scholarly journals Computed Tomography Imaging Agent Based on Gold Nanoparticles for Internal Iliac Artery Embolization after Endovascular Abdominal Aortic Repair and CCN3 Protection Mechanism

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Siying Pei ◽  
Yao Sun ◽  
Dongxu Fan ◽  
Shuhua Deng ◽  
Haoran Mei ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Near Infrared ◽  
Infrared Region ◽  
Fluorescent Properties ◽  
Protection Mechanism ◽  
Abdominal Aortic ◽  
Infrared Rays ◽  
Growth Method ◽  
Internal Iliac ◽  
Endovascular Abdominal Aortic Repair

Abdominal aortic aneurysm is more stressful and has more complications in many diseases. During treatment and repair, arteriosclerosis, abdominal congestion deposition, and abdominal swelling cannot be eliminated. In this paper, we used the seed growth method to obtain gold nanoparticles (AuNPs) with good morphology and dispersion. The AuNPs of larger aspect ratio synthesized in this experiment moved their longitudinal plasmon resonance absorption peak to the near-infrared region, which provided suitable materials for subsequent experiments and laid the foundation for the photothermal therapy of tumors. Experiments show that near-infrared rays can penetrate into deep tissues to overcome the shortcomings that visible light cannot penetrate abdominal aorta well. AuNPs absorb near-infrared rays, thereby generating heat energy to achieve the purpose of treating tumors. In addition, AuNPs also have fluorescent properties, combined with other forms of imaging methods, to achieve the purpose of multimodal imaging, and improve the diagnostic accuracy of studying the protection mechanism of the nephroblastoma overexpressed (NOV or CCN3) gene.

scholarly journals Experimental setup for light-to-heat NIR conversion measurements of gold nano-particles’ solutions

2018 ◽  
Vol 5 (2) ◽  
pp. 38-47
Author(s):  
Nikolay Uzunov ◽  
Michele Bello ◽  
Laura Melendez-Alafort ◽  
Laura De Nardo
Keyword(s):  
Gold Nanoparticles ◽  
Near Infrared ◽  
Laser System ◽  
Fluorescence Emission ◽  
Ambient Air ◽  
Infrared Region ◽  
Nano Particles ◽  
Fixed Temperature ◽  
Electronic Temperature ◽  
Cuvette Holder

Abstract In recent years, there is a constantly increasing interest in the application of nanoparticles for cancer diagnosis and cancer therapy. In this respect, the most promising nano-objects at present are the gold nanoparticles. A very convenient and powerful property of these objects is their ability to increase their temperature under electro-magnetic irradiation with certain wavelength. In our research we have directed our efforts toward particular nano-objects specifically sensitive to electromagnetic radiation in the near-infrared region (NIR). In order to study the photothermic properties of the solutions of gold nanoparticles in the NIR we constructed a specific electronic setup consisting of a laser system with interchangeable laser diodes with different wavelength NIR light, a thermally-insulated cuvette-holder compartment with temperature measuring probes and a NIR spectrometer to control the stimulated fluorescence emission of the nanoparticles’ solutions. The temperature measurement compartment with the thermal-insulated cuvette holder was designed to maintain the solutions’ temperature at a fixed value right before the moment of laser irradiation. To maintain the measurement setup at a fixed temperature before the irradiation we used a thermal stabilized system based on two Peltier cells with electronic temperature control. The temperatures of the ambient air and the temperature of the cuvette walls were continuously measured in order to make corrections about the temperature dissipation during the irradiation.

Synthesis of π-expanded BODIPYs and their fluorescent properties in the visible–near–infrared region

Tetrahedron ◽  
2010 ◽  
Vol 66 (34) ◽  
pp. 6895-6900 ◽  
Author(s):  
Tetsuo Okujima ◽  
Yuya Tomimori ◽  
Jun Nakamura ◽  
Hiroko Yamada ◽  
Hidemitsu Uno ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Region ◽  
Fluorescent Properties ◽  
Near Infrared Region

scholarly journals Preliminary Assays towards Melanoma Cells Using Phototherapy with Gold-Based Nanomaterials

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1536
Author(s):  
Joana Lopes ◽  
João Miguel Pinto Coelho ◽  
Pedro Manuel Cardoso Vieira ◽  
Ana Silveira Viana ◽  
Maria Manuela Gaspar ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Cell Lines ◽  
Complex Disease ◽  
Near Infrared ◽  
Infrared Region ◽  
Melanoma Cells ◽  
Therapeutic Window ◽  
New Paradigm ◽  
Skin Cells ◽  
Mean Size

