Optical Properties Of Silver Nanoparticles Research Articles

Paper-based colorimetric nanosensor for detecting halides in aqueous media

The selective detection of halides in aqueous samples is crucial for addressing environmental and physiological concerns. Consequently, the development of an affordable, portable, and user-friendly sensing platform for rapid halide detection holds substantial promise. In this study, we present a novel paper-based nanosensor as an appealing alternative for selectively detecting halides in water. This nanosensor leverages the optical properties of silver nanoparticles (ranging from 50 to 250 nm) embedded in epoxy resin and printed on filter paper. We elucidate the colorimetric behavior of this nanosensor in response to specific halides (chloride, bromide, and iodide) upon contact. Importantly, this sensor discerns, through a single measurement, the presence of these halides in aqueous media with remarkable selectivity. The nanosensor manifests distinct color changes in reaction to different halides, particularly at elevated concentrations (ranging from 2 to 400 mM), surpassing the saturation levels observed in other proposed sensors. These discernible color changes are due to the oxidation of silver nanoparticles, changing their morphology and aggregation density, and can be readily detected and analyzed directly from a captured image. Consequently, it demonstrates considerable potential for integration into automated qualitative monitoring devices based on chromaticity analysis.

Engineering optical properties of silver nanoparticles for broadband absorbing metasurfaces based on a lithography-free process

Constructing ultrafine nanogaps is of crucial importance in realizing significant localized-field enhancement (so called “hot spot”). In this paper, we demonstrated a lithography-free broadband absorbing metasurface consisting of Ag nanoparticles with ultrafine nanogaps fabricated using the laser shock technique incorporated with the thermal-annealing technique. Experimental results and numerical simulations demonstrated that horizontally compressed Ag nanoparticles possessed smaller nanogaps for high sensitivity, uniformity, and stability. Laser shock of metallic nanoparticles showed a strong size effect and pressure dependency. The absorption of the broadband absorbing surfaces reached nearly 94 %, leading to excellent reliability for Raman detection. Furthermore, this novel substrate with different colors exhibited insensitivity to the incident or observation angle in an ambient environment and promising practical applications in many all-angle color filters and biomimetic photonic structures.

Localize surface plasmon resonance of silver nanoparticles using Mie theory

In this work, the optical properties of silver nanoparticles (AgNPs) were explored using Mie theory compared with the experimental AgNPs using the chemical reduction method. Mie’s theory is suited for accurately evaluating the scattering, absorption, and extinction cross-sections of spherical AgNPs. Therefore, the wavelength of localized surface plasmon resonance (LSPR) in the optical spectra of the spherical AgNPs was calculated. The experimental AgNPs have a spherical shape with an average particle size of 30 nm. In addition, the crystalline structure of AgNPs was found to be cubic with fcc structure with lattice constant a= 4.155 Å. Moreover, the excitation of the LSPR of the AgNPs was simulated using the finite-difference time-domain (FDTD) method at different wavelengths to explore the LSPR phenomena. The results show that spherical AgNPs are the most widely used materials in biosensors, biomedicine, optoelectronic devices, and solar cells due to their surface plasmon resonances in the visible spectrum region.

Study of the Optical Properties of Silver Nanoparticles Prepared by the Pulsed Laser Ablation Technique in Water

Pulsed laser ablation technique (neodymium Yak pulsed laser) was used to prepare silver nanoparticles from silver sheet target with purity (99.99%) different laser wavelengths (532nm,1064nm, 1320nm) and different energies(600mj,800mj ,1000mj) were used in the preparation .The laser frequency was (6Hz) and the number of pulse was 1000 pulse. The optical properties of the nanoparticles were studied with UV-VISIBLE spectroscopy. The absorption spectra showed the appearance of sharp peaks as a result of surface Plasmon resonance at different wavelengths, these peaks appeared at wavelengths (400nm) for lasers with wavelength (532nm) and different energies ,while peaks appeared at wavelengths (400nm) for lasers with wavelength (1064nm) ,and finally wavelength at which peaks appeared was (409nm) for lasers with wavelength (1320nm).

