Concentration Of AuNPs Research Articles

SPR studies in PVA composite films of SiO2@NaYF4:Er3+/Yb3+ UCNPs via AuNPs concentration variation and their temperature sensing applications

The composite film of mesoporous silica coated NaYF4:Er3+/Yb3+ upconversion nanoparticles and gold nanoparticles (AuNPs) in Poly vinyl alcohol (PVA) medium were prepared. The effect of the concentrations of AuNPs with 0 µl, 50 µl, 100 µl and 150 µl on the structure and upconversion luminescence intensity were studied. The phenomenon of enhancement in upconversion luminescence intensity due to AuNPs were explained via surface plasmon resonance (SPR) phenomenon. Apart from this the XRD, FE-SEM and AFM studies were done for estimation of structure and surface morphology etc. The impurities were estimated through FTIR analysis. The optical properties of these polymer composite films were studied via UV–vis absorption spectra and upconversion luminescence spectra analysis. A low temperature sensing ability of these films have been demonstrated for the suitability of these films in bio-medical applications.

Exposure to High Dosage of Gold Nanoparticles Accelerates Growth Rate by Modulating Ribosomal Protein Expression.

Gold nanoparticles (AuNPs) have been utilized in various biomedical applications including diagnostics and drug delivery. However, the cellular and metabolic responses of cells to these particles remain poorly characterized. In this study, we used bacteria (Escherichia coli and Bacillus subtilis) and a fungus (Saccharomyces cerevisiae) as model organisms to investigate the cellular and metabolic effects of exposure to different concentrations of citrate-capped spherical AuNPs with diameters of 5 and 10 nm. In different growth media, the synthesized AuNPs displayed stability and microorganisms exhibited uniform levels of uptake. Exposure to a high concentration of AuNPs (1012 particles) resulted in a reduced cell division time and a 2-fold increase in cell density in both bacteria and fungus. The exposed cells exhibited a decrease in average cell size and an increase in the expression of FtsZ protein (cell division marker), further supporting an accelerated growth rate. Notably, exposure to such a high concentration of AuNPs did not induce DNA damage, envelope stress, or a general stress response in bacteria. Differential whole proteome analysis revealed modulation of ribosomal protein expression upon exposure to AuNPs in both E. coli and S.cerevisiae. Interestingly, the accelerated growth observed upon exposure to AuNPs was sensitive to sub-minimum inhibitory concentration (sub-MIC) concentration of drugs that specifically target ribosome assembly and recycling. Based upon these findings, we hypothesize that exposure to high concentrations of AuNPs induces stress on the translation machinery. This leads to an increase in the protein synthesis rate by modulating ribosome assembly, which results in the rapid proliferation of cells.

Study of biological properties of gold nanoparticles: Low toxicity, no proliferative activity, no ability to induce cell gene expression and no antiviral activity

Gold nanoparticles (AuNPs) are a fundamental building block of many applications across nanotechnology as they have excellent biosafety which make them promising for a broad range of biomedical applications. Here we explore their in vivo toxicity, cytotoxicity and proliferative capacity in human keratinocyte HaCaT cells, their ability to induce gene expression and their antiviral properties against a surrogate of SARS-CoV-2. These nanoparticles were characterized by transmission electron microscopy, dynamic light scattering and zeta potential. The results showed that these AuNPs with sizes ranging from 10 to 60 nm are non-toxic in vivo at any concentration up to 800 μg/mL. However, AuNP cytotoxicity in human HaCaT cells is time-dependent, so that concentrations of up to 300 μg/mL did not show any in vitro toxic effect at 3, 12 and 24 h, although higher concentrations were found to have some significant toxic activity, especially at 24 h. No significant proliferative activity was observed when using low AuNP concentrations (10, 20 and 40 μg/mL), while the AuNP antiviral tests indicated low or insignificant antiviral activity. Surprisingly, none of the 13 analyzed genes had their expressions modified after 24 h's exposure to AuNPs. Therefore, the results show that AuNPs are highly stable inactive materials and thus very promising for biomedical and clinical applications demanding this type of materials.

