Journal articles: 'RGD nanomaterials'

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Zhao, C. H., X. P. Zhang, and L. Zhang. "RGD peptide functionalized graphene oxide: a bioactive surface for cell-material interactions." Digest Journal of Nanomaterials and Biostructures 17, no. 3 (September 25, 2022): 989–97. http://dx.doi.org/10.15251/djnb.2022.173.989.

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Recently, functionalized graphene-based nanomaterials have gained tremendous attention in biomedical field owing to their biocompatibility, surface functionalizability and their unique mechanical, electronic, and optical properties. Herein, we report a facile one step modification of graphene oxide by RGD peptide, which is known to improve the tissue– material contact by highly specific binding to cellular membrane receptors known as integrins. A detailed structural and morphological characterization of the obtained RGD functionalized graphene oxide (GO-RGD) was performed. The synthesized bioactive composite was used to prepare RGD-GO films by a vacuum filtration method. Additionally, mouse osteoblastic cell (MC3T3-E1) functions including cell attachment, adhesion, proliferation, and differentiation were investigated on GO-RGD films. The results indicated that MC3T3-E1 cell functions were significantly enhanced on GO-RGD films comparing with GO films without functionalization. This study not only demonstrates a facile approach to functionalize graphene oxide with bioactive peptides, but also provides a potential biomaterial for bone repair by improving osteoblastic cell functions.

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Qu, Xiaochao, Xiaoxiao Li, Jingning Liang, Yanran Wang, Muhan Liu, and Jimin Liang. "Micro-CT Imaging of RGD-Conjugated Gold Nanorods Targeting TumorIn Vivo." Journal of Nanomaterials 2016 (2016): 1–13. http://dx.doi.org/10.1155/2016/8368154.

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Gold nanomaterials as computed tomography (CT) contrast agents at lower X-ray dosage to get a higher contrast have advantages of longer imaging time and lower toxic side effects compared to current contrast agents. As a receptor for Cyclo (Arg-Gly-Asp-D-Phe-Lys) (RGD) peptide, integrinαvβ3is overexpressed on some tumor cells and tumor neovasculature. In this paper, we conjugated the RGD peptide on the surface of gold nanorods (AuNRs), designated as RGD-AuNRs, a promising candidate in applications such as tumor targeting and imaging capability for micro-CT imaging. Integrinαvβ3-positive U87 cells and integrinαvβ3-negative HT-29 cells were chosen to establish animal models relatedly and then texted the tumor targeting ability and imaging capability of RGD-AuNRsin vitroandin vivo. The MTT assay and stability measurement showed that RGD-conjugation eliminated their cytotoxicity and improved their biocompatibility and stability. Dark-field imaging of U87 cells and HT-29 cells testified the binding affinities and uptake abilities of RGD-AuNRs, and the results showed that RGD-AuNRs were more specifical to U87 cells. The enhanced micro-CT imaging contrast of intramuscular and subcutaneous injection illustrated the feasibility of RGD-AuNRs to be contrast agents. Furthermore, the micro-CT imaging of targeting U87 and HT-29 tumor models verified the targeting abilities of RGD-AuNRs.

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Li, Jianxia, Leilei Zheng, Lin Zeng, Yan Zhang, Lin Jiang, and Jinlin Song. "RGD Peptide-Grafted Graphene Oxide as a New Biomimetic Nanointerface for Impedance-Monitoring Cell Behaviors." Journal of Nanomaterials 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/2828512.

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A new biomimetic nanointerface was constructed by facile grafting the bioactive arginylglycylaspartic acid (RGD) peptide on the graphene oxide (GO) surface through carbodiimide and N-hydroxysuccinimide coupling amidation reaction. The formed RGD-GO nanocomposites own unique two-dimensional structure and desirable electrochemical performance. The linked RGD peptides could improve GO’s biocompatibility and support the adhesion and proliferation of human periodontal ligament fibroblasts (HPLFs) on RGD-GO biofilm surface. Furthermore the biologically active RGD-GO nanocomposites were demonstrated as a potential biomimetic nanointerface for monitoring cell biobehaviors by electrochemical impedance spectroscopy (EIS). By analysis of the data obtained from equivalent circuit-fitting impedance spectroscopy, the information related to cell membrane capacitance, cell-cell gap resistance, and cell-electrode interface gap resistance in the process of cell adhesion and proliferation could be obtained. Besides, this proposed impedance-based cell sensor could be used to assess the inhibition effect of the lipopolysaccharide (LPS) on the HPLFs proliferation. Findings from this work suggested that RGD peptide functionalized GO nanomaterials may be not only applied in dental tissue engineering but also used as a sensor interface for electrochemical detection and analysis of cell behaviors in vitro.

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Zhang, Ru, Shang Luo, Lin-Kun Hao, Yun-Ying Jiang, Ying Gao, Ning-Ning Zhang, Xue-Cheng Zhang, and Yi-Min Song. "Preparation and Properties of Thrombus-Targeted Urokinase/Multi-Walled Carbon Nanotubes (MWCNTs)-Chitosan (CS)-RGD Drug Delivery System." Journal of Biomedical Nanotechnology 17, no. 9 (September 1, 2021): 1711–25. http://dx.doi.org/10.1166/jbn.2021.3113.

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In order to improve the therapeutic effect, prolong the action time and reduce the side effects of the first generation thrombolytic drug urokinase (UK), a novel UK/multi-walled carbon nanotubes (MWCNTs)-chitosan (CS)-arginine-glycine-aspartic acid (Arg-Gly-Asp) (RGD) drug delivery system was synthesized by chemical bonding/non covalent bond modification/ultrasonic dispersion. The results showed that the diameter of the UK/MWCNTs-CS-RGD drug delivery system was about 30–40 nm, there was a layer of UK was attached to the surface of the tube wall, and the distribution was relatively uniform. The average encapsulation efficiency was 83.10%, and the average drug loading was 12.81%. Interestingly, it also had a certain sustained-release effect, and its release law was best fitted by first-order kinetic equation. Moreover, the accelerated and long-term stability test results show that it had good stability. Compared with free UK, UK/MWCNTs-CS-RGD had thrombolytic effect in vitro. In addition, MTT experiment showed that the prepared MWCNTs-CS-RGD nanomaterials had good biocompatibility. A rabbit model of carotid artery thrombosis was used to conduct targeted thrombolysis experiments in vivo. Compared with free UK, UK/MWCNTs-CS-RGD could be enriched in the thrombosis site to achieve thrombus targeting. UK/MWCNTs-CS-RGD drug delivery system was expected to become an effective thrombolytic drug for targeted therapy of thrombosis.

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Wu, Xiaoxia, Yan Peng, Xiaomei Duan, Lingyan Yang, Jinze Lan, and Fu Wang. "Homologous Gold Nanoparticles and Nanoclusters Composites with Enhanced Surface Raman Scattering and Metal Fluorescence for Cancer Imaging." Nanomaterials 8, no. 10 (October 11, 2018): 819. http://dx.doi.org/10.3390/nano8100819.

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A large number of deaths from cancer can be attributed to the lack of effective early-stage diagnostic techniques. Thus, accurate and effective early diagnosis is a major research goal worldwide. With the unique phenomenon of localized surface plasmon resonance (LSPR), plasmonic nanomaterials have attracted considerable attention for applications in surface-enhanced Raman scattering (SERS) and metal-enhanced fluorescence (MEF). Both SERS and MEF are ultra-sensitive methods for the detection and identification of early tumor at molecular level. To combine the merits of the fast and accurate imaging of MEF and the stable and clear imaging of SERS, we propose a novel dual functional imaging nanoprobe based on gold nanoparticles and gold nanocluster composites (denoted AuNPC-RGD). The gold nanoparticles are used as LSPR substrates to realized enhancement of Raman or fluorescence signal, while the gold nanoclusters serve as a fluorophore for MEF imaging, and exhibit better biocompatibility and stability. Furthermore, target molecule of cyclic Arg-Gly-Asp (cRGD) is incorporated into the composite to improve delivery efficiency, selectivity and imaging accuracy. These integrated properties endow AuNPC-RGD composites with outstanding biocompatibility and excellent imaging abilities, which could be used to achieve accurate and effective diagnosis for early cancer.

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Yin, Bohan, Hongrong Yang, and Mo Yang. "Integrating Soft Hydrogel with Nanostructures Reinforces Stem Cell Adhesion and Differentiation." Journal of Composites Science 6, no. 1 (January 6, 2022): 19. http://dx.doi.org/10.3390/jcs6010019.