Concentration dependence of NaBH4 reductant on the optical properties of colloidal silver nanoparticles synthesized from AgNO3 solution

Synthesis of silver nanoparticles was successfully synthesized by a chemical reduction method using silver nitrate (AgNO3) as a precursor and sodium borohydride (NaBH4) as a reducing agent. The optical properties of silver nanoparticles were studied based on their surface plasmon resonance (SPR) phenomenon using UV-Visible spectrophotometry. The absorbance spectra of colloidal silver nanoparticles show the peak at the wavelength range of 380 nm to 450 nm. Colloidal silver nanoparticles have good stability after storage at room temperature.

Optical Characteristics of Silver Nanoparticles Obtained Using Artemisia tilesii Ledeb. "Hairy" Root Extracts With High Flavonoid Content

Background. "Hairy" roots can be used for production of plant-derived secondary metabolites, such as flavonoids, which have antioxidant and reducing properties. It seems promising to use the process of silver nanoparticles formation as a method of determining the level of reducing power. This approach allows simul­taneously to obtain nanoparticles with different biological activity and evaluate the reducing potential of dif­ferent plants. Objective. The aim of the study was to determine the dependence of optical properties (ultraviolet/visible spectroscopy, UV-Vis spectra) of solutions of silver nanoparticles obtained using wormwood "hairy" root extracts on the content of flavonoids as compounds with reducing activity. Methods. Four Artemisia tilesii “hairy” root lines from the collection of the Institute of Cell Biology and Genetic Engineering NAS of Ukraine were grown for five weeks in liquid 1/2 MS medium with 20 g/l sucrose. "Hairy" roots were homogenized in 70% ethanol, the extracts were centrifuged, total flavonoid content was determined, and extracts were used for the silver nanoparticles preparation via reduction of Ag+ to Ag0 from AgNO3. UV-Vis spectra at 300–600 nm range were recorded right after colloid solution preparation, in five, and in nine days. Results. Total flavonoid content varied from 4.01 ± 0.39 to 15.37 ± 1.08 mg RE/g FW. The UV-Vis spectra curves of absorption increased with the course of time, mostly from day 0 to day 5. At this period, absorption at 370–500 nm wavelength increased almost twofold. The peak absorption of all samples was detected at 440 nm, and the maximum values at the wavelength of 440 nm correlated with the content of flavonoids. This correlation did not change over time. Conclusions. The optical properties of silver nanoparticles colloid solutions obtained using A. tilesii "hairy" root extracts correlated with the total flavonoid content of the samples. Even though the absorbance of the colloid solutions increased with time, those increases correlated with flavonoid content as well. The determination of the optical properties of AgNPs colloid solution can be used as a convenient way of quickly comparing the reducing ability of extracts both right after the formation of a colloidal solution and after some time of its storage.

Excitation Wavelength and Colloids Concentration-Dependent Nonlinear Optical Properties of Silver Nanoparticles Synthesized by Laser Ablation.

We reported experimental results from investigations that employed the Z-scan method to explore the dependence of silver nanoparticles’ (AgNPs) nonlinear optical properties on the excitation wavelength, AgNP concentration, and size. Using a 532 nm Nd: YAG laser beam at 100 mJ/pulse for different ablation times, AgNPs were synthesized from a silver target immersed in distilled water. UV–Vis spectroscopy and an atomic absorption spectrometer are used to characterize the optical properties of laser-synthesized AgNPs as well as their concentrations. The AgNPs’ size and shape are determined using a transmission electron microscope (TEM). The laser-synthesized AgNPs are spherical, with an average particle size of 12 to 13.2 nm. Whatever the ablation time, the AgNP colloids exhibit reversed saturable absorption and a negative nonlinear refractive index (n2). Both n2 and the nonlinear absorption coefficient (α3) increase as the AgNP concentration increases. As the excitation wavelength and average size of the AgNPs increase, n2 and α3 decrease.

