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1.
The aim of this study is to evaluate the biochemical changes in the leaves of wheat seedlings exposed to gold nanoparticles (AuNPs) nondestructively and rapidly using attenuated total reflectance Fourier transform infrared spectroscopy and laser-induced fluorescence. The 18?nm size gold nanoparticles are synthesized by citrate reduction. For analyzing the effect of gold nanoparticles on wheat seedlings, the treatment of gold nanoparticles was applied to the seedlings through roots and following the spectroscopic measurement of biochemical signatures. The laser-induced fluorescence measurement has been performed to access the effect of gold nanoparticles on the chlorophyll concentration of wheat seedlings. The decrease in the fluorescence intensity and the fluorescence intensity ratio on the treatment of gold nanoparticles indicates increase in the concentration of chlorophyll in the leaves of wheat seedlings. The attenuated total reflectance Fourier transform infrarred spectroscopy in combination with principal component analysis has been used to visualize the biochemical changes in the cellulose, hemicellulose, pectin, lignin, amino acids, proteins, and lipid of the leaves of wheat seedlings by recording infrared spectra in the region from 4000 to 400?cm?1. Principal component analysis applied to the preprocessed infrared data clearly distinguishes the spectral variability between control and gold nanoparticle treated seedlings. The study shows that exposure of gold nanoparticles increases the concentrations of cellulose, hemicelluloses, pectin, and lignin in the leaves of wheat seedlings. The increase in these chemicals indicates the modulation of cell walls of the wheat seedlings by the gold nanoparticle treatment. The exposure to gold nanoparticles also enhances the expression of lipid and proteins in the leaves of wheat seedlings.  相似文献   

2.
Sweta Sharma 《Analytical letters》2019,52(10):1629-1652
Widespread commercial application of titanium dioxide nanoparticles leads to their dispersion in the environment and inevitable interaction with living organisms. Their presence necessitates the monitoring of nanoparticle interactions with plants using advanced techniques that are capable of noninvasively and sensitively estimating the changes involved in the biochemical profile. The current study aims to investigate the effects of titanium dioxide nanoparticles on biochemicals of wheat leaves using label free, nondestructive, rapid, sensitive, and advanced spectroscopic probes: laser induced fluorescence and attenuated total reflectance Fourier transform infrared spectroscopy coupled with multivariate analysis. The fluorescence and infrared spectra of control and titanium dioxide nanoparticle treated wheat leaves were acquired in the region from 400 to 800?nm and 4000 to 485?cm?1. The treatment of titanium dioxide nanoparticles decreases the chlorophyll content and the concentrations of cellulose, hemicellulose, xyloglucans, pectin, and lignin indicating interferences in the biosynthesis and structure of cell walls of the wheat leaves. The level of amide I, carbonyl, and methylene groups also increases following the treatment of titanium dioxide nanoparticles indicating lipid and protein peroxidation and the accumulation of carbonyl compounds. The changes in the integrated area ratios of the amide II/amide I, carbonyl/methyl, and methylene/amide II bands demonstrate disorder in the membrane integrity. This study establishes the efficiency of noninvasive, label-free, and rapid protocols based on attenuated total reflectance Fourier transform infrared and laser induced fluorescence to monitor the interactions of nanoparticles with plants at early stage of plant growth before visual signs of toxicity appear.  相似文献   

3.
The goal of the current study is to characterize the changes in the biochemical composition of the leaves of wheat seedlings stressed by arsenic at concentrations of 0.2, 0.3, 0.4, and 0.5?mM using laser induced chlorophyll fluorescence and attenuated total reflectance Fourier transform infrared spectroscopy. The chlorophyll fluorescence spectra of the leaves of control and arsenic treated wheat seedlings showed increase in the intensity and intensity ratios of chlorophyll fluorescence bands indicating decrease in the photosynthesis performance and chlorophyll content of the leaves of wheat seedlings treated with arsenic. The infrared spectra of the leaves of control and arsenic treated wheat seedlings were obtained from 4000 to 485?cm?1 at a resolution of 4?cm?1. Multivariate principle component analysis of the preprocessed spectra suggest significant biochemical discrimination between the control and arsenic treated seedlings. Arsenic treatment decreased the concentration of cellulose while increasing the pectin, hemicellulose, xyloglucan, and lignin levels in the wheat seedling leaves. The exposure to arsenic also increased the spectral signatures of α-helix, β-sheet, amino acids, glutathione, lipids, and carboxyl compounds. These changes in the biochemicals indicate their physiological roles in mediating arsenic stress in wheat seedlings. The study also demonstrates the applicability of spectroscopic techniques for the non-invasive and rapid monitoring of the metabolism and physiology of the vegetation stressed by metals and metalloids before visual signs of toxicity appear.  相似文献   

4.
This study explores the application of spectroscopic techniques (laser induced fluorescence, Raman and attenuated total reflectance Fourier transform infrared) coupled with principal component analysis for the nondestructive, extraction free and rapid evaluation of biochemical changes associated with ripening of chili peppers at four stages (mature, pre-ripe, ripe and post-ripe). The analysis of the fluorescence spectra of the exocarp of chili pepper shows a decrease in the intensity of chlorophyll bands at 685 and 735?nm and an increase in the intensity of carotenoid fluorescence bands at 490–500?nm and 565–580?nm with progress in the ripening stages. These changes are regarded to be significant phenotypic markers for the ripening of chili peppers. The observed changes in the position of carotenoid bands in Raman spectra at 1004, 1156, 1188, and 1524?cm?1 with increase in their intensity indicating the accumulation of carotenoids and change in the carotenoid composition from β-carotene in the mature chilis to capsanthin in the ripe chilis. In addition, the infrared spectra show changes in the carbohydrates, amide II, amide I and cutin at various stages of ripening. Also, the variation in the position of pectin bands indicates change in its molecular mass with decreasing content. The determined spectral signatures can be used as biomolecular index for effective monitoring of the ripening of chili peppers. The commercial application of noninvasive spectroscopic probes will be advantageous for the phenotyping of economically important plant parts, screening, grading, shelf life estimation and quality standardization.  相似文献   