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Biophysical cues can regulate stem cell behaviours and have been considered as critical parameters of synthetic biomaterials for tissue engineering. In particular, hydrogels have been utilized as promising biomimetic and biocompatible materials to emulate the microenvironment. Therefore, well-defined mechanical properties of a hydrogel are important to direct desirable phenotypes of cells. Yet, limited research pays attention to engineering soft hydrogel with improved cell adhesive property, which is crucial for stem cell differentiation. Herein, we introduce silica nanoparticles (SiO2 NPs) onto the surface of methacrylated hyaluronic (MeHA) hydrogel to manipulate the presentation of cell adhesive ligands (RGD) clusters, while remaining similar bulk mechanical properties (2.79 ± 0.31 kPa) to that of MeHA hydrogel (3.08 ± 0.68 kPa). RGD peptides are either randomly decorated in the MeHA hydrogel network or on the immobilized SiO2 NPs (forming MeHA–SiO2). Our results showed that human mesenchymal stem cells exhibited a ~1.3-fold increase in the percentage of initial cell attachment, a ~2-fold increase in cell spreading area, and enhanced expressions of early-stage osteogenic markers (RUNX2 and alkaline phosphatase) for cells undergoing osteogenic differentiation with the osteogenic medium on MeHA–SiO2 hydrogel, compared to those cultured on MeHA hydrogel. Importantly, the cells cultivated on MeHA–SiO2 expressed a ~5-fold increase in nuclear localization ratio of the yes-associated protein, which is known to be mechanosensory in stem cells, compared to the cells cultured on MeHA hydrogel, thereby promoting osteogenic differentiation of stem cells. These findings demonstrate the potential use of nanomaterials into a soft polymeric matrix for enhanced cell adhesion and provide valuable guidance for the rational design of biomaterials for implantation.

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Afami, Marina E., Ikhlas El Karim, Imad About, Anna D. Krasnodembskaya, Garry Laverty, and Fionnuala T. Lundy. "Multicomponent Peptide Hydrogels as an Innovative Platform for Cell-Based Tissue Engineering in the Dental Pulp." Pharmaceutics 13, no. 10 (September 28, 2021): 1575. http://dx.doi.org/10.3390/pharmaceutics13101575.

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In light of the increasing levels of antibiotic resistance, nanomaterials and novel biologics are urgently required to manage bacterial infections. To date, commercially available self-assembling peptide hydrogels have not been studied extensively for their ability to inhibit micro-organisms relevant to tissue engineering sites such as dental root canals. In this work, we assess the biocompatibility of dental pulp stem/stromal cells with commercially available multicomponent peptide hydrogels. We also determine the effects of dental pulp stem/stromal cell (DPSC) culture in hydrogels on growth factor/cytokine expression. Furthermore, to investigate novel aspects of self-assembling peptide hydrogels, we determine their antimicrobial activity against the oral pathogens Staphylococcus aureus, Enterococcus faecalis, and Fusobacterium nucleatum. We show that self-assembling peptide hydrogels and hydrogels functionalized with the adhesion motif Arg-Gly-Asp (RGD) are biocompatible with DPSCs, and that cells grown in 3D hydrogel cultures produce a discrete secretome compared with 2D-cultured cells. Furthermore, we show that soluble peptides and assembled hydrogels have antimicrobial effects against oral pathogens. Given their antibacterial activity against oral pathogens, biocompatibility with dental pulp stem/stromal cells and enhancement of an angiogenic secretome, multicomponent peptide hydrogels hold promise for translational use.

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Camacho, Ángela, Álvaro Duarte, Darwin Dubay, Enrique Forero, Edgar González, Franklin Jaramillo, Carlos Maldonado, et al. "Definición de nanomateriales para Colombia." Revista Colombiana de Química 45, no. 1 (August 11, 2016): 15. http://dx.doi.org/10.15446/rev.colomb.quim.v45n1.58955.

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Debido a la creciente producción y uso de nanomateriales para actividades de investigación y desarrollo en Colombia, es necesario establecer una definición del término nanomaterial que facilite la toma de decisiones en torno a iniciativas de carácter regulatorio y de normatividad. Se presenta la definición de nanomateriales para Colombia que ha adoptado el Consejo Nacional Asesor de Nanociencia y Nanotecnología adscrito a la Red Colombiana de Nanociencia y Nanotecnología.

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Yedgar, Saul, Gregory Barshtein, and Alexander Gural. "Hemolytic Activity of Nanoparticles as a Marker of Their Hemocompatibility." Micromachines 13, no. 12 (November 27, 2022): 2091. http://dx.doi.org/10.3390/mi13122091.

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The potential use of nanomaterials in medicine offers opportunities for novel therapeutic approaches to treating complex disorders. For that reason, a new branch of science, named nanotoxicology, which aims to study the dangerous effects of nanomaterials on human health and on the environment, has recently emerged. However, the toxicity and risk associated with nanomaterials are unclear or not completely understood. The development of an adequate experimental strategy for assessing the toxicity of nanomaterials may include a rapid/express method that will reliably, quickly, and cheaply make an initial assessment. One possibility is the characterization of the hemocompatibility of nanomaterials, which includes their hemolytic activity as a marker. In this review, we consider various factors affecting the hemolytic activity of nanomaterials and draw the reader’s attention to the fact that the formation of a protein corona around a nanoparticle can significantly change its interaction with the red cell. This leads us to suggest that the nanomaterial hemolytic activity in the buffer does not reflect the situation in the blood plasma. As a recommendation, we propose studying the hemocompatibility of nanomaterials under more physiologically relevant conditions, in the presence of plasma proteins in the medium and under mechanical stress.

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Akpe, Victor, Tak H. Kim, Christopher L. Brown, and Ian E. Cock. "Circulating tumour cells: a broad perspective." Journal of The Royal Society Interface 17, no. 168 (July 2020): 20200065. http://dx.doi.org/10.1098/rsif.2020.0065.

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Circulating tumour cells (CTCs) have recently been identified as valuable biomarkers for diagnostic and prognostic evaluations, as well for monitoring therapeutic responses to treatments. CTCs are rare cells which may be present as one CTC surrounded by approximately 1 million white blood cells and 1 billion red blood cells per millilitre of peripheral blood. Despite the various challenges in CTC detection, considerable progress in detection methods have been documented in recent times, particularly for methodologies incorporating nanomaterial-based platforms and/or integrated microfluidics. Herein, we summarize the importance of CTCs as biological markers for tumour detection, highlight their mechanism of cellular invasion and discuss the various challenges associated with CTC research, including vulnerability, heterogeneity, phenotypicity and size differences. In addition, we describe nanomaterial agents used for electrochemistry and surface plasmon resonance applications, which have recently been used to selectively capture cancer cells and amplify signals for CTC detection. The intrinsic properties of nanomaterials have also recently been exploited to achieve photothermal destruction of cancer cells. This review describes recent advancements and future perspectives in the CTC field.

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Rajaramanan, Tharmakularasa, Muthukumarasamy Natarajan, Punniamoorthy Ravirajan, Meena Senthilnanthanan, and Dhayalan Velauthapillai. "Ruthenium (Ru) Doped Titanium Dioxide (P25) Electrode for Dye Sensitized Solar Cells." Energies 13, no. 7 (March 25, 2020): 1532. http://dx.doi.org/10.3390/en13071532.

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In this study, P25-titanium dioxide (TiO2) was doped with ruthenium (Ru) by systematically varying the Ru content at 0.15, 0.30, 0.45 and 0.6 mol%. The synthesized Ru-doped TiO2 nanomaterials have been characterized by X-ray diffraction (XRD), Raman spectroscopy, energy-dispersive X-ray (EDX) analysis, UV-visible (UV–Vis) spectroscopy, and electrochemical impedance (EIS) spectroscopy. The XRD patterns of undoped and Ru-doped TiO2 nanomaterials confirm the presence of mixed anatase and rutile phases of TiO2 while EDX spectrum confirms the presence of Ti, O and Ru. Further, UV-visible absorption spectra of doped TiO2 nanomaterial reveal a slight red shift on Ru-doping. The short circuit current density (JSC) of the cells fabricated using the Ru-doped TiO2 photoanode was found to be dependent on the amount of Ru present in TiO2. Optimized cells with 0.3 mol% Ru-doped TiO2 electrodes showed efficiency which is 20% more than the efficiency of the control cell (η = 5.8%) under stimulated illumination (100 mWcm−2, 1 sun) with AM 1.5 filter. The increase in JSC resulted from the reduced rate of recombination upon doping of Ru and this was confirmed by EIS analysis.

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Kamenska, Trayana, Miroslav Abrashev, Milena Georgieva, and Natalia Krasteva. "Impact of Polyethylene Glycol Functionalization of Graphene Oxide on Anticoagulation and Haemolytic Properties of Human Blood." Materials 14, no. 17 (August 26, 2021): 4853. http://dx.doi.org/10.3390/ma14174853.