Nonlinear Optical Properties of Silver Nanoparticles Produced by Laser Ablation

Nonlinear Optical Properties of Silver Nanoparticles Produced by Laser Ablation

Optical limiting and nonlinear optical properties of silver nanoparticles embedded glasses containing rare-earth ions at 532 nm under nanosecond regime

Optical limiting and nonlinear optical properties of silver nanoparticles embedded glasses containing rare-earth ions at 532 nm under nanosecond regime

Using femtosecond laser pulses to investigate the nonlinear optical properties of silver nanoparticles colloids in distilled water synthesized by laser ablation

The nonlinear optical properties of silver nanoparticles (AgNPs) colloids in distilled water, when irradiated with 100 fs laser pulses, were investigated experimentally using the Z-scan technique. At a constant wavelength of 760 nm and different excitation powers, the nonlinear absorption coefficient and nonlinear refractive index were measured. The AgNPs colloids are synthesized by laser ablation of silver bulk in distilled water using a 532 nm Nd: YAG laser with different ablation energies fluence of 9, 15.5, and 26 ⨯104 (J/cm2) over a 30min ablation time. The nanoparticle size, shape, and absorption spectra of nanoparticle colloids were determined using transmission electron microscopy and an ultraviolet–visible spectrophotometer. Spherical AgNPs are formed with an average diameter ranging from 7.5 to 12 nm. As the laser ablation energy fluence increases, the average size of the AgNPs decreases while the bandgap energy increases. As the excitation laser power and AgNPs size increase, the nonlinear absorption coefficient and nonlinear refractive index decrease. The optical limiting performance of AgNPs improves with increasing laser ablation energy fluence, with the best performance at 26⨯104 (J/cm2).

Optical properties of silver nanoparticles based on their structural defects

The relation between the defects in island silver films produced by thermal spraying and their optical properties has been studied. The effect of defects in nanoparticles on the photo effect has been studied. Radiation with a wavelength of 355 nm (quantum energy 3.5 eV) causes a single-photon photo effect, while the work function of bulk silver is not lower than 4.2 eV. A hypothesis was put forward about the relation between defects in nanoparticles and their absorption spectra. In the process of deposition an absorption peak appears on the extinction spectra of a silver island film at a wavelength of 370 nm, which disappears within several tens of minutes after the end of deposition. It was also shown, that the defects in islands can be created artificially by irradiating them with ultraviolet light, that leads to an increase in the rate of self-diffusion in these islands upon heating. Key words: nanoparticles, defects, diffusion, extinction spectra.

Preparation and study of the structural and optical properties of silver nanoparticles prepared from extracts of some plants

The study included the preparation of silver nanoparticals using Punica granatum extract . as silver nanoparticals were prepared by biological method . which is one of the best ways for its cheapness and the fact that is does not require time and does not leave toxic substance .in the study , the active compounds of the extract were detected and some physical properties of AgNps were studied . the optical and structural properties of the prepared nanoparticles were studied by Uv-Visible spectrophoto meter measurement. perform an infrared spectrophotometric test (FTIR ) a filed – emitting scanning electron microscope was also performed , ( EDX ) , ( X-RAY ) and the results of ( FESEM ) measurement showed that silver nanoparticles are of oval shape , and of different sizes ranging from ( 32.55 -70.55 ) nm . with a rate of (45.98) nm . Keywords: Punica granatum plant , silver nitrate , ethanol alcohol . DOI: 10.7176/APTA/85-03 Publication date: December 30 th 2021

Experimental implementation of Raman scattering spectroscopy, photoluminescence and some optical properties of silver nanoparticles created by eco-friendly technique