Self-referencing photothermal digital holographic microscope for characterization of low-loss liquids

Measurement of absorption coefficients of transparent samples is important for their characterization and identification; however, it is challenging to measure low values, e.g., 10−3–10−4 cm−1 with high accuracy. Here, we report a compact photothermal lateral shearing digital holographic device. It is based on the thermal lens effect and a common-path, self-referencing digital holographic microscope comprising a glass plate, probe beam, and a CMOS camera. The change in phase distribution caused by the temperature change due to light absorption is measured from the recorded holograms to extract the sample's absorbance and absorption coefficient. The feasibility of the proposed configuration is validated by the experimental results obtained with different concentrations of gold nanoparticles (AuNPs) in an aqueous solution. Determination of AuNPs concentration in the nM range is performed, and the obtained limits of detection and quantitation are 0.04 nM and 0.13, respectively. The calibration curve is linear at a low concentration range of 0.06–0.95 nM with 1% reproducibility. In addition, the method's versatility is demonstrated by measuring the absorption coefficient of low-loss solvents, such as ethanol and water. The determined absorption coefficients agree with the reported values, confirming that this method provides good spectrometric capabilities, such as high sensitivity and accuracy.

Nanoparticles produced by laser ablation in organic solvent for polylactic acid-based polymer

Recently packing technology has been rising as a new domain for the application of nanoparticles. Herein the synthesis of polylactic acid (PLA) foils decorated with nanoparticles is investigated. The gold nanoparticles (Au NPs) can play a major role in reducing microbial load in aliment and to improve the food packaging quality. Au NPs have been fabricated by laser ablation in an organic liquid and then the PLA, with Au NP composites, has been manufactured through the drop-casting method. The crystalline nature of the produced nanoparticles, of their size and shape have been probed by transmission electron (TEM) and atomic force microscopies (AFM). The concentration of Au NPs has been evaluated by Rutherford Backscattering Spectrometry (RBS). The optical and electrical properties of composites have been tested by UV–ViS spectroscopy. The improvement of the hydrophobicity of the composite surfaces has been analysed by wettability measurements for implementation in the food packaging field.

Rapid and naked-eye colorimetric detection of ultra trace sumatriptan in drinking water, saliva, and human urine samples based on the aggregation of gold nanoparticles

In this study, the determination of sumatriptan (SUM) was performed using a simple, rapid, and precise colorimetric method based on the surface plasmon resonance (SPR) feature of gold nanoparticles (AuNPs). By adding SUM, the aggregation was observed in AuNPs with red-to-blue color shifts. The size distribution of NPs was estimated before and after adding SUM via dynamic light scattering (DLS), which was found to be 15.34 and 97.45 nm, respectively. Characterization of AuNPs, SUM, and AuNPs in combination with SUM was investigated using transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). Examining the effect of pH, the volume of buffer, the concentration of AuNPs, interaction time, and ionic strength revealed that their optimal values were 6, 100 μL, 5 μM, 14 min, and 12 μg L-1, respectively. The suggested method was able to determine the amount of SUM in a linear range of 10 to 250 μg L-1 with a limit of detection (LOD) and limit of quantification (LOQ) of 0.392 and 1.03 μg L-1, respectively. This approach was successfully applied to determine SUM in drinking water, saliva, and human urine samples with relative standard deviations (RSD) lower than 0.03%, 0.3%, and 1.0%, respectively.

Development and Characterization of a AuNP-Genipin-Viscoelastic Collagen Material.