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Graphene oxide (GO) is one of the most explored nanomaterials in recent years. It has numerous biomedical applications as a nanomaterial including drug and gene delivery, contrast imaging, cancer treatment, etc. Since most of these applications need intravenous administration of graphene oxide and derivatives, the evaluation of their haemocompatibility is an essential preliminary step for any of the developed GO applications. Plentiful data show that functionalization of graphene oxide nanoparticles with polyethylene glycol (PEG) increases biocompatibility, thus allowing PEGylated GO to elicit less dramatic blood cell responses than their pristine counterparts. Therefore, in this work, we PEGylated graphene oxide nanoparticles and evaluated the effects of their PEGylation on the structure and function of human blood components, especially on the morphology and the haemolytic potential of red blood cells (RBCs). Further, we studied the effect of PEGylation on some blood coagulation factors, including plasma fibrinogen as well as on the activated partial thromboplastin (aPTT), prothrombin time (PT) and platelet aggregation. Our findings provide important information on the mechanisms through which PEGylation increases GO compatibility with human blood cells. These data are crucial for the molecular design and biomedical applications of PEGylated graphene oxide nanomaterials in the future.

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Kunwar, Srijal, Arpita Roy, Utsav Bhusal, Amel Gacem, Mahmood M. S. Abdullah, Promila Sharma, Krishna Kumar Yadav, et al. "Bio-Fabrication of Cu/Ag/Zn Nanoparticles and Their Antioxidant and Dye Degradation Activities." Catalysts 13, no. 5 (May 15, 2023): 891. http://dx.doi.org/10.3390/catal13050891.

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The biological synthesis of nanoparticles with copper, silver, and zinc (Cu, Ag, Zn) is reported in this study, adopting a greener, safe, reliable, and eco-friendly approach by using an aqueous leaf extract of Catharanthus roseus. The synthesised trimetallic nanoparticles were characterised using different characterisation techniques. The UV–visible spectroscopic technique was initially used to assess nanoparticle formation, in which absorption bands were observed at 220, 270, and 370 nm for Cu, Zn, and Ag nanocomposites, respectively. XRD revealed that the average crystalline size of the nanocomposites was 34.67 nm. The roles of reducing and capping/stabilising agents in the synthesis of Cu/Ag/Zn nanoparticles were confirmed by FTIR analysis, and the successful biosynthesis of the same was also confirmed by X-ray energy-dispersive spectroscopy (EDX) analysis. Potential applications of these synthesised trimetallic nanoparticles were evaluated by assessing their antioxidant and catalytic dye degradation activities. The antioxidant activity of the synthesised nanomaterial was studied using the DPPH assay. The catalytic breakdown of the harmful dyes phenol red and eosin yellow was examined using NaBH4 as a reducing agent. The results showed that the nanomaterial’s radical scavenging capacity at 1000 ug/mL was 75.76% and the degradation of these dyes was up to 78% in the presence of NaBH4. Furthermore, the biogenic trimetallic nanomaterial exhibited effective catalytic degradation activity against methyl red and phenol red dyes.

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Kalhori, Hamid, Raheb Bagherpour, Mohammad Amir Akhlaghi, Sayed Mohsen Mirdamadi, and Mehdi Nasiri Sarvi. "LABORATORY TESTS ON THE STRENGTHENING OF WET-MIX SHOTCRETE LINING WITH THE USE OF NANOMATERIALS." Rudarsko-geološko-naftni zbornik 36, no. 1 (2021): 49–59. http://dx.doi.org/10.17794/rgn.2021.1.5.

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Adding nanomaterials to concrete extends the size range of constituent particles well into nano-scale dimensions, which could help the compacting of particles in cement-based materials. Regarding the differences between shotcrete and cast concrete, in this study, the properties of shotcrete with nano and micro-silica and nano-clay were experimentally studied. The micro and nanomaterials have been added at different percentages (6%, 9%, and 12%) to a shotcrete paste. The comparison was based on the uniaxial compressive strength, flexural strength, tensile strength, and porosity tests of different specimens. The results indicated that the maximum increase in compressive, flexural, and tensile strengths of shotcrete was related to 12% nano-SiO2, while for 12% nano-clay, all of these strengths were decreased at 28 days. The optimum percentage for shotcrete substitution by nano-clay was established to be 6%. Also, the application of the nanomaterials led to a decrease in the water absorption and porosity of shotcrete. Eventually, the results revealed that the improvement of mechanical properties by the introduction of the nanomaterials in shotcrete could be satisfactory.

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Singh, Amanvir, Surjeet Chahal, Heena Dahiya, Arkaja Goswami, and Sonia Nain. "Synthesis of Ag nanoparticle supported graphene/multi-walled carbon nanotube based nanohybrids for photodegradation of toxic dyes." Materials Express 11, no. 6 (June 1, 2021): 936–46. http://dx.doi.org/10.1166/mex.2021.1972.

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Irrespective of the superior surface properties of graphene, research interests are impulsively devoted to synthesizing 1-D carbon nanomaterial-based binary or ternary nanocomposites for potential applications. Nevertheless, an insightful comparison between the properties of graphene oxide (GO) and carbon nanotubes (CNTs) is lacking in the literature. In the present work, quasi-spherical silver nanoparticles (Ag NPs) were anchored on two different carbon nanomaterial/Ag-based photocatalysts, GO/Ag and multiwalled CNT (MWCNT)/Ag via a modified one-pot synthesis approach. The synthesized Ag NPs and photocatalysts were analyzed using XRD, FTIR, FESEM, TEM, and UV-Vis spectroscopy and tested for their photocatalytic efficiency against three different toxic organic dyes, namely rose bengal (RB), methylene blue (MB), and phenol red (PR). During the photocatalytic process, the reactive oxygen species generated via interband transitions from the surface plasmonic resonance of Ag NPs acted synergistically with unique electrostatic interactions by carbon nanomaterials in the GO/Ag-based catalyst to degrade RB, MB, and PR dyes by 92, 87.6, and 81.4%, respectively within 120 min of UV irradiation. Furthermore, temperature dependence and electricity cost consumption were evaluated to establish the specific advantages of GO over its carbon-based counterparts for the purification of wastewater.

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Turcu, Elvira, Cristina Giorgiana Coromelci, Valeria Harabagiu, and Maria Ignat. "Enhancing the Photocatalytic Activity of TiO2 for the Degradation of Congo Red Dye by Adjusting the Ultrasonication Regime Applied in Its Synthesis Procedure." Catalysts 13, no. 2 (February 3, 2023): 345. http://dx.doi.org/10.3390/catal13020345.

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Recently, the ultrasound-assisted sol-gel synthesis procedure of mesoporous titania (TiO2) photocatalysts caught the researcher’s attention, due to the physicochemical properties enhancement of the resulting titania nanomaterials. Thus, by varying different synthesis parameters particular characteristics could be obtained. In the present study, the ultrasound pulse on/off ratio has been considered and the effect of the envisaged parameter on the textural, morphological, and optical features of titania nanomaterial has been investigated. Therefore, X-ray Diffraction (XRD), Fourier-Transform Infrared spectroscopy (FTIR), N2-sorption measurements, SEM imaging, and UV-Vis Diffuse Reflectance spectroscopy (UVDR) have been used. And further, the photocatalytic activity of the prepared TiO2 materials was evaluated by the features developed about the applied ultrasound pulse on/off ratio as 1/1, 2/1, 3/1, 4/1, 1/3 and 2/2. It was found that the ultrasound pulse on/off ratio considered in the synthesis procedure of titania leads to TiO2 materials with different textural (SBET = 98–156 m2/g), morphological, and optical (Eg = 3.1–3.2 eV) characteristics. For this reason, TiO2 nanomaterials prepared were found to exhibit suitable features for photocatalytic applications. Thus, the TiO2 4.1 sample prepared at 4/1 ultrasound pulse on/off ratio revealed the highest photodegradation efficiency of Congo Red dye (98.28%) as the results of photocatalytic tests show. More than that, a possible reaction mechanism of the CR photodegradation process through the contribution of reactive oxygen species (·HO, ·O2−), holes (h+), and electrons (e−) of developed titania photocatalyst was proposed.

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Alamier, Waleed M., Nazim Hasan, Syed Kashif Ali, and Mohammed D. Y. Oteef. "Biosynthesis of Ag Nanoparticles Using Caralluma acutangula Extract and Its Catalytic Functionality towards Degradation of Hazardous Dye Pollutants." Crystals 12, no. 8 (July 30, 2022): 1069. http://dx.doi.org/10.3390/cryst12081069.

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Nanomaterials, today, are an integral part of our everyday lives, industrial processes and appliances. Biosynthesis, because of its environmental sustainability, is now becoming a hot topic. The biosynthesis of nanomaterials using plant phytochemicals enhances the nanomaterial’s biocompatibility and its compatibility with the environment too. Hence, forthe first time, this study uses Caralluma acutangula (CA) plant extracts to synthesize silver nanoparticles (CA-AgNPs) and characterize them using UV–visible spectroscopy, FTIR, Raman spectroscopy, XRD, TEM, TGA, SEM, EDX, zeta potential, and bandgap analysis. The particle size distributions of CA-AgNPs were observed to fall in the range of 2–6 nm predominantly using TEM images. High crystallinity % was calculated as 86.01 using XRD data. Extracted phytochemicals from CA were characterized and analyzed using GC-MS. The bandgap (Eg) of CA-AgNPs was calculated as 3.01 eV and zeta potential was found to be −16.1 mV. The biosynthesized CA-AgNPs were confirmed for their degradation efficiency of two toxic water pollutant dyes: Congo red, CR (95.24% degradation within 36 min), and methylene blue, MB (96.72% degradation within 32 min), in the presence of NaBH4. Different doses of CA-AgNPs and NaBH4 were checked for their chemical kinetics and rate constant analysis. The chemical kinetics were explored on the basis of integrated rate law model equations and confirmed as pseudo-zero-order reactionsfor CR and MB dyes. The rate constant ‘k’ for CR and MB was calculated as 0.0311 and 0.0431 mol.L−1.min−1, respectively.