The object of research is studying Raman scattering technique, photoluminescence and some optical properties of silver nanoparticles created by eco-friendly technique which independent on a long time, effort, energy and high temperatures, and with the highest adsorption capacity in order to achieve a high inhibition to paralyze the activity of the bacterial wall, by achieving the highest surface plasmon resonance (SRR). Silver nanoparticles were prepared using Matricaria Flower extract. Characterization of silver nanoparticles and detection of their effectiveness against microbial using two types of bacteria (Escherichia Coli and Staphylococcus aureus ), these nanoparticles were measured using a number of measurements, X-ray diffraction measurement, Energy Dispersion (EDX), (FESEM), U–V Spectroscopy, Fourier Transform Infrared (FTIR), Photoluminescence (PL) properties of silver nanoparticle at room temperature and Raman scattering spectroscopy were investigated. The Scherrer’s equation was used to calculate the crystallite size of Silver nanoparticles, the average crystallite size is 48.64 nm. The PL spectra of silver nanoparticles exhibit two emission bands: one is in the UV region 350 nm and the other is in the visible region 650 nm. This is roughly identical to the absorption spectrum results. The antimicrobial activity was tested against gram negative bacteria (Escherichia coli) and gram positive bacteria (Staphylococcus aureus). Prepared Ag NPs exhibited inhibitory activity in both types of bacteria strains at best selectivity against gram-negative bacteria.
 An eco-friendly technique is used for synthesizing technique to produce silver nanoparticles with the expected best application properties. These research results suitable to be use the Silver nanoparticles in sensors and many electronic, electrical, medical and biological applications

Optical properties of silver nanoparticles upon exposure to bacteria

Changes in localized surface plasmon resonance due to bacterial interaction have been overlooked but have important applications for pathogen detectors.

Recent Advances in (Bio)Chemical Sensors for Food Safety and Quality Based on Silver Nanomaterials.

SUMMARYThere is a continuing need for tools and devices which can simplify, quicken and reduce the cost of analyses of food safety and quality. Chemical sensors and biosensors are increasingly being developed for this purpose, reaping from the opportunities provided by nanotechnology. Due to the distinct electrical and optical properties of silver nanoparticles (AgNPs), this material plays a vital role in (bio)sensor development. This review is an analysis of chemical sensors and biosensors based on silver nanoparticles with application in food and beverage matrices. It consists of academic research published from 2015 to 2020. The paper is structured to separately explore the designs of two major (bio)sensor classes: electrochemical (including voltammetric and impedimetric sensors) and optical sensors (including colourimetric and luminescent), with special focus on the type of silver nanomaterial and its role in the sensor system. The review indicates that diverse nanosensors have been developed, capable of detecting analytes such as pesticides, mycotoxins, fertilisers, microorganisms, heavy metals, and various additives with exceptional analytical performance. Current trends in the design of such sensors are highlighted and challenges which need to be overcome in the future are discussed.

High-sensitivity Hg2+ sensor based on the optical properties of silver nanoparticles synthesized with aqueous leaf extract of Mimusops coriacea

In the presented manuscript, spherical silver nanoparticles (AgNPs) which were prepared via green chemical method in a single step take only a few minutes to be ready as a Hg2+ ions detector based on the plasmon band changes. The AgNPs were obtained with the aqueous extract of Mimusops coriacea leaves. The components of the extract as tannins and polyphenolic compounds were responsible for the reduction in metal ions and the particles encapsulation. The AgNPs were characterized by UV–Vis spectroscopy, fluorescence, Fourier transform infrared, dynamic light scattering analysis and transmission electron microscopy. The AgNps presented an average diameter of 15 nm and a zeta potential value of ~ − 28 mV. They were monodispersed and stable for up to 180 days. AgNPs are used as a Hg2+ sensor with high sensitivity and selectivity. The fast, simple and low-cost method is based on changes in the AgNP surface plasmon resonance band (λ ≈ 410 nm) with LOD 6.5 ng/mL (32.5 nM), without functionalization of the AgNPs. The low LOD demonstrates its potential for Hg2+ quantification in environmental samples such as fish, soil, and effluent discharge.

The Influence of Size and Chemical Composition of Silver and Gold Nanoparticles on in vivo Toxicity with Potential Applications to Central Nervous System Diseases.