Cancer like melanoma is a complex disease, for which standard therapies have significant adverse side effects that in most cases are ineffective and highly unspecific. Thus, a new paradigm has come with the need of achieving alternative (less invasive) and effective therapies. In this work, biocompatible gold nanoparticles (GNPs) coated with hyaluronic acid and oleic acid were prepared and characterized in terms of size, morphology and cytotoxicity in the presence of Saccharomyces cerevisiae, and two cell lines, the keratinocytes (healthy skin cells, HaCat) and the melanoma cells (B16F10). Results showed that these GNPs absorb within the near-infrared region (750–1400 nm), in the optical therapeutic window (from 650 to 1300 nm), in contrast to other commercial gold nanoparticles, which enables light to penetrate into deep skin layers. A laser emitting in this region was applied and its effect also analyzed. The coated GNPs showed a spherical morphology with a mean size of 297 nm without cytotoxic effects towards yeast and tested cell lines. Nevertheless, after laser irradiation, a reduction of 20% in B16F10 cell line viability was observed. In summary, this work appears to be a promising strategy for the treatment of non-metastatic melanoma or other superficial tumors.

scholarly journals SARS-CoV-2 Detection using Colorimetric Plasmonic Sensors: A Proof-of-Concept Computational Study

2021 ◽  
Author(s):  
Somen Baidya ◽  
Ahmed M Hassan
Keyword(s):  
Gold Nanoparticles ◽  
Outer Surface ◽  
Near Infrared ◽  
Computational Study ◽  
Visible Spectrum ◽  
Resonance Wavelength ◽  
Infrared Region ◽  
Molecular Techniques ◽  
Visible Range ◽  
Broadband Absorption

Traditional molecular techniques for SARS-CoV-2 viral detection are time-consuming and can exhibit a high probability of false negatives. In this work, <a>we present a computational study of SARS-CoV-2 detection using plasmonic gold nanoparticles</a>. The resonance wavelength of a SARS-CoV-2 virus was recently estimated to be in the near-infrared region. By engineering gold nanospheres to specifically bind with the outer surface of the SARS-CoV-2 virus, the resonance frequency can be shifted to the visible range (380 nm – 700 nm). Moreover, we show that broadband absorption will emerge in the visible spectrum when the virus is partially covered with gold nanoparticles at a specific coverage percentage. This broadband absorption can be used to guide the development of an efficient and accurate colorimetric plasmon sensor for COVID-19 detection. Our observation also suggests that this technique is unaffected by the number of protein spikes present on the virus outer surface, hence can pave a potential path for a diagnostic tool independent on the number of protein spikes.

Infrared Spectra of Cured and Uncured Rubbers

1959 ◽  
Vol 32 (2) ◽  
pp. 628-638
Author(s):  
G. A. Blokh ◽  
A. F. Mal'nev
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared ◽  
Infrared Absorption Spectrum ◽  
Infrared Region ◽  
Absorption Bands ◽  
Linear Absorption ◽  
Infrared Rays ◽  
Other Substances ◽  
The Individual

Abstract The newest physical-chemical methods of research enlarge the scope of study of the vulcanization process. There is a possibility of studying the structure changes during vulcanization of rubber by the application of infrared spectroscopy. Infrared rays are selectively absorbed. Therefore the infrared absorption spectrum can be used as a characteristic property of a substance and could be used for analytical purposes. The large spectral range of the infrared rays indicates their importance for the study of the properties and structure of substances; this makes possible the determination of the moments of inertia of atomic nuclei and molecules, isotopic mass, arrangement and strength of atomic bonds in the molecule and the frequencies of their vibrations. By knowing the frequencies for pure substances, molecular analyses of complicated mixtures of various organic rubbers, accelerators and other substances could be performed. The study of linear absorption spectra is the basis of the spectrographic method in the infrared region. Since the frequencies of near infrared radiation correspond to the characteristic frequencies of the atoms in the molecules, this method could be used to obtain interesting information concerning the structure of organic molecules, the chemical structure of high molecular weight compounds, the determination of the presence of specific groups or atoms in the rubber molecule, the character of the bonds between these groups and the order of arrangement of the individual chain links. This is true because the position of the absorption bands, which are specific for a given group of atoms, is practically the same for the different combinations in which the group occurs. The complicated process of polymerization of diene and vinyl compounds and the structure of different types of rubbers can be investigated with the aid of infrared spectroscopy. For example, Table I lists the characteristic absorption frequencies in the infrared region for some important chemical combinations.

scholarly journals SERS, XPS and DFT Study of Xanthine Adsorbed on Citrate-Stabilized Gold Nanoparticles

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2700 ◽  
Author(s):  
Stefano Caporali ◽  
Francesco Muniz-Miranda ◽  
Alfonso Pedone ◽  
Maurizio Muniz-Miranda
Keyword(s):  
Gold Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Density Functional ◽  
Near Infrared ◽  
Fluorescence Emission ◽  
Colloidal Suspensions ◽  
Infrared Region ◽  
Chloride Ions ◽  
Surface Enhanced Raman

We have studied the adsorption of xanthine, a nucleobase present in human tissue and fluids that is involved in important metabolic processes, on citrate-reduced gold colloidal nanoparticles by means of surface-enhanced Raman scattering (SERS), absorption, and X-ray photoelectron spectroscopy (XPS) measurements, along with density functional theory (DFT) calculations. The citrate anions stabilize the colloidal suspensions by strongly binding the gold nanoparticles. However, these anions do not impair the adsorption of xanthine on positively-charged active sites present on the metal surface. We have obtained the Fourier transform (FT)-SERS spectra of adsorbed xanthine by laser excitation in the near infrared spectral region, where interference due to fluorescence emission does not usually occur. In fact, the addition of chloride ions to the Au/xanthine colloid induces the aggregation of the gold nanoparticles, whose plasmonic band is shifted to the near infrared region where there is the exciting laser line of the FT–Raman instrument. Hence, this analytical approach is potentially suitable for spectroscopic determination of xanthine directly in body fluids, avoiding fluorescence phenomena induced by visible laser irradiation.