Lower back pain is one of the leading causes of disability, affecting 11.9% of the population worldwide and studies have shown that intervertebral disc degeneration is a common cause for chronic lower back pain. We have explored the combination of three components, viscoelastic collagen, genipin, and gold nanoparticles to determine its potential to promote regeneration of the intervertebral disc, specifically for nucleus pulposus regeneration. The goal of this study was to develop, fabricate and characterize different formulations of viscoelastic collagen conjugated with gold nanoparticles and genipin to assess the feasibility as a tissue template. Results demonstrated the successful attachment of gold nanoparticles to the viscoelastic collagen utilizing the genipin crosslinker. For each of the viscoelastic collagen compositions examined, cell biocompatibility was achieved. The results also demonstrated an increase in stiffness of the material with different sizes and concentrations of AuNPs. Results from the TEM and STEM also demonstrated that the viscoelastic collagen that was developed did not display the characteristic D banding pattern of polymerized collagen. The findings from this study could lead to the development of a more efficient and cost-effective treatment for patients with chronic back pain caused by IVD degeneration.

Photothermal treatment of glioblastoma cells based on plasmonic nanoparticles.

Photothermal therapy based on plasmonic gold nanoparticles is considered a promising approach for cancer treatment. Here, we investigate the in vitro photothermal effect of 30-nm gold nanoparticles, optically excited with a 532-nm continuous laser, on the U87MG malignant glioblastoma cells, and demonstrate the role of nanoparticle concentration and exposure power density in achieving its optimum performance. Laser-induced collective oscillation of electrons in plasmonic gold nanoparticles is employed to generate localized heat to denature tumor cells. Optical spectroscopy is used to measure the plasmonic band of nanoparticles and select the excitation laser light. The MTT assay for the IC50 viability assessment is performed to evaluate the live and metabolically active cells after treatment with plasmonic nanoparticles. The quantitative data is statistically analyzed using analysis of variance followed by Tukey's post hoc test. The viability test demonstrates that the metabolic activity of treated U87MG was decreased compared with untreated cells, leading to the determination of the IC50 as 92 [Formula: see text]. A 532-nm laser light was selected for the excitation of gold nanoparticles since the maximum plasmonic band is at 524 nm. The viability tests show that although cells have natural photothermal agents, their absorption efficiency is very low; therefore, the laser-induced plasmonic effect is necessary to observe photothermal effects. The optimal condition was achieved when the nanoparticle concentration was 92 [Formula: see text], and the exposure power density was 96 [Formula: see text]. Thus, it is demonstrated that plasmonic nanoparticle concentration and laser exposure power density are among the key parameters in the photothermal treatment of cancer cells, and higher concentrations of Au-NPs and laser power density lead to less cell viability in the selected range due to the excitation of gold nanoparticles' localized surface plasmon resonance.

Therapeutic Applications of Mesenchymal Stem Cell Loaded with Gold Nanoparticles for Regenerative Medicine.

In the present study, the various concentrations of AuNP (1.25, 2.5, 5, 10 ppm) were prepared to investigate the biocompatibility, biological performances and cell uptake efficiency via Wharton's jelly mesenchymal stem cells and rat model. The pure AuNP, AuNP combined with Col (AuNP-Col) and FITC conjugated AuNP-Col (AuNP-Col-FITC) were characterized by Ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR) and Dynamic Light Scattering (DLS) assays. For in vitro examinations, we explored whether the Wharton's jelly MSCs had better viability, higher CXCR4 expression, greater migration distance and lower apoptotic-related proteins expression with AuNP 1.25 and 2.5 ppm treatments. Furthermore, we considered whether the treatments of 1.25 and 2.5 ppm AuNP could induce the CXCR4 knocked down Wharton's jelly MSCs to express CXCR4 and reduce the expression level of apoptotic proteins. We also treated the Wharton's jelly MSCs with AuNP-Col to investigate the intracellular uptake mechanisms. The evidence demonstrated the cells uptake AuNP-Col through clathrin-mediated endocytosis and the vacuolar-type H+-ATPase pathway with good stability inside the cells to avoid lysosomal degradation as well as better uptake efficiency. Additionally, the results from in vivo examinations elucidated the 2.5 ppm of AuNP attenuated foreign body responses and had better retention efficacy with tissue integrity in animal model. In conclusion, the evidence demonstrates that AuNP shows promise as a biosafe nanodrug delivery system for development of regenerative medicine coupled with Wharton's jelly MSCs.