The physicochemical and optical properties of silver nanoparticles (SNPs) and gold nanoparticles (GNPs) have allowed them to be employed for various biomedical applications, including delivery, therapy, imaging, and as theranostic agents. However, since they are foreign body systems, they are usually redistributed and accumulated in some vital organs, which can produce toxic effects; therefore, this a crucial issue that should be considered for potential clinical trials. This review aimed to summarize the reports from the past ten years that have used SNPs and GNPs for in vivo studies on the diagnosis and treatment of brain diseases and those related to the central nervous system, emphasizing their toxicity as a crucial topic address. The article focuses on the effect of the nanoparticle´s size and chemical composition as relevant parameters for in vivo toxicity. At the beginning of this review, the general toxicity and distribution studies are discussed separately for SNPs and GNPs. Subsequently, this manuscript analyzes the principal applications of both kinds of nanoparticles for glioma, neurodegenerative, and other brain diseases, and discusses the advances in clinical trials. Finally, we analyze research prospects towards clinical applications for both types of metallic nanoparticles.

The nonlinear optical properties of silver nanoparticles decorated glass obtained from sintering mesoporous powders

ABSTRACTSilver nanoparticles (Ag NPs) have excellent third‐order nonlinear optical properties but it is still difficult to obtain silica glass containing Ag NPs with homogenous dispersion and small particle size. Herein, silica glass with homogenously distributed Ag NPs in its matrix was derived from sintering a famous type of mesoporous silica (FDU‐12) encapsulated with Ag NPs (Ag NPs/FDU‐12) through Spark Plasma Sintering (SPS) technique. Benefited from the low‐temperature sintering property of the Ag NPs/FDU‐12 powders (~930°C within 5 min), the Ag NPs can be directly trapped in the derived silica glass with small particle size (<3.0 nm) and without mass loss. The as‐prepared Ag NPs/glass showed a typical reverse saturable absorption curve, which is measured via the Z‐scan method by using a 532 nm nanosecond laser. The nonlinear coefficient and imaginary third‐order susceptibility were calculated as 11.46 cm/GW and 2.22 × 10−12 esu, respectively, indicating the excellent third‐order nonlinear optical properties of the Ag NPs/glass. This study demonstrates a great potential for preparing silica glasses functionalized with well dispersed ultrafine functional particles, which is appealing in photonic field.

Plasmon enhanced linear and nonlinear optical properties of natural curcumin dye with silver nanoparticles

The interactions between silver nanoparticles and bio molecules have potential significance in many interesting applications like sensing, imaging etc. In the present work, the variation in the fluorescence emission and nonlinear optical response of natural Curcumin dye extracted from the Curcuma longa with laser synthesized silver nanoparticles was studied. The formation and optical properties of silver nanoparticles and Curcumin dye solutions were analyzed using UV–Visible absorption spectroscopy, fluorescence emission spectroscopy and fluorescence life time studies. The third order nonlinear optical behavior of the Curcumin dye samples with incorporation of varying concentration of silver nanoparticles were investigated using open aperture Z-scan method. A substantial enhancement was observed for the entire optical behavior such as non-linear optical response, optical limiting properties and fluorescence emission of the Curcumin samples with silver nanoparticles, which progressively improved with the concentration of the silver nanoparticles incorporated into the system.

Structural and Optical Properties of Silver Nanoparticles In Situ Synthesized in ZnO Film by Sol–Gel Method

We fabricate the samples with two layers of silver nanoparticles embedded in ZnO film exploring sol–gel method by varying the annealing temperatures. The structural properties of the samples are determined by transmission electron microscopy. The effect of the annealing temperature on the nanoparticles plasmon absorption spectra is studied. Annealing at 570 °C results in a shift of the plasmon absorption maximum from 580 nm to 620 nm, due to an increase in the nanoparticles average size from 63 nm to 74 nm. Increasing the annealing temperature to 650 °C results in a shift of plasmon absorption maximum back to 580 nm due to a decrease in the nanoparticles size to 61 nm. Before annealing, the silver nanoparticles of the upper layer locate on top of the nanoparticles of the bottom layer, however, in the plane of the layers, they are arranged randomly at a distance of 30 to 150 nm from each other. As a result of the annealing, the system tended to be ordered, as a result, the nanoparticles in the layers become to be distributed equidistant at 40–70 nm between them; the nanoparticles of the upper layer tend being located between the nanoparticles of the bottom layer.