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Bou Orm, Nadine, Quoc Trieu, and Stephane Daniele. "TiO2-Based Hybrid Nanocomposites Modified by Phosphonate Molecules as Selective PAH Adsorbents." Molecules 23, no. 11 (November 21, 2018): 3046. http://dx.doi.org/10.3390/molecules23113046.

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A robust sol-gel process was developed for the synthesis of surface-functionalized titania nanocrystallites bearing unsaturated groups starting from molecular heteroleptic single-source precursors. Molecules and nanomaterials were thoroughly characterized by multinuclear liquid and solid-state nuclear magnetic resonance (NMR), infra-red (FT-IR, DRIFT) spectroscopies. Nitrogen adsorption-desorption (BET), thermogravimetric (TG) and elemental analyses demonstrated the reliability and the fine tuning of the surface functionalization in terms of ratio TiO2:ligand. The as-prepared materials were used as nano-adsorbents to remove mixture of 16 polycyclic aromatic hydrocarbon (PAHs) from aqueous solutions. Adsorption kinetic experiments were carried out for 24 h in solutions of one PAH [benzo(a)pyrene, 220 ppb] and of a mixture of sixteen ones [220 ppb for each PAH]. Most kinetic data best fitted the pseudo-second order model. However, in PAHs mixture, a competition process took place during the first hours leading to a remarkable high selectivity between light and heavy PAHs. This selectivity could be fine-tuned depending on the nature of the unsaturated group of the phosphonate framework and on the nanomaterial textures.

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Ahsan, Hajra, Muhammad Shahid, Muhammad Imran, Faisal Mahmood, Muhammad Hussnain Siddique, Hayssam M. Ali, Muhammad B. K. Niazi, et al. "Photocatalysis and adsorption kinetics of azo dyes by nanoparticles of nickel oxide and copper oxide and their nanocomposite in an aqueous medium." PeerJ 10 (November 14, 2022): e14358. http://dx.doi.org/10.7717/peerj.14358.

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Background Azo dyes are recalcitrant organic pollutants present in textile industry effluents. Conventional treatment methods to remove them come with a range of disadvantages. Nanoparticles and their nanocomposites offer more efficient, less expensive and easy to handle wastewater treatment alternative. Methods In this study, nanoparticles of nickel oxide (NiO-NPs), copper oxide (CuO-NPs) and their nanocomposite (NiO/CuO-NC) were synthesized using co-precipitation method. The functional groups present on the surface of synthesized nanomaterials were verified using Fourier-transform infrared spectroscopy (FTIR). Surface morphology was assessed using scanning electron microscopy (SEM) whereas purity, shape and size of the crystallite were determined using X-ray diffraction (XRD) technique. The potential of these nanomaterials to degrade three dyes i.e., Reactive Red-2 (RR-2), Reactive Black-5 (RB-5) and Orange II sodium salt (OII) azo dyes, was determined in an aqueous medium under visible light (photocatalysis). The photodegradation effectiveness of all nanomaterials was evaluated under different factors like nanomaterial dose (0.02–0.1 g 10 mL−1), concentration of dyes (20–100 mg L−1), and irradiation time (60–120 min). They were also assessed for their potential to adsorb RR-2 and OII dyes. Results Results revealed that at optimum concentration (60 mgL−1) of RR-2, RB-5, and OII dyes, NiO-NPs degraded 90, 82 and 83%, CuO-NPs degraded 49, 34, and 44%, whereas the nanocomposite NiO/CuO-NC degraded 92, 93, and 96% of the said dyes respectively. The nanomaterials were categorized as the efficient degraders of the dyes in the order: NiO/CuO-NC > NiO-NPs > CuO-NPs. The highest degradation potential shown by the nanocomposite was attributed to its large surface area, small particles size, and quick reactions which were proved by advance analytical techniques. The equilibrium and kinetic adsorption of RR-2 and OII on NiO-NPs, CuO-NPs, and NiO/CuO-NC were well explained with Langmuir and Pseudo second order model, respectively (R2 ≥ 0.96). The maximum RR-2 adsorption (103 mg/g) was obtained with NiO/CuO-NC. It is concluded that nanocomposites are more efficient and promising for the dyes degradation from industrial wastewater as compared with dyes adsorption onto individual NPs. Thus, the nanocomposite NiO/CuO-NC can be an excellent candidate for photodegradation as well as the adsorption of the dyes in aqueous media.

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S. S. dos Santos, Paulo, José M. M. M. de Almeida, Isabel Pastoriza-Santos, and Luís C. C. Coelho. "Advances in Plasmonic Sensing at the NIR—A Review." Sensors 21, no. 6 (March 17, 2021): 2111. http://dx.doi.org/10.3390/s21062111.

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Surface plasmon resonance (SPR) and localized surface plasmon resonance (LSPR) are among the most common and powerful label-free refractive index-based biosensing techniques available nowadays. Focusing on LSPR sensors, their performance is highly dependent on the size, shape, and nature of the nanomaterial employed. Indeed, the tailoring of those parameters allows the development of LSPR sensors with a tunable wavelength range between the ultra-violet (UV) and near infra-red (NIR). Furthermore, dealing with LSPR along optical fiber technology, with their low attenuation coefficients at NIR, allow for the possibility to create ultra-sensitive and long-range sensing networks to be deployed in a variety of both biological and chemical sensors. This work provides a detailed review of the key science underpinning such systems as well as recent progress in the development of several LSPR-based biosensors in the NIR wavelengths, including an overview of the LSPR phenomena along recent developments in the field of nanomaterials and nanostructure development towards NIR sensing. The review ends with a consideration of key advances in terms of nanostructure characteristics for LSPR sensing and prospects for future research and advances in this field.

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Ribeiro, Jomar José Knaip, Paulo Sérgio da Silva Porto, Rodrigo Dias Pereira, and Eduardo Perini Muniz. "Green Synthesis of Nanomaterials: most cited papers and research trends." Research, Society and Development 9, no. 1 (January 1, 2020): e54911593. http://dx.doi.org/10.33448/rsd-v9i1.1593.

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A bibliometric analysis using the Web of Science database was performed on the green synthesis of nanomaterials published between 2003 and 2017, obtaining a sample with a total of 159 publications. The number of citations of each paper, thematic areas, sources of publication and countries of origin were quantified. The ten most cited papers were described in further detail, listing the precursor materials, the kind of material produced among other characteristics. There is a variety of precursors listed in the literature, including fungi, bacteria, plants, extracts from plants and fruits. Although United States was a pioneer and is influent in this line of research, India is taking the lead due to government incentives and the presence of natural resources having a total of 44.65% of the analyzed works. Silver oxides is the material most produced by this method, according to the most cited works and are commonly applied in antibacterial activity. The main areas of discussion at WoS for this topic are the Chemistry and Science Technology categories with 55 papers each. The main sources of publication are the Colloids and Surfaces B - biointerfaces and RSC Advances with 3,774% in each journal in relation to the study sample. Potentialities of the new nanomaterials production method that could be exploited by other researchers from the use of new precursors, including solid agroindustrial wastes, with the opportunity to add value to the biomass and consequently to reduce environmental impact generated by by-products.

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Figueiredo, Bárbara Queiroz de, Álvaro Peixoto de Morais, Ana Clara Viana Soares Brito, Dieison Danrlei Roehrs, Heitor Laborão Carneiro, Isabelle Gomes de Sousa, Letícia de Oliveira Araújo, et al. "Uso do grafeno e nióbio na prática médica: uma revisão narrativa de literatura." Research, Society and Development 11, no. 1 (January 16, 2022): e57911125526. http://dx.doi.org/10.33448/rsd-v11i1.25526.