High-efficiency plasmonic luminescent solar concentrators based on thiol-ene polymer

Advances in solar energy harvesting technology require innovative approaches to meet the growing energy demand. In this work, we exploit the plasmonic interaction of metal nanoparticles with fluorophores to improve the optical performance of luminescent solar concentrators (LSCs). The plasmonic luminescent solar concentrators (PLSCs) with dimensions of 5 cm × 5 cm × 0.5 cm containing CsPbBr3 quantum dots (QDs) and gold nanoparticles (Au NPs) are fabricated, characterized, and evaluated systematically. As the Au NPs concentration increases, the optical performance of PLSCs exhibits, first enhancement, and then diminishment. When the Au NPs concentration is 2 × 10−4 wt%, the optimal external quantum efficiency, optical conversion efficiency, and power conversion efficiency of the PLSC reach 1.58%, 2.90%, and 0.437%, respectively. At higher concentrations of Au NPs, the non-radiative energy transfer from the CsPbBr3 QDs to the Au NPs leads to a decrease of the emission, which can be confirmed by the decreasing lifetime of the QDs. The overall optical performance of PLSCs depends on two competing effects, excitation rate and non-radiative energy transfer efficiency. Furthermore, the PLSC demonstrate the good aesthetic quality as an excellent substitute for commercial glass. We anticipate that the high optical conversion efficiency of PLSCs based on thiol-ene polymer would shed light on future application in LSCs.

Towards Automated and High-Throughput Quantitative Sizing and Isotopic Analysis of Nanoparticles via Single Particle-ICP-TOF-MS.

The work described herein assesses the ability to characterize gold nanoparticles (Au NPs) of 50 and 100 nm, as well as 60 nm silver shelled gold core nanospheres (Au/Ag NPs), for their mass, respective size, and isotopic composition in an automated and unattended fashion. Here, an innovative autosampler was employed to mix and transport the blanks, standards, and samples into a high-efficiency single particle (SP) introduction system for subsequent analysis by inductively coupled plasma-time of flight-mass spectrometry (ICP-TOF-MS). Optimized NP transport efficiency into the ICP-TOF-MS was determined to be >80%. This combination, SP-ICP-TOF-MS, allowed for high-throughput sample analysis. Specifically, 50 total samples (including blanks/standards) were analyzed over 8 h, to provide an accurate characterization of the NPs. This methodology was implemented over the course of 5 days to assess its long-term reproducibility. Impressively, the in-run and day-to-day variation of sample transport is assessed to be 3.54 and 9.52% relative standard deviation (%RSD), respectively. The determination of Au NP size and concentration was of <5% relative difference from the certified values over these time periods. Isotopic characterization of the 107Ag/109Ag particles (n = 132,630) over the course of the measurements was determined to be 1.0788 ± 0.0030 with high accuracy (0.23% relative difference) when compared to the multi-collector-ICP-MS determination.

One–pot synthesis of gold nanoparticles using Pandanus amaryllifolius leaf extract and their antibacterial, antioxidant, anticancer, and ecotoxicity assessment

This work demonstrated a one–pot synthesis of gold nanoparticles (Au NPs) using Pandanus amaryllifolius leaf extract as well as their biological activity and biocompatibility impacts. The synthesized Au NPs were characterized by UV–vis, FT–IR, XRD, XPS, DLS, ZP, SEM, element mapping, EDX, and TEM analysis. The Au NPs tested against Gram–positive and negative bacteria of Staphylococcus aureus and Escherichia coli. The antioxidant capacity of Au NPs showed a moderate effect. Different concentrations of Au NPs were tested on the MDA–MB–231 epithelial human breast cancer cell line, showing that IC50 value at 118.26 μg/mL. Au NPs treated Artemia salina nauplii did not promote any mortality. By contrast, microphotographic analysis of the Au NPs found in the aggregated form inside the guts region. The 100% Au NPs treated Allium cepa root tip cell showed a mitotic index of 77.63 ± 0.42. This investigation demonstrates that Au NPs have better antioxidant and anticancer activities. In addition, the A. salina nauplii emphasized nontoxicity with biocompatibility. The Au NPs treatments showed a dose–depended response to enhance the mitotic cell divisions of A. cepa root tip cells without chromosomal aberration and no antibacterial efficiency of Au NPs against bacterial pathogens. Our study shows that this one–step synthesis is highly efficient. Near the future, synthesized Au NPs can be used for cancer therapeutic, food packaging, and cosmetic applications.

