Sharif Digital Repository

In today's era, metal nanoparticles play an important role in technologies emerging from different sciences, such as chemistry, physics, optics, material science, due to their unique characteristics. In the development of nanooptics science, it can be said that metal nanoparticles play an important role. The ability of conductive electrons collective oscillation causes surface charge density fluctuations in nanoparticles, this phenomenon is known as surface plasmons. Surface plasmons are surprisingly coupled with light and cause the significant increase in the intensity of optical fields induced in nanoparticles. Therefore, with the presence of localized surface plasmons or plasmon... 

Due to the widespread use of pesticides and their harmful effects on humans and wildlife, monitoring their residual amounts in crops is critically essential but still challenging regarding the development of high-throughput approaches. Herein, a colorimetric sensor array has been proposed for discrimination and identification of triazole fungicides using monometallic and bimetallic silver and gold nanoparticles. Aggregation-induced behavior of AgNPs, AuNPs and Au-AgNPs in the presence of four triazole fungicides produced a fingerprint response pattern for each analyte. Pattern recognition methods, including linear discriminant analysis (LDA) and hierarchical cluster analysis, have been... 

In this research binuclear platinum(IV) complexes with coinage metals have been synthesized and characterized. the trimethyl platinum(IV) complex [PtMe3(phthalazine)3]+X- has been prepared by the reaction of [PtMe3(THF)]4 with 3 equiv. phthalazine and used as initial material. The first complex, [PtMe3(µ-(phthalazine)2Cl)PtMe3], synthesized via reaction of 2 equiv. [Pt(Me)3(Phthalazine)3] with 1 equiv. [AuClSMe2]. The second complex, [PtMe3(µ-phthalazine)3Ag][BF4], synthesized by reaction of one equiv. of each compound [Ag(CH3CN)4]BF4 and [Pt(Me)3(Phthalazine)3] And the third complex, [PtMe3(µ-phthalazine)3Cu][PF6], synthesized like second one via reaction of [Cu(CH3CN)4]PF6 and... 

Silver(I) complex of [Ag2(μ-dppm)2(μ-phth)(phth)](BF4)2 (1) (dppm = bis(diphenylphosphino)methane and phth = phthalazine) has been prepared from the reaction of [Ag(CH3CN)4]BF4 with phthalazine and dppm in a 1:1 molar ratio. The structure of 1 was determined using X-ray crystallography in solid state and by multinuclear NMR spectroscopy in solution. Complex 1 shows a dynamic process including rotation of phthalazine ligand around the [Ag2(μ-dppm)2] unit wich was investigated by 1H NMR, 31P NMR and 13C NMR spectroscopy. Also, the complex 1 shows the aggregation induced emission (AIE) probably by restriction of internal motions (RIM). The trimethyl platinum(IV) complex [PtMe3(phth)3]+X- (2)... 

Development of simple and rapid approaches for identification of pesticides has been known as a critical demand, due to the broad usage of pesticides and their harmful effects on mammals. Herein, we have introduced a silver nanoparticle (AgNP) based colorimetric sensor array for simultaneous identification of Azinphosmethyl (AM) and Phosalone (PS). In the presence of the target pesticides, unmodified AgNPs at various pHs (4.5, 5.5 and 9.5) showed different aggregation behaviours. As a result of aggregation, the color and UV-Vis spectra of AgNPs changed which led to distinct patterns for AM and PS. The aggregation induced spectral changes of AgNPs were used to identify AM and PS with the help... 

There is a growing interest in developing high-performance sensors monitoring organophosphate pesticides, primarily due to their broad usage and harmful effects on mammals. In the first part of this research, by introducing conditional sensor elements (CSE), a colorimetric sensor array has been proposed for the detection and discrimination of several organophosphate pesticides (OPs). citrate-capped 13 nm gold nanoparticles (AuNPs) at nine different pH/ionic strengths were employed as simple plasmonic sensing elements in the development of a colorimetric sensor array for the detection and discrimination of five organophosphate pesticides, including azinphos-methyl (AM), chlorpyrifos (CP),... 