Blocking Properties of Superparamagnetic Magnetite Nanoparticles and Gold/Superparamagnetic Magnetite Composite Nanoparticles

2015 ◽  
Vol 1108 ◽  
pp. 15-20 ◽  
Author(s):  
Bashiru Kayode Sodipo ◽  
Azlan Abdul Aziz
Keyword(s):  
Gold Nanoparticles ◽  
Magnetite Nanoparticles ◽  
Visible Region ◽  
Infrared Region ◽  
The Other ◽  
Composite Nanoparticles ◽  
Protective Properties ◽  
Amine Functionalized ◽  
Infrared Rays ◽  
Gold Precursor

The UV and IR block properties of superparamagnetic magnetite nanoparticles (SPMN) and SPMN/gold composite nanoparticles are investigated. The composite nanoparticles were prepared via sonochemical assisted reduction of gold precursor and deposition of gold nanoparticles (GNP) on amine functionalized SPMN. Protective properties of the SPMN and the composite nanoparticles were demonstrated via spectrophotometer measurements. Unlike in the visible and infrared region, there was 0% transmission of radiation through bare SPMN in the UV region. The presence GNP in the composites nanoparticles affects the protecting properties of the SPMN with almost 40% transmission in the UV region. The SPMN/GNP composite nanoparticles were able to block some radiation in the visible region. On the other hand, there was nearly uniform 90% and continuous transmission of infrared rays in naked SPMN and SPMN/GNP composite nanoparticles, respectively.

scholarly journals Experimental setup for light-to-heat NIR conversion measurements of gold nanoparticle solutions

2019 ◽  
Vol 6 (1) ◽  
pp. 91-99
Author(s):  
Nikolay Uzunov ◽  
Michele Bello ◽  
Laura Melendez-Alafort ◽  
Laura De Nardo
Keyword(s):  
Gold Nanoparticles ◽  
Near Infrared ◽  
Laser System ◽  
Fluorescence Emission ◽  
Ambient Air ◽  
Infrared Region ◽  
Fixed Temperature ◽  
Electronic Temperature ◽  
Cuvette Holder ◽  
Electro Magnetic

Abstract In recent years, there is a constantly increasing interest in the application of nanoparticles for cancer diagnosis and cancer therapy. In this respect, the most promising nano-objects at present are the gold nanoparticles. A very convenient and powerful property of these objects is their ability to increase their temperature under electro-magnetic irradiation with certain wavelength. In our research we have directed our efforts toward particular nano-objects specifically sensitive to electromagnetic radiation in the near-infrared region (NIR). In order to study the photothermic properties of the solutions of gold nanoparticles in the NIR we constructed a specific electronic setup consisting of a laser system with interchangeable laser diodes with different wavelength NIR light, a thermally-insulated cuvette-holder compartment with temperature measuring probes and a NIR spectrometer to control the stimulated fluorescence emission of the nanoparticle solutions. The temperature measurement compartment with the thermal-insulated cuvette holder was designed to maintain the solutions’ temperature at a fixed value right before the moment of laser irradiation. To maintain the measurement setup at a fixed temperature before the irradiation we used a thermal stabilized system based on two Peltier cells with electronic temperature control. The temperatures of the ambient air and the temperature of the cuvette walls were continuously measured in order to make corrections about the temperature dissipation during the irradiation.

scholarly journals Optical spectroscopic study of Ru and Rh doped Bi12TiO20 crystals

2019 ◽  
Vol 51 (2) ◽  
pp. 219-223
Author(s):  
P. M. Rafailov ◽  
R. Todorov ◽  
V. Marinova ◽  
D. Z. Dimitrov ◽  
M. M. Gospodinov
Keyword(s):  
Near Infrared ◽  
Infrared Region ◽  
Visible Spectral Range ◽  
Oxidation States ◽  
Vibrational Modes ◽  
Spatially Resolved ◽  
Stretching Vibration ◽  
Growth Method ◽  
Polarized Raman ◽  
Top Seeded Solution Growth

Bi12TiO20 (BTO) single crystals in pristine state and doped with ruthenium and rhodium are grown by the top-seeded solution growth method and characterized by optical and Raman spectroscopy. The effect of doping on the vibrational and optical properties is studied. The doped crystals show higher absorption in the visible spectral range and higher transmission in the near infrared region as compared to pristine BTO. The performed spatially resolved polarized Raman measurements reveal no significant doping-induced shift of vibrational modes while differences in the LO/TO intensity ratio of the tetrahedral asymmetric stretching vibration are encountered. The observations are discussed in terms of lattice ordering and dopant oxidation states.

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