Pegylated Gold Nanoparticles Conjugated with siRNA: Complexes Formation and Cytotoxicity

Drug delivery systems such as dendrimers, liposomes, polymers or gold/silver nanoparticles could be used to advance modern medicine. One significant pharmacological problem is crossing biological barriers by commonly used drugs, e.g., in the treatment of neurodegenerative diseases, which have a problem of the blood-brain barrier (BBB) restricting drug delivery. Numerous studies have been conducted to find appropriate drug carriers that are safe, biocompatible and efficient. In this work, we evaluate pegylated gold nanoparticles AuNP14a and AuNP14b after their conjugation with therapeutic siRNA directed against APOE4. This genetic risk factor remains the strongest predictor for late-onset Alzheimer's disease. The study aimed to assess the biophysical properties of AuNPs/siAPOE complexes and to check their biological safety on healthy cells using human brain endothelial cells (HBEC-5i). Techniques such as fluorescence polarization, circular dichroism, dynamic light scattering, ζ-potential measurements and gel retardation assay showed that AuNPs form stable complexes with siRNA. Subsequently, cytotoxicity assays proved the biological safety of formed conjugates. Obtained results enabled us to find effective concentrations of AuNPs when complexes are formed and non-toxic for healthy cells. One of the studied nanoparticles, AuNP14b complexed with siRNA, displayed lower cytotoxicity (MTT assay, cells viability -74.8 ± 3.1%) than free nanoparticles (44.7 ± 3.6%). This may be promising for further investigations in nucleic acid delivery and could have practical use in treating neurodegenerative diseases.

Plasmon enhanced photocatalytic degradation of 4-chlorophenol using zinc oxide nanorods decorated with gold nanoparticles as supported catalysts under natural sunlight

The photocatalytic degradation of 4-chlorophenol (4-CP) was evaluated under natural sunlight using zinc oxide nanorods (ZnO NRs) and gold nanoparticles (AuNPs) decorated ZnO NRs catalysts. Microwave-assisted hydrothermal growth of ZnO NRs followed by photoinduced deposition of AuNPs on ZnO NRs was carried out to fabricate the ZnO-Au catalysts. The photocatalytic degradation of 4-CP with different AuNPs sizes and surface coverage obtained from varying Au loading on ZnO NRs was studied. 0.1 mM AuNPs concentration exhibited the best result, with a degradation efficiency of 97% for 10 ppm of 4-CP within 180 min. The degradation enhancement for the ZnO-Au catalysts was owing to enhanced absorption in the visible region. The visible-light-induced localized surface plasmon resonance property of AuNPs reduced the recombination and promoted the electrons and holes separation. The substantial change in the binding energy of the valance band maximum exhibited the charge transfer from AuNPs to ZnO NRs. Photocatalytic degradation of four different concentrations (10, 50, 100, and 200 ppm) of 4-CP was studied. During the photocatalytic degradation, various hydroxylated intermediates formed, namely hydroquinone, benzoquinone, 4-chlorocatechol, and 4-chlororesorcinol. The photocatalytic results indicate that the ZnO-Au catalyst is a promising candidate for environmental decontamination of organic pollutants in the aqueous media.

Gold-nanoparticle-embedded hydrogel droplets with enhanced fluorescence for imaging and quantification of proteins in cells.