In this project, the catalytic properties of CuO and ZnO were investigated in reduction reactions.MOFs were used as a precursor to preparation of these metal oxides. Gold and silver nanoparticles were used to improve the catalytic properties of the prepared metal oxides. Structural characteristics of nanocatalysts were stydied by SEM, TEM, XRD and FT-IR techniques. The prepared nanocomposites were applied in the catalytic reduction of paranitrophenol in the presence of sodium borohydride and the kinetics and mechanism were investigated according to the structure of the prepared catalysts  

There is a growing interest in developing high-performance sensors monitoring fungicides, due to their broadly usage and their adverse effects on humans and wildlife. In the present study, a colorimetric probe has been proposed for detection of prothioconazole based on aggregation of unmodified silver nanoparticles (AgNPs). Under optimized condition, linear relationships between the concentration of prothioconazole and the absorbance ratio of A500/A395 were found over the range of 0.01 µg. mL-1 to 0.4 µg. mL-1 with Detection limit as low as 1.7 ng. mL-1. Furthermore, AgNPs color change from yellow to pink-orange in presence of prothioconazole, indicates highly sensitive naked-eye... 

Nowadays, electrochemical sensors have numerous benefits, including simplicity,low cost, high selectivity and high sensitivity as an efficient and useful tool in various fields such as the environment, disease diagnostics, medical and medical surveillance, and Anti-terrorism security systems have become the focus of attention in the field of analytical measurements. In the meantime, carbon nanostructures and metal nanoparticles have been considered as suitable alternatives in order to improve their surface properties due to their unique electronic properties and mechanical and chemical stability. Since the determination of trace amounts of pharmaceutical and biological compounds is very... 

Pesticides are broadly applied in croplands, glasshouses, and orchards in order to increase agricultural products and their quality. Among the variety of pesticides, organophosphorus pesticides (OPs), possessing high insecticidal activity, acute toxicity and relatively short environmental persistence, have been widely used for pest control in agriculture. However, this effect might lead to adverse health impacts or death for mammals and humans. Thus, even at trace levels, it is of great importance to develop a simple, sensitive, inexpensive and real-time detection method for monitoring the levels of pesticides in the environment, foodstuffs and biological samples. The integration of metallic... 

In this thesis the graphene-based magnetic nanocatalyst was synthesized. The surface of this catalyst was cavered by silica and AgNPs. In addithion of simple sepration by magnetbar, yeild of reaction was promoted by surface modification. Catalyst structure was verified by transmission electron microscopy , scanning electron microscope, fourier transform infrared spectroscopy, X-ray diffraction and Energy dispersive spectroscopy.At the end catalytic activity was examined by oxidation reaction in persense of different alcohols. The oxidation of benzylic alcohol with electron withdrawing substituents was more difficult and the yield was lower, but electron donor substituents effect positively... 

This thesis deals with the synthesis and characterization of some nanostructured conductive polymers and their applications toward microextraction of drugs, environmental pollutants and pesticides from aqueous and biological samples. In chapters 3–6, silver nanoparticles and their relevant nanocomposites were applied as the desired extracting media while in the last chapter, a polyaniline nanocomposite, containing titanium oxide nanoparticles, was synthesized and employed as an efficient medium for the extraction purposes. In the first work, a nanocomposite based on polyaniline-silver nanoparticles (PANI-Ag NPs) was synthesized and used as an extraction medium for microextraction in packed... 

In the first work, a stable composite film of silver nanoparticles decorated on reduced graphene oxide is easily prepared. The surface morphology of the modified electrode is characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. The electrochemical behavior of TNZ on the surface of the modified electrode is investigated by using linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). The prepared modified electrode acts as a highly sensitive platform for the voltammetric determination of tinidazole (TNZ). Voltammetric investigations demonstrated that, in comparison to the glassy carbon electrode individually coated with... 