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Introdução: Os chamados nanomateriais são considerados por muitos, materiais que possuem sua estrutura restrita a dimensões de 1 a 100 nm. Os nanomateriais apresentam uma extensa faixa de aplicações como na biomedicina, na área de alimentos e agricultura, drogas e vacinas e principalmente na catálise. Objetivo: evidenciar as aplicações dos nanomateriais grafeno e nióbio na medicina, ressaltando seus resultados promissores nesse campo. Metodologia: Trata-se de uma pesquisa descritiva do tipo revisão narrativa da literatura. A pesquisa foi realizada através do acesso online nas bases de dados National Library of Medicine (PubMed MEDLINE), Scientific Electronic Library Online (Scielo), Cochrane Database of Systematic Reviews (CDSR), Google Scholar, Biblioteca Virtual em Saúde (BVS) e EBSCO Information Services, no mês de novembro de 2021. Resultados e discussão: O óxido de grafeno reduzido tem se mostrado um excelente agente fototérmico, permitindo a eliminação eficiente de tumores em experimentos in vivo, bem como, devido a excelente condutividade elétrica do grafeno promete melhorar a conversão das sinapses em movimento. Além disso, o uso de nióbio cresce no campo da medicina como elemento de liga para aumento de resistência mecânica para implantes ortopédicos biocompatíveis. Considerações finais: Assim, é possível afirmar que são muitos os benefícios que o grafeno e o nióbio, interligados com as nanotecnologias, gerarão à humanidade, e, principalmente aos avanços da medicina.

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Wang, Kewei, Yanli Li, Haijie Li, Mingyuan Yin, Huilin Liu, Qiliang Deng, and Shuo Wang. "Upconversion fluorescent nanoparticles based-sensor array for discrimination of the same variety red grape wines." RSC Advances 9, no. 13 (2019): 7349–55. http://dx.doi.org/10.1039/c8ra09959f.

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Hamza, Muhammad, Ataf Ali Altaf, Samia Kausar, Shahzad Murtaza, Nasir Rasool, Rukhsana Gul, Amin Badshah, Muhammad Zaheer, Syed Adnan Ali Shah, and Zainul Amiruddin Zakaria. "Catalytic Removal of Alizarin Red Using Chromium Manganese Oxide Nanorods: Degradation and Kinetic Studies." Catalysts 10, no. 10 (October 6, 2020): 1150. http://dx.doi.org/10.3390/catal10101150.

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Dye removal through photocatalytic degradation employing nanomaterials as catalysts is a growing research area. In current studies, photocatalytic alizarin red (AR) dye degradation has been investigated by designing a series of Cr based manganese oxide nanomaterials (MH1–MH5). Synthesized nanomaterials were characterized by powder X-ray diffraction, scanning electron microscopy/energy dispersive x-ray, Brunauer–Emmett–Teller, and photoluminescence techniques and were utilized for photocatalytic AR dye degradation under UV light. AR dye degradation was monitored by UV–visible spectroscopy and percent degradation was studied for the effect of time, catalyst dose, different dye concentrations, and different pH values of dye solution. All the catalysts have shown more than 80% dye degradation exhibiting good catalytic efficiencies for dye removal. The catalytic pathway was analyzed by applying the kinetic model. A pseudo second-order model was found the best fitted kinetic model indicating a chemically-rate controlled mechanism. Values of constant R2 for all the factors studied were close to unity depicting a good correlation between experimental data.

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Shen, Jie, Muhammad Shafiq, Ming Ma, and Hangrong Chen. "Synthesis and Surface Engineering of Inorganic Nanomaterials Based on Microfluidic Technology." Nanomaterials 10, no. 6 (June 17, 2020): 1177. http://dx.doi.org/10.3390/nano10061177.

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The controlled synthesis and surface engineering of inorganic nanomaterials hold great promise for the design of functional nanoparticles for a variety of applications, such as drug delivery, bioimaging, biosensing, and catalysis. However, owing to the inadequate and unstable mass/heat transfer, conventional bulk synthesis methods often result in the poor uniformity of nanoparticles, in terms of microstructure, morphology, and physicochemical properties. Microfluidic technologies with advantageous features, such as precise fluid control and rapid microscale mixing, have gathered the widespread attention of the research community for the fabrication and engineering of nanomaterials, which effectively overcome the aforementioned shortcomings of conventional bench methods. This review summarizes the latest research progress in the microfluidic fabrication of different types of inorganic nanomaterials, including silica, metal, metal oxides, metal organic frameworks, and quantum dots. In addition, the surface modification strategies of nonporous and porous inorganic nanoparticles based on microfluidic method are also introduced. We also provide the readers with an insight on the red blocks and prospects of microfluidic approaches, for designing the next generation of inorganic nanomaterials.

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Xu, Qianzhi, Xiuying Wang, Xiaoli Dong, Chun Ma, Xiufang Zhang, and Hongchao Ma. "Improved Visible Light Photocatalytic Activity for TiO2Nanomaterials by Codoping with Zinc and Sulfur." Journal of Nanomaterials 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/157383.

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S/Zn codoped TiO2nanomaterials were synthesized by a sol-gel method. X-ray diffraction, UV-vis diffuse reflectance spectroscopy, transmission electron microscopy, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy were used to characterize the morphology, structure, and optical properties of the prepared samples. The introduction of Zn and S resulted in significant red shift of absorption edge for TiO2-based nanomaterials. The photocatalytic activity was evaluated by degrading reactive brilliant red X-3B solution under simulated sunlight irradiation. The results showed S/Zn codoped TiO2exhibited higher photocatalytic activity than pure TiO2and commercial P25, due to the photosynergistic effect of obvious visible light absorption, efficient separation of photoinduced charge carriers, and large surface area. Moreover, the content of Zn and S in the composites played important roles in photocatalytic activity of TiO2-based nanomaterials.

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Zhao, Shihua, Huijian Cai, and Peng Li. "Pure Purple Line and Red Line Emissions of ZnO Nanomaterials." Journal of Nanoscience and Nanotechnology 16, no. 7 (July 1, 2016): 7738–41. http://dx.doi.org/10.1166/jnn.2016.13065.

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Lavayen, Vladimir, Daniele Trajano Raupp, Chádia Schissler, Sandra Mara Oliveira Einloft, Leticia Antunes Natividade, and Alef Lemes Vaz. "Síntese e caracterização de nanopartículas de óxido de ferro: Uma proposta de atividade experimental." Research, Society and Development 10, no. 8 (July 12, 2021): e27310817184. http://dx.doi.org/10.33448/rsd-v10i8.17184.

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Este trabalho objetiva apresentar uma metodologia para síntese e caracterização de nanopartículas de óxido de ferro como ferramenta na abordagem de conceitos científicos acerca de nanomateriais para o ensino superior. A justificativa para a inserção de tal atividade experimental nas aulas práticas de química deve-se à revolução que vem ocorrendo pelo desenvolvimento de materiais e dispositivos em escala nanométrica e por seu vasto campo de aplicação. Mais especificamente, as nanopartículas magnéticas têm importância para diversas áreas, pois apresentam potencial de melhoria nas tecnologias de produção, de materiais eletrônicos, no setor de telecomunicações, na biomedicina, na remediação do meio ambiente, entre outros. Utilizando insumos com baixo nível de toxicidade, de fácil acesso e baixo custo, a metodologia proposta usa técnicas de fácil manipulação para obtenção das nanopartículas, bem como ensaios acessíveis para caracterização. Como resultado espera-se que a inserção desta atividade permita a discussão dos conceitos científicos, tecnológicos e sociais relacionados aos nanomateriais, bem como a compreensão do método de precipitação para síntese de nanopartículas, e dos ensaios analíticos para caracterização. Espera-se que esta atividade promova a introdução a conceitos básicos da nanociência e da nanotecnologia, que se fazem presentes no mundo contemporâneo, e que devem ser trazidos para a sala de aula.

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Periasamy, Arun Prakash, Rini Ravindranath, Prathik Roy, Wen-Ping Wu, Huan-Tsung Chang, Pitchaimani Veerakumar, and Shang-Bin Liu. "Carbon–boron core–shell microspheres for the oxygen reduction reaction." Journal of Materials Chemistry A 4, no. 33 (2016): 12987–94. http://dx.doi.org/10.1039/c6ta03684h.

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Carbon nanomaterials (CNMs) with self-assembled carbon microspheres are prepared from red onion skins. The CNMs are further used to prepare carbon–boron core–shell CNMs, which provide high activity for the oxygen reduction reaction (ORR).

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Won, Hansol, Sung-Hyun Kim, Jun-Young Yang, Kikyung Jung, Jayoung Jeong, Jae-Ho Oh, and Jin-Hee Lee. "Colony-Forming Efficiency Assay to Assess Nanotoxicity of Graphene Nanomaterials." Toxics 10, no. 5 (May 5, 2022): 236. http://dx.doi.org/10.3390/toxics10050236.

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The nano-market has grown rapidly over the past decades and a wide variety of products are now being manufactured, including those for biomedical applications. Despite the widespread use of nanomaterials in various industries, safety and health effects on humans are still controversial, and testing methods for nanotoxicity have not yet been clearly established. Nanomaterials have been reported to interfere with conventional cytotoxicity tests due to their unique properties, such as light absorption or light scattering. In this regard, the colony-forming efficacy (CFE) assay has been suggested as a suitable test method for testing some nanomaterials without these color-interferences. In this study, we selected two types of GNPs (Graphene nanoplatelets) as test nanomaterials and evaluated CFE assay to assess the cytotoxicity of GNPs. Moreover, for further investigation, including expansion into other cell types, GNPs were evaluated by the conventional cytotoxicity tests including the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), Cell Counting Kit-8 (CCK-8), and Neutral red uptake (NRU) assay using MDCK, A549 and HepG2 cells. The results of CFE assay suggest that this test method for three cell lines can be applied for GNPs. In addition, the CFE assay was able to evaluate cytotoxicity regardless more accurately of color interference caused by residual nanomaterials.