Conventional cellular protein detection techniques such as immunocytochemistry and flow cytometry require abundant cells, posing multiple challenges, including difficulty and cost for obtaining enough cells and the potential for clogging the instrument when using flow cytometry. Also, it is challenging to conduct cellular protein imaging and quantification simultaneously from a single experiment. We present a novel 3D platform, which integrates highly biocompatible cell-entrapped alginate hydrogel droplet array with gold-nanoparticle (AuNP)-based metal enhanced fluorescence (MEF), to achieve simultaneous imaging and quantification of proteins in intact cells in a sensitive manner. Compared to 2D immunocytochemistry, this 3D system allows for a higher cell loading capacity per unit area; together with the MEF-based signal enhancement from the embedded AuNPs, sensitive protein quantification was realized. Furthermore, compared to flow cytometry, this platform allows for protein imaging from individual cells. Taking the detection of EpCAM protein in ovarian cancer cells as a model, we optimized the AuNP size and concentration for optimal fluorescent signals. The 5nm AuNPs at 6.54 × 1013 particles/mL proved to be the most effective in signal enhancement, providing 2.4-fold higher signals compared to that without AuNPs and 6.4-fold higher signals than that of 2D immunocytochemistry. The number of cells required in our technology is 1-3 orders of magnitude smaller than that of conventional methods. This AuNP-embedded hydrogel platform combines the benefits of immunocytochemistry and flow cytometry, providing increased assay sensitivity while also allowing for qualitative analysis through imaging, suitable for protein determination in a variety of cells.

A Further Insight into Extraction Procedures Suitable for Separation of Gold Nanoparticles from Environmental Waters

Gold nanoparticles (AuNP) are being utilized in an ever-expanding number of applications ranging from scientific research to industrial processes. Increasing nanoparticle emissions in the environment have become of public and academic concern. Since the effects of AuNP on human health are not fully understood, the accumulation of reliable and detailed data is critical for the assessment of their potential risk of harm to humanity. Even their concentrations in natural and engineered water systems do not belong to commonly published data. To obtain such information, the environmental chemists use various sophisticated analytical methods that are often very expensive. Therefore, this paper aims to challenge the analytical potential and advantages of cheaper and equally reliable alternatives that couple the well-established extraction procedures with common spectrometric methods to quantify the ultratrace concentrations of AuNP in complex aqueous matrices. Both types of extraction procedures, solvent extractions as well as sorbent extractions, are discussed in the text. A detailed inspection of different types of interactions that are responsible for the ability to selectively separate AuNP from mixtures containing various ionic species, gold ions, other metallic nanoparticles, and dissolved organic matter can be found in this overview. The examples of the tolerance limits reported for several coexisting components of interest are also given. Practical applications of the extraction procedures, summarized in this article, were demonstrated in analysis of actual environmental matrices, such as tap, river, lake, brook, mineral, and sea waters.

Laser Ablated Albumin Functionalized Spherical Gold Nanoparticles Indicated for Stem Cell Tracking.

Cell tracking in cell-based therapy applications helps distinguish cell participation among paracrine effect, neovascularization, and matrix deposition. This preliminary study examined the cellular uptake of gold nanoparticles (AuNPs), observing cytotoxicity and uptake of different sizes and AuNPs concentrations in Adipose-derived stromal cells (ASCs). ASCs were incubated for 24 h with Laser ablated Albumin functionalized spherical AuNPs (LA-AuNPs), with average sizes of 2 nm and 53 nm in diameter, in four concentrations, 127 µM, 84 µM, 42 µM, and 23 µM. Cytotoxicity was examined by Live/Dead assay, and erythrocyte hemolysis, and the effect on the cytoskeleton was investigated by immunocytochemistry for β-actin. The LA-AuNPs were internalized by the ASCs in a size and concentration-dependent manner. Clusters were observed as dispersed small ones in the cytosol, and as a sizeable perinuclear cluster, without significant harmful effects on the cells for up to 2 weeks. The Live/Dead and hemolysis percentage results complemented the observations that the larger 53 nm LA-AuNPs in the highest concentrated solution significantly lowered cell viability. The demonstrated safety, cellular uptake, and labelling persistency with LA-AuNPs, synthesized without the combination of chemical solutions, support their use for cell tracking in tissue engineering applications.