The increasing utilization of silver nanoparticles (Ag-NPs) in industrial and consumer products has raised concern to wastewater treatment utilities, due to its antimicrobial activity. In this research, recovery of silver nanoparticles from wastewater via using activated carbon and convert it into usable nanoparticles is presented. real waste of silver nanoparticles have been used and activated carbon as adsorbent has a high absorption recovery for silver. Under the optimized experimental parameters e.g. pH, temperature, time of process, and amount of activated carbon, an absorption maximum was achieved and over than 99% of silver nanoparticles can be removed from wastewater. After the... 

Multivariate calibration methods are used for simultaneous determination of two or more different species in the mixture of species. If the responses of species are similar, multivariate calibration has the ability of modeling the relation between responses and species concentration, too. Artificial neural networks, using as more applicable methods of nonlinear multivariate calibrations, when the relation is nonlinear, In the first part, lisinopril and arginine are simultaneously determined by artificial neural network. Separate calibration curves are obtained for lisinopril and arginine. Then spectra of reaction product of 38 different mixtures of two species with... 

In the first part, metallic nanoparticles were synthesized on the different carbon nanostructers platform such as nanodiamond and graphene sheet using electrochemical and chemical methods. The prepared composite film were characterized by electron microscopy, spectroscopy and electrochemical techniques. The synthesized nanocomposite were applied as a modifier in order to prepare electrochemical sensors for determination trace amount of important pharmaceutical and biological compounds.In the first work, Nanodiamond-graphite (NDG) decorated with Ag nanoparticles (AgNPs-NDG) was synthesized with chemical method. The surface morphology and the nature of the composite were investigated. The... 

Antibacterial coatings are a branch of paints and coatings industry that has a wide application from Clothing and Textiles to Floor and Medical instrument. Different antibacterial agents such as silver, titanium dioxide, zinc oxide, gold, chitosan, Silicon dioxide, Magnesium hydroxide and carbon nanotubes have been used. UV curable coatings are economic and environmentally friendly coatings and they are one of the fastest growing segments in the paint and coatings industry. Many studies have been conducted on UV curable coatings and their properties. Among different resins, The UV curable polyurethane offer properties such as: Excellent hardness, High gloss, good chemical and weather... 

In this work two shapes of silver nanostructures including silver nanowires and silver nanocubeswere synthesized by polyol method. Silver nanostructures were characterized by SEM, XRD and UV-Vis spectroscopy. Afterwards the morphology-dependent electrocatalyticperformance of these nanocrystals on the differential pulse behavior of naltrexone (NAL) was investigated. To this aim the differential pulse voltammetric behavior of NAL on a glassy carbon electrode modified with electrochemical deposited gold nanoparticles conjugated with different shapes of silver nanostructures and nafion was investigated. It was proved that silver nanowires show more effective electrocatalytic activity toward... 

Silver nanoparticles (Ag-NPs) are promising agents in bionanotechnology, because of their unique activity against unfavorable processes in bioscience such as undesirable microbial growth, angiogenesis in tumors and etc. Ag-NPs have been widely used in wound dressing; wound healing, water treatment filters, inks, sensors, catalysts, cosmetics, orthopaedics, surgical instruments and vascular prosthesis. Ever-increasing applications of Ag-NPs in biomedical field are due to the anti-bacterial, anti-fungal, anti-viral, anti-platelet, anti-proliferative, anti-inflammatory (apoptosis detection) and anti-angiogenesis properties (cancer therapy). In the current research, we synthesized Ag-NPs in... 

Aspect ratio dependant optical properties of silver and gold nanorods is responsible for great attention toward controlling the aspect ratio of this class of the nanostructure for their application in variety of area, such as medical diagnosis, drug delivery, biosensing and treatment. In this research, gold and silver nanorods have been synthesized using chemical reducation and growth based on seed mediated method, which is the newest and one of the best methods with less difficulty for producing silver and gold nanorods. Absorption of the visible light by gold and silver nanorods results in appearing the longitudinal and transverse Plasmon bands in their absorption spectra which is related...