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Fu, Ding-Yi, Ya-Rong Xue, Yongqing Guo, Zhiyu Qu, Hong-Wei Li, Hui Wu, and Yuqing Wu. "Strong red-emitting gold nanoclusters protected by glutathione S-transferase." Nanoscale 10, no. 48 (2018): 23141–48. http://dx.doi.org/10.1039/c8nr05691a.

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Acosta, Selene, Carlos Moreno-Aguilar, Dania Hernández-Sánchez, Beatriz Morales-Cruzado, Erick Sarmiento-Gomez, Carla Bittencourt, Luis Octavio Sánchez-Vargas, and Mildred Quintana. "A few-layer graphene/chlorin e6 hybrid nanomaterial and its application in photodynamic therapy against Candida albicans." Beilstein Journal of Nanotechnology 11 (July 17, 2020): 1054–61. http://dx.doi.org/10.3762/bjnano.11.90.

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The global emergence of multidrug resistance of fungal infections and the decline in the discovery of new antibiotics are increasingly prevalent causes of hospital-acquired infections, among other major challenges in the global health care sector. There is an urgent need to develop noninvasive, nontoxic, and new antinosocomial approaches that work more effectively and faster than current antibiotics. In this work, we report on a biocompatible hybrid nanomaterial composed of few-layer graphene and chlorin e6 (FLG-Ce6) for the photodynamic treatment (PDT) of Candida albicans. We show that the FLG-Ce6 hybrid nanomaterial displays enhanced reactive oxygen species (ROS) generation compared with Ce6. The enhancement is up to 5-fold when irradiated for 15 min at 632 nm with a red light-emitting diode (LED). The viability of C. albicans in the presence of FLG-Ce6 was measured 48 h after photoactivation. An antifungal effect was observed only when the culture/FLG-Ce6 hybrid was exposed to the light source. C. albicans is rendered completely unviable after exposure to ROS generated by the excited FLG-Ce6 hybrid nanomaterial. An increased PDT effect was observed with the FLG-Ce6 hybrid nanomaterial by a significant reduction in the viability of C. albicans, by up to 95%. This is a marked improvement compared to Ce6 without FLG, which reduces the viability of C. albicans to only 10%. The antifungal action of the hybrid nanomaterial can be activated by a synergistic mechanism of energy transfer of the absorbed light from Ce6 to FLG. The novel FLG-Ce6 hybrid nanomaterial in combination with the red LED light irradiation can be used in the development of a wide range of antinosocomial devices and coatings.

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Nunes, Marcela Trojahn, Fabiele Schaefer Rodrigues, and Jocenir Boita. "Nanomateriais à base de óxidos de ferro suportados com resíduos ricos em sílica." Ciência e Natura 40 (March 12, 2019): 225. http://dx.doi.org/10.5902/2179460x35524.

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Nanoparticles can be obtained through different chemical components, such as iron oxides that have the advantages of easy synthesis, low toxicity, biocompatibility, high adsorption capacity and low cost. Since, the NPs have quite peculiar characteristics differing significantly from other materials mainly by the increase of the surface area and also by the quantum effects. The objective of this work is to obtain Nanomaterials based on iron oxides supported by different residues (rice husk ash, red ceramics and agate), composed mostly of SiO2, using the polyol method, and to evaluate the possibility of using them in different applications, for example, in the field of catalysis and in various engineering processes. The Nanomaterials were characterized with experimental techniques existing in the National Synchrotron Light Laboratory (LNLS), which allow the electronic and structural investigation of Nanomaterials such as X-ray Induced Photoelectron Spectroscopy (XPS). The study allowed to identify that it was possible to use residues with SiO2 in the obtaining of NPs, as well as, confirmed that there is differentiation in their structure. Enabling the expansion of studies in relation to the application of these Nanomaterials.

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Gupta, Mohini, Rajamani Nagarajan, Chitteti Ramamurthy, Perumal Vivekanandan, and G. Vijaya Prakash. "KLa(0.95−x)GdxF4:Eu3+ hexagonal phase nanoparticles as luminescent probes for in vitro Huh-7 cancer cell imaging." Dalton Transactions 50, no. 15 (2021): 5197–207. http://dx.doi.org/10.1039/d1dt00539a.

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Strong and site selective red-emitting photoluminescent/MRI multi-functional KLa_(0.95−x)Gd_xF₄:Eu³⁺ (x = 0–0.4) bio-compatible nanomaterials for targeted in-vitro liver cancer cell imaging.

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Hyppänen, Iko, Jorma Hölsä, Jouko Kankare, Mika Lastusaari, and Laura Pihlgren. "Upconversion Properties of Nanocrystalline ZrO2:Yb3+, Er3+Phosphors." Journal of Nanomaterials 2007 (2007): 1–8. http://dx.doi.org/10.1155/2007/16391.

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Combustion and sol-gel methods were used to prepare the upconverting nanocrystallineZrO2:Yb3+,Er3+phosphors. The crystal structure was studied by X-ray powder diffraction and the crystallite sizes were estimated with the Scherrer formula. Impurities and nanomaterials' thermal degradation were analyzed with FT-IR spectroscopy and thermal analysis, respectively. Upconversion luminescence and luminescence decays were studied with IR-laser excitation at 977 nm. All nanomaterials possessed the cubicZrO2fluorite-type structure except for a small monoclinic impurity obtained with the sol-gel method. The conventionalNO3−andOH−impurities were observed for the combustion synthesis products. TheZrO2:Yb3,Er3+nanomaterials showed red (630–710 nm) and green (510–570 nm) upconversion luminescence due to the4F9/2→4I15/2and(2H11/2,4S3/2)→4I15/2transitions ofEr3+, respectively. The products of the combustion synthesis exhibited the most intense luminescence intensity and showed considerable afterglow. It was concluded that excitation energy is partially trapped in the system and subsequently bleached thermally to the luminescentEr3+center to yield “persistent upconversion”.

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Pereira, Renata Aparecida, Lisia Maria Gobbo dos Santos, Cristiane Barata Silva, André Luiz Oliveira da Silva, and Silvana do Couto Jacob. "O uso de fibras têxteis impregnadas com nanopartículas de prata para enfretamento de doenças infeciosas, seus riscos à saúde e a sua regulação sanitária." Research, Society and Development 11, no. 6 (April 20, 2022): e7311628704. http://dx.doi.org/10.33448/rsd-v11i6.28704.

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Introdução: O surgimento da pandemia causada pelo novo Coronavírus, tem se tornado um dos grandes desafios do século XXI. O uso da nanotecnologia em fibras têxteis tem potencial para se tornar um recurso para o enfretamento da pandemia. Nesse campo, merecem destaque os tecidos impregnados com nanopartículas de prata (AgNP), graças a seus atributos antivirais e anrtibacterianos. Objetivos: Essa revisão integrativa visou avaliar suas aplicações, eficácia antimicrobiana, riscos e regulação de forma a contribuir ao combate a pandemia de COVID-19, assim como de outras doenças infeciosas. Metodologia: Para a realização desse estudo foram realizadas buscas na literatura. Resultados e Discussão: Os resultados demonstraram que as AgNPs impregnadas em tecidos podem ter uma ampla aplicação no campo médico. A literatura apontou também uma relevante capacidade antimicrobiana das AgNPs, contudo essa capacidade parece ter relação com seu diâmetro e forma. Grande parte dos nanomateriais são classificados como GRAS, entretanto essa classificação foi feita pela extrapolação dos dados obtidos em formas não nanométricas. De maneira geral as informações sobre a biodisponibilidade e toxicocinética de nanomateriais são pouco conhecidas. Em termos regulatórios, apesar de avanços recentes, trata-se de um tema ainda em discussão. Conclusões: Apesar de ainda existirem muitas lacunas regulatórias no tema, o uso das AgNP, não somente em fibras têxteis, pode se tornar um recurso valioso, não somente para o enfrentamento da pandemia de COVD-19, mas como de outras doenças causadas por microrganismos.

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Celedón, Salvador, Andrea S. S. de Camargo, Mauricio Fuentealba, Vania Artigas, Eglantina Benavente, and Guillermo González. "Highly emissive host–guest based on nanoclay intercalated with an Eu3+ complex bearing a new Ru2+ organometallic ligand." New Journal of Chemistry 42, no. 18 (2018): 15284–94. http://dx.doi.org/10.1039/c8nj02432d.