Reducing the detection limit of trace metals in water by electrodeposition-assisted laser-induced breakdown spectroscopy with gold nanoparticles

This paper used gold nanoparticles to improve the detection limit of laser-induced breakdown spectroscopy (LIBS) for detecting trace metals in water. Firstly, the Pb and Cr elements in water were enriched to the surface of the Al metal substrate by electrodeposition, the substrate surface with Pb and Cr was dripped with Au NPs solution of different concentrations, then dried, and finally, LIBS analysis was carried out. The results showed that the emissions of Pb (I) and Cr (I) rose and then dropped with the Au NPs concentration, reaching the maximum emission intensity when the concentration of Au nanoparticles was 3.91 ng/mL. Secondly, this paper constructed the standard curves of Pb and Cr in the water, and calculated the limit of detection (LOD), finding that the LOD of Pb and Cr at the Au NPs concentrations of 3.91 ng/mL were lower than those without the Au NPs (0 ng/mL). LOD was reduced to less than half of that without gold nanoparticles. The results showed that, compared with electrodeposited LIBS, nanoparticle-enhanced electrodeposited LIBS could realize the high-sensitivity analysis of heavy metals in the water.

Modifications of the optical and vibrational properties in polylactic acid films by the addition of gold nanoparticles produced by laser ablation in chloroform

Gold nanoparticles (AuNPs) have been produced by laser ablation in chloroform and then embedded in polylactic acid (PLA) thus realizing PLA/Au nanocomposite films. Two initial volumes of chloroform of about 5 and 4 mL have been used, thus obtaining two different PLA/Au nanocomposite films. The effects of the embedded AuNPs into PLA films have been studied using Attenuated Total Reflectance Fourier Transform Infrared (ATR–FTIR) spectroscopy and ultraviolet/visible (UV–Vis) absorption spectroscopy. In the ATR-FTIR spectra, as AuNPs are embedded in PLA and their concentration grows up, the PLA characteristic vibrational features maintain their positions in wavenumber, but their IR absorption increases. This result confirms the presence of AuNPs in PLA and suggests that no strong chemical interaction occurs between PLA and AuNPs and no new bonds are formed. Concerning the UV–Vis optical properties an increase in the PLA optical absorption in the visible region has been also observed when AuNPs are embedded. The AuNPs presence is attested by the appearance of localized surface plasmon resonance (LSPR) absorption peak between 500 and 600 nm that shifts at longer wavelengths and broadens as the AuNPs concentration increases. The PLA absorption edge has been determined and its position in wavelength increases with increasing AuNPs concentrations. This observed absorption edge red shift indicates a decrease in the PLA band gap probably due to the electronic levels introduced by the embedded gold nanoparticles.

The Impact of Gold Nanoparticles Synthesized by Essential Oil of Lemon and Plasma Jet Scheme on Growth Inhibition of Breast Cancer Cells

Gold nanoparticles (AuNPs) have gained significance due to their size and shape. The current study aimed to prepare AuNPs by using green - plasma jet and calculate the cellular toxicity of those manufactured nanomaterials. Aqueous gold tetrachloride salts (HAuCl&lt;sub&gt;4&lt;/sub&gt;&amp;#183;4H&lt;sub&gt;2&lt;/sub&gt;O) and essential oil of lemon peels in different ratios (0:10, 1:9, 2:8, and 3:7) were used to produce AuNPs. The synthesized green-prepared gold was characterized by ultraviolet-visible (UV-vis), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). UV-vis spectrum showed the highest absorption at 540 nm, and the patterns of XRD at the ratio (2:8) showed four peaks occurred at peaks at 2&amp;theta; &amp;#61; 38.1, 44.3, 64.5, and 77.98. FESEM study illustrated that the AuNPs particle sizes range between (38-76 nm). The cell toxicity results have shown the effectiveness of the green synthesized AuNPs on the breast cancer (AMJ13) cell line. The breast cancer (AMJ13) cell line is found to be more inhibited when the concentration of AuNPs reaches 100&amp;#37;. According to the findings, creating nanoparticle materials for the therapy of breast cancer cells using green-cold plasma is a potential technique.