an original concept for highly efficient photocatalytic materials, where the photons-to-energy conversion remains a major challenge.
关键词： hydrogen production,photocatalysts,solar energy conversion,gold nanoparticles,TiO2,SMSI
更新于2025-09-16 10:30:52
-
Gold Nanoparticle-Mediated Generation of Reactive Oxygen Species During Plasmonic Photothermal Therapy: A Comparative Study for Different Particles Size, Shape, and Surface Conjugation
摘要： Gold nanoparticles (AuNPs)-mediated photothermal therapy represents an alternative to the effective ablation of cancer cells. However, the photothermal response of AuNPs must be tailored to improve the therapeutic efficacy of plasmonic photothermal therapy (PPT) and mitigate its side effects. This study presents an alternative to ease the tuning of photothermal efficiency and target selectivity. We use laser-treated spherical and anisotropic AuNPs with different sizes and biocompatible folic acid (FA)-conjugated AuNPs (FA-AuNPs) in the well-known human epithelial cervical cancer (HeLa) cell line. We show that large AuNPs produce a more significant photothermal heating effect than small ones. The thermal response of spherical AuNPs of 9 nm was found to reach a maximum increase of 3.0 ± 1 °C, whereas, with spherical AuNPs of 14 nm, the temperature increased by over 4.4 ± 1 °C. Anisotropic AuNPs of 15 nm reached a maximum of 4.0 ± 1 °C, whereas anisotropic AuNPs of 20 nm reached a significant increase of 5.3 ± 1 °C in the cell culture medium (MEM). Notably, anisotropic AuNPs of 20 nm successfully demonstrates the potential for use as a photothermal agent by showing reduced viability down to 60% at a concentration of 100 μM. Besides, we reveal that high concentrations of reactive oxygen species (ROS) are formed within the irradiated cells. It is likely to give rise in combination with stress by photothermal heating, resulting in significant cell death through acute necrosis by compromising the plasma membrane integrity. Cell death and ROS overproduction during PPT were characterized and quantified using transmission electron microscopy (TEM) and confocal fluorescence microscopy with different fluorescent markers. In addition, we show that FA-AuNPs induce cell death through apoptosis by internal damage, whereas diminishing ROS formation during PPT treatment. Our findings suggest the ability of plasmon-mediated ROS to sensitize cancer cells and make them vulnerable to photothermal damage, as well as the protective role of FA-AuNPs from excessive ROS formation, whereas reducing the risk of undesired side effects due to necrotic death pathway. It allows an improvement in the efficacy of AuNP-based photothermal therapy and a reduction in the number of exposures to high temperatures required to induce thermal stress.
关键词： Reactive oxygen species,Laser irradiation,Gold nanoparticles,Folic acid,Photothermal effect
更新于2025-09-16 10:30:52
-
A Novel Nano-approach for Targeted Inner Ear Imaging
摘要： During the last decade, there have been major improvements in imaging modalities and the development of molecular imaging in general. However detailed inner ear imaging still provides very limited information to physicians. This is unsatisfactory as sensorineural hearing loss is the main cause of permanent hearing loss in adults and at least 134 genetic mutations that result in congenital hearing loss have been identified. We are still unable, in most cases where gross anatomical changes are not observed, to determine the exact cause of hearing loss at a cellular or molecular level in patients using non-invasive techniques. This limitation in inner ear diagnostic modalities is a major obstacle behind the delay in discovering treatments for many of the causes of sensorineural hearing loss. This paper initially investigated the use of targeted gold nanoparticles as contrast agents for inner ear imaging. These nanoparticles have many useful characteristics such as being easy to target and possessing minimal cytotoxicity. We were able to detect the nanoparticles diffusing in the hair cells using confocal microscopy. Regrettably, despite their many admirable characteristics, the gold nanoparticles were unable to significantly enhance CT imaging of the inner ear. Consequently, we investigated liposomal iodine as a potential solution for the unsatisfactory CT contrast obtained with the gold nanoparticles. Fortunately, significant enhancement of the micro-CT image was observed with either Lugol’s solution or liposomal iodine, with Lugol’s solution enabling fine inner ear structures to be detected.
关键词： Targeted contrast agents,Liposomal iodine,Inner ear imaging,Gold nanoparticles
更新于2025-09-16 10:30:52
-
Direct Laser Annealing of Surface‐Enhanced Raman Scattering Substrates
摘要： A laser-annealing technique for the fabrication of surface-enhanced Raman scattering (SERS) substrates consisting of closely packed gold nanoparticles (AuNPs) with high densities and small separation distances is reported. Laser annealing enables strongly localized interaction between the laser spot and the colloidal AuNPs within the irradiation area. Multiple stages of the alternative spin-coating of colloidal AuNPs and laser-annealing processes enable filling of the gaps between the AuNPs by newly produced ones in the subsequent stages. Thus, both the fill factor and the distribution density of the AuNPs are increased largely with increasing the number of fabrication stages, which favors the improvement of the SERS performance. In contrast, the conventional furnace or hot-plate annealing heats the substrate and the colloidal film simultaneously, and the melted AuNPs tend to aggregate to form larger ones with large separation distance. Thus, compared with the SERS effective by furnace-annealed substrates, laser-annealed substrates supply a further enhancement factor larger than 3.7. Thus, laser annealing is proved as a more effective approach for the fabrication of SERS substrates through annealing colloidal AuNPs.
关键词： direct laser annealing,furnace annealing,gap widths,surface-enhanced Raman scattering substrates,fill factors,closely packed gold nanoparticles
更新于2025-09-12 10:27:22