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Stopikowska, Natalia, Marcin Runowski, Przemysław Woźny, Stefan Lis, and Peng Du. "Generation of Pure Green Up-Conversion Luminescence in Er3+ Doped and Yb3+-Er3+ Co-Doped YVO4 Nanomaterials under 785 and 975 nm Excitation." Nanomaterials 12, no. 5 (February 26, 2022): 799. http://dx.doi.org/10.3390/nano12050799.

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Materials that generate pure, single-color emission are desirable in the development and manufacturing of modern optoelectronic devices. This work shows the possibility of generating pure, green up-conversion luminescence upon the excitation of Er3+-doped nanomaterials with a 785 nm NIR laser. The up-converting inorganic nanoluminophores YVO4: Er3+ and YVO4: Yb3+ and Er3+ were obtained using a hydrothermal method and subsequent calcination. The synthesized vanadate nanomaterials had a tetragonal structure and crystallized in the form of nearly spherical nanoparticles. Up-conversion emission spectra of the nanomaterials were measured using laser light sources with λex = 785 and 975 nm. Importantly, under the influence of the mentioned laser irradiation, the as-prepared samples exhibited bright green up-conversion luminescence that was visible to the naked eye. Depending on the dopant ions used and the selected excitation wavelengths, two (green) or three (green and red) bands originating from erbium ions appeared in the emission spectra. In this way, by changing the UC mechanisms, pure green luminescence of the material can be obtained. The proposed strategy, in combination with various single-doped UC nanomaterials activated with Er3+, might be beneficial for modern optoelectronics, such as light-emitting diodes with a rich color gamut for back-light display applications.

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Jiao, Yang, Yimin Guo, Yingcong Fan, Rui Wang, Xiang Li, Hao Wu, Zhichao Meng, et al. "Triggering of Apoptosis in Osteosarcoma 143B Cell Line by Carbon Quantum Dots via the Mitochondrial Apoptotic Signal Pathway." BioMed Research International 2020 (July 11, 2020): 1–12. http://dx.doi.org/10.1155/2020/2846297.

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Objectives. Carbon-based nanomaterials have gained attention in the field of biomedicine in recent years, especially for the treatment of complicated diseases such as cancer. Here, we report a novel carbon-based nanomaterial, named carbon quantum dots (CQDs), which has potential for cancer therapy. We performed a systematic study on the effects of CQDs on the osteosarcoma 143B cell line in vitro and in vivo. Methods. Cell counting assay, the neutral red assay, lactic dehydrogenase assay, and fluorescein isothiocyanate (FITC) Annexin V/Propidium iodide (PI) were used to detect the cytotoxicity and apoptosis of CQDs on the 143B cell line. Intracellular reactive oxygen species (ROS) were detected by the oxidation-sensitive fluorescent probe 2′,7′-dichlorofluorescein diacetate. The JC-10 assay was used to detect the mitochondrial membrane potential (MMP) of 143B cells incubated with CQDs. The effects of CQDs on the 143B cell line were evaluated by Western blot and immunofluorescence analysis of apoptosis-related proteins Bax, Bcl-2, cytochrome-C, caspase-3, cleaved-caspase-3, PARP1, and cleaved-PARP1. Male tumor-bearing BALB/c nude mice were used to investigate the antitumor effects of CQDs, and the biosafety of CQDs in vivo was tested in male BALB/c mice by measuring weight changes, hematology tests, and histological analyses of major organs. Results. CQDs exhibited a high cytotoxicity and induced apoptosis toward the 143B cell line. CQDs can also significantly increase the intracellular level of ROS and lower the mitochondrial membrane potential levels of 143B cells. CQDs increase apoptotic protein expression to induce apoptosis of 143B cells by triggering the mitochondrial apoptotic signaling pathway. The tumor volume in the CQD-treated mice was smaller than that in the control group, the tumor volume inhibition rate was 38.9%, and the inhibitory rate by tumor weight was 30.1%. All biosafety test indexes were within reference ranges, and neither necrosis nor inflammation was observed in major organs. Conclusions. CQDs induced cytotoxicity in the 143B cell line through the mitochondrial apoptotic signaling pathway. CQDs not only showed an antitumor effect but also high biocompatibility in vivo. As a new carbon-based nanomaterial, CQDs usage is a promising method for novel cancer treatments.

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Irazusta, Silvia Pierre, Marjorie Stempliuk Ferreira, Paulo José Balsamo, Larissa Solano de Almeida, and Helder José Ceragioli. "Toxicidade e possível interação celular do Óxido de Grafeno Reduzido com Raphidoceles subcapitata: Análise ultraestrutural." Research, Society and Development 10, no. 15 (November 24, 2021): e459101520377. http://dx.doi.org/10.33448/rsd-v10i15.20377.

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O óxido de grafeno reduzido (rGO) é um nanomaterial formado por carbono, apresentado como um derivado do óxido de grafeno e, devido às suas propriedades, é utilizado em áreas como microeletrônica, mecânica e biomedicina. Apesar da grande quantidade de testes realizados com esse nanomaterial, ainda não há consenso sobre sua toxicidade, quando no meio ambiente. O meio aquático costuma ser o destino final desses compostos e, por isso, as algas verdes costumam ser utilizadas como bioindicador. Este estudo teve como objetivo determinar a ecotoxicidade e possíveis interações da nanopartícula de rGO com a célula de algas verdes de Raphidocelis subcapitata. As alterações estruturais nas algas, expostas a diferentes concentrações a rGO, foram analisadas através de microscopia eletrônica de transmissão (TEM) e espectroscopia Raman, a toxicidade foi avaliada por meio da medida de inibição da biomassa algal. Os resultados indicam que não houve efeito tóxico no organismo estudado, exceto na maior concentração (100 mg.L-1). A análise de TEM demonstrou uma interação das nanopartículas com a célula algal, pela observação da internalização das nanopartículas, bem como pela deposição de rGO na membrana celular. Apesar da ausência de toxicidade em baixas concentrações, os organismos mostraram sensibilidade à presença do rGO. Esses resultados contribuem com a literatura no esclarecimento do comportamento das nanopartículas à base de carbono no ambiente aquático e podem permitir um melhor cuidado com a produção e liberação dessas nanopartículas no meio ambiente.

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Meng, Di, Shuoye Yang, Yanan Yang, Lu Zhang, and Lan Cui. "Synergistic chemotherapy and phototherapy based on red blood cell biomimetic nanomaterials." Journal of Controlled Release 352 (December 2022): 146–62. http://dx.doi.org/10.1016/j.jconrel.2022.10.019.

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Guan, Hongxia, Yanhua Song, Keyan Zheng, Ye Sheng, and Haifeng Zou. "BaGdF5:Dy3+,Tb3+,Eu3+ multifunctional nanospheres: paramagnetic, luminescence, energy transfer, and tunable color." Physical Chemistry Chemical Physics 18, no. 20 (2016): 13861–73. http://dx.doi.org/10.1039/c6cp01798c.

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The photoluminescence emission color tones of BaGdF₅:Dy³⁺,Tb³⁺,Eu³⁺ nanomaterials change from yellow-green to red by adjusting the doping concentration and the different excitation wavelengths. Furthermore, the obtained samples also exhibit paramagnetic properties.

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Rajaramanan, Tharmakularasa, Sivagowri Shanmugaratnam, Vijayakumar Gurunanthanan, Shivatharsiny Yohi, Dhayalan Velauthapillai, Punniamoorthy Ravirajan, and Meena Senthilnanthanan. "Cost Effective Solvothermal Method to Synthesize Zn-Doped TiO2 Nanomaterials for Photovoltaic and Photocatalytic Degradation Applications." Catalysts 11, no. 6 (May 29, 2021): 690. http://dx.doi.org/10.3390/catal11060690.

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Titanium dioxide (TiO2) is a commonly used wide bandgap semiconductor material for energy and environmental applications. Although it is a promising candidate for photovoltaic and photocatalytic applications, its overall performance is still limited due to low mobility of porous TiO2 and its limited spectral response. This limitation can be overcome by several ways, one of which is doping that could be used to improve the light harvesting properties of TiO2 by tuning its bandgap. TiO2 doped with elements, such as alkali-earth metals, transition metals, rare-earth elements, and nonmetals, were found to improve its performance in the photovoltaic and photocatalytic applications. Among the doped TiO2 nanomaterials, transition metal doped TiO2 nanomaterials perform efficiently by suppressing the relaxation and recombination of charge carriers and improving the absorption of light in the visible region. This work reports the possibility of enhancing the performance of TiO2 towards Dye Sensitised Solar Cells (DSSCs) and photocatalytic degradation of methylene blue (MB) by employing Zn doping on TiO2 nanomaterials. Zn doping was carried out by varying the mole percentage of Zn on TiO2 by a facile solvothermal method and the synthesized nanomaterials were characterised. The XRD (X-Ray Diffraction) studies confirmed the presence of anatase phase of TiO2 in the synthesized nanomaterials, unaffected by Zn doping. The UV-Visible spectrum of Zn-doped TiO2 showed a red shift which could be attributed to the reduced bandgap resulted by Zn doping. Significant enhancement in Power Conversion Efficiency (PCE) was observed with 1.0 mol% Zn-doped TiO2 based DSSC, which was 35% greater than that of the control device. In addition, it showed complete degradation of MB within 3 h of light illumination and rate constant of 1.5466×10−4s−1 resembling zeroth order reaction. These improvements are attributed to the reduced bandgap energy and the reduced charge recombination by Zn doping on TiO2.

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Bandi, Sirisha, Phani Raja Kanuparthy, and Venkata Nagendra Kumar Putta. "Dual Mode Photoluminescence Studies of Polyol-mediated Ho3+ Doped CePO4." Oriental Journal Of Chemistry 39, no. 4 (August 30, 2023): 890–95. http://dx.doi.org/10.13005/ojc/390409.

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In this work, CePO4:Ho3+ nanomaterials are prepared by a productive polyol method which shows the dual mode of behavior in Photoluminescence. The up-conversion spectra at 980 nm excitation display a sharp brilliant peak at ∼520nm - ∼550nm, ∼630 nm, - 670 nm resulting in the (5F4,5S2→5I8) and (5F5→5I8) of Ho3+ ions, and it is also found that the sample radiates green and red colors. The down-conversion peaks show maximum absorption at 300nm which exhibit peaks at ∼450nm, ∼520nm- ∼550 nm, ∼and 630 nm -∼670 nm respectively. the rare earth ions doped nanomaterials show up-conversion radiation and down-conversion radiation. This type of energetic work has an extensive range of applications, including lasers, metal ion sensors, bio-imaging, temperature and stress sensors, radiation damage sensors, and defense and cyber security.

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Zhu, Xiaohua, Xiao Pang, Youyu Zhang, and Shouzhuo Yao. "Titanium carbide MXenes combined with red-emitting carbon dots as a unique turn-on fluorescent nanosensor for label-free determination of glucose." Journal of Materials Chemistry B 7, no. 48 (2019): 7729–35. http://dx.doi.org/10.1039/c9tb02060h.

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Titanium carbides (Ti₃C₂), a new family of two-dimensional (2D) nanomaterials, have attracted extensive attention due to their unique structure and desirable physiochemical properties.

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Silveira, Maria Laura Della Costa, Nathalia Rodrigues da Silva, David Santos Souza Padovini, Angela Kinoshita, Fenelon Martinho Lima Pontes, and Aroldo Geraldo Magdalena. "Synthesis, characterization, and photocatalytic activity of ZnO nanostructures." Research, Society and Development 11, no. 2 (January 17, 2022): e3811225373. http://dx.doi.org/10.33448/rsd-v11i2.25373.

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This study investigated the synthesis, characterization of ZnO nanostructures using different precipitating agents in the photodegradation of rhodamine B (Rh B) using scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier transform infrared (FTIR) and UV/Vis spectroscopy and zeta potential measurements. The results indicated the dependence of morphology on calcination temperature and the precipitating agent. The colloidal stability of these nanomaterials is affected with the morphology changed. The photocatalytic results showed that ZnO nanostructures synthesized with NH4OH (98.98%) were more efficient in the degradation of Rh B than ZnO nanostructures synthesized with NaOH (62.68%). This is related to ZnO (NH4OH) nanoparticles should present a higher density of electronic defects than ZnO (NaOH), producing energy levels between the band gaps. These results are potentially associated with a combination of optical and geometric factors that create other paths for the generation of electron-hole pairs in the precipitated ZnO nanocatalyst with different alkaline solutions.

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Wei, Tian, Yingdong Han, Yang Wei, Chao Gao, Hui Ma, Fan Zhang, Shuyi Bao, Su Jing, and Ling Huang. "CaSc2O4 hosted upconversion and downshifting luminescence." Journal of Materials Chemistry C 9, no. 11 (2021): 3800–3805. http://dx.doi.org/10.1039/d1tc00239b.

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Nanomaterials of CaSc₂O₄:Yb/Ln (Ln = Tb, Eu) were investigated for dual-mode luminescence generation, where strong upconversion with a green/red intensity ratio as high as 45 and downshifting blue emissions were obtained at the characteristic working wavelengths of Yb³⁺ (980 nm) and Tb³⁺ (280 nm), respectively.

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Lee, Eun Sung, Byung Seok Cha, Seokjoon Kim, and Ki Soo Park. "Synthesis of Exosome-Based Fluorescent Gold Nanoclusters for Cellular Imaging Applications." International Journal of Molecular Sciences 22, no. 9 (April 23, 2021): 4433. http://dx.doi.org/10.3390/ijms22094433.

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In recent years, fluorescent metal nanoclusters have been used to develop bioimaging and sensing technology. Notably, protein-templated fluorescent gold nanoclusters (AuNCs) are attracting interest due to their excellent fluorescence properties and biocompatibility. Herein, we used an exosome template to synthesize AuNCs in an eco-friendly manner that required neither harsh conditions nor toxic chemicals. Specifically, we used a neutral (pH 7) and alkaline (pH 11.5) pH to synthesize two different exosome-based AuNCs (exo-AuNCs) with independent blue and red emission. Using field-emission scanning electron microscopy, energy dispersive X-ray microanalysis, nanoparticle tracking analysis, and X-ray photoelectron spectroscopy, we demonstrated that AuNCs were successfully formed in the exosomes. Red-emitting exo-AuNCs were found to have a larger Stokes shift and a stronger fluorescence intensity than the blue-emitting exo-AuNCs. Both exo-AuNCs were compatible with MCF-7 (human breast cancer), HeLa (human cervical cancer), and HT29 (human colon cancer) cells, although blue-emitting exo-AuNCs were cytotoxic at high concentrations (≥5 mg/mL). Red-emitting exo-AuNCs successfully stained the nucleus and were compatible with membrane-staining dyes. This is the first study to use exosomes to synthesize fluorescent nanomaterials for cellular imaging applications. As exosomes are naturally produced via secretion from almost all types of cell, the proposed method could serve as a strategy for low-cost production of versatile nanomaterials.

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Murdock, Richard C., Omar A. Khan, Thomas J. Lamkin, Saber M. Hussain, and Nancy Kelley-Loughnane. "Hybridization State Detection of DNA-Functionalized Gold Nanoparticles Using Hyperspectral Imaging." International Journal of Optics 2017 (2017): 1–12. http://dx.doi.org/10.1155/2017/8427459.

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Hyperspectral imaging has the unique ability of capturing spectral data for multiple wavelengths at each pixel in an image. This gives the ability to distinguish, with certainty, different nanomaterials and/or distinguish nanomaterials from biological materials. In this study, 4 nm and 13 nm gold nanoparticles (Au NPs) were synthesized, functionalized with complimentary oligonucleotides, and hybridized to form large networks of NPs. Scattering spectra were collected from each sample (unfunctionalized, functionalized, and hybridized) and evaluated. The spectra showed unique peaks for each size of Au NP sample and also exhibited narrowing and intensifying of the spectra as the NPs were functionalized and then subsequently hybridized. These spectra are different from normal aggregation effects where the LSPR and reflected spectrum broaden and are red-shifted. Rather, this appears to be dependent on the ability to control the interparticle distance through oligonucleotide length, which is also investigated through the incorporation of a poly-A spacer. Also, hybridized Au NPs were exposed to cells with no adverse effects and retained their unique spectral signatures. With the ability to distinguish between hybridization states at nearly individual NP levels, this could provide a new method of tracking the intracellular actions of nanomaterials as well as extracellular biosensing applications.

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Dăscălescu, Dorin, and Constantin Apetrei. "Nanomaterials Based Electrochemical Sensors for Serotonin Detection: A Review." Chemosensors 9, no. 1 (January 14, 2021): 14. http://dx.doi.org/10.3390/chemosensors9010014.

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The present review deals with the recent progress made in the field of the electrochemical detection of serotonin by means of electrochemical sensors based on various nanomaterials incorporated in the sensitive element. Due to the unique chemical and physical properties of these nanomaterials, it was possible to develop sensitive electrochemical sensors with excellent analytical performances, useful in the practice. The main electrochemical sensors used in serotonin detection are based on carbon electrodes modified with carbon nanotubes and various materials, such as benzofuran, polyalizarin red-S, poly(L-arginine), Nafion/Ni(OH)2, or graphene oxide, incorporating silver-silver selenite nanoparticles, as well as screen-printed electrodes modified with zinc oxide or aluminium oxide. Also, the review describes the nanocomposite sensors based on conductive polymers, tin oxide-tin sulphide, silver/polypyrole/copper oxide or a hybrid structure of cerium oxide-gold oxide nanofibers together with ruthenium oxide nanowires. The presentation focused on describing the sensitive materials, characterizing the sensors, the detection techniques, electroanalytical properties, validation and use of sensors in lab practice.

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Journal articles on the topic 'RGD nanomaterials'

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