5.
Iron gallates with iron in the oxidation states Fe2+ and Fe3+ were prepared and studied by Mössbauer spectroscopy, X‐ray diffraction, and IR spectroscopy. FeIII 3,4,5‐trihydroxybenzoate (gallate) Fe(C7O5H4) · 2H2O, whose structure was first determined by Wunderlich, was obtained by the reaction of gallic acid and metallic iron or by oxidation of the FeII gallate, which was obtained by the reaction of ferrous sulfate with 3,4,5‐trihydroxybezoic acid (gallic acid) under anoxic conditions. Trials to reproduce the hydrothermal preparation method of Feller and Cheetham show that the result depends crucially on the free gas volume in the reaction vessel. If there is no free volume one obtains the same FeIII gallate as in the other preparation methods. With a large free volume another compound was found to form whose composition and structure could not be determined. It could be specified only by Mössbauer spectroscopy. FeIII gallate, the FeII gallate, and the new phase show magnetic ordering at liquid helium temperature.  相似文献   

6.
本文利用荧光猝灭法、红外光谱法及计算机模拟技术研究了一种聚酰亚胺聚合物(2,6-Bis(4-amino-2-trifluoromethyl phenoxy-4’- benzoyl)-pyridine,简称BAFP )与人免疫球蛋白(HIgG)的相互作用。同步荧光的结果定性地说明了BAFP影响水溶液中HIgG二级结构的情况。而判定BAFP影响HIgG二级结构的定量依据来自红外光谱,实验数据表明α螺旋结构的含量相比未加入药物时增加了约2.6~10.2%,,β折叠增大了约13.6~27.7%,,而β转角则减小了约23.8~30.3%。分子模拟的结果显示BAFP与HIgG的键合作用很强,并且有四个氢键在BAFP与HIgG分子的色氨酸Trp 170, 缬氨酸Val 105, 甲硫氨酸Met 139 及天冬酰胺Asn 52之间形成;同时也显示出维持药物与蛋白质的相互作用力主要是疏水作用,这与实验所得到的热力学参数判定作用力的结果相一致(依据范德霍夫公式计算得 与 的值分别为-6.70KJ.mol-1 和 71.93 J.mol-1.K-1)。  相似文献   

7.
The capacities of Pleurotus ostreatus mushroom and spent substrate were evaluated for the biosorption of cadmium (II) from aqueous solution in order to select the most efficient material for bioremediation. The optimum sorption conditions were optimized, including the pH of the aqueous solution, contact time, biomass dosage, initial metal concentration, and temperature. The sorption of cadmium on both biosorbents was also evaluated by several kinetic, equilibrium, and thermodynamic models. The possible heavy metal biosorption mechanisms were evaluated through point of zero charge (pHpzc), Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDX). Based on the results of column studies, the effectiveness of the P. ostreatus spent substrate was confirmed as a biosorbent for Cd(II) removal from aqueous solutions.  相似文献   

8.
Adsorption technology is widely considered as the most promising and robust method of purifying water at low cost and with high-efficiency. Carbon-based materials have been extensively explored for adsorption applications because of their good chemical stability, structural diversity, low density, and suitability for large scale production. Graphene – a single atomic layer of graphite – is the newest member in the family of carbon allotropes and has emerged as the “celeb” material of the 21st century. Since its discovery in 2004 by Novoselov, Geim and co-workers, graphene has attracted increased attention in a wide range of applications due to its unprecedented electrical, mechanical, thermal, optical and transport properties. Graphene's infinitely high surface-to-volume ratio has resulted in a large number of investigations to study its application as a potential adsorbent for water purification. More recently, other graphene related materials such as graphene oxide, reduced graphene oxide, and few-layered graphene oxide sheets, as well as nanocomposites of graphene materials have also emerged as a promising group of adsorbent for the removal of various environmental pollutants from waste effluents. In this review article, we present a synthesis of the current knowledge available on this broad and versatile family of graphene nanomaterials for removal of dyes, potentially toxic elements, phenolic compounds and other organic chemicals from aquatic systems. The challenges involved in the development of these novel nanoadsorbents for decontamination of wastewaters have also been examined to help identify future directions for this emerging field to continue to grow.  相似文献   

9.
This review is provided a detailed overview of the synthesis, properties and applications of nanoparticles (NPs) exist in different forms. NPs are tiny materials having size ranges from 1 to 100 nm. They can be classified into different classes based on their properties, shapes or sizes. The different groups include fullerenes, metal NPs, ceramic NPs, and polymeric NPs. NPs possess unique physical and chemical properties due to their high surface area and nanoscale size. Their optical properties are reported to be dependent on the size, which imparts different colors due to absorption in the visible region. Their reactivity, toughness and other properties are also dependent on their unique size, shape and structure. Due to these characteristics, they are suitable candidates for various commercial and domestic applications, which include catalysis, imaging, medical applications, energy-based research, and environmental applications. Heavy metal NPs of lead, mercury and tin are reported to be so rigid and stable that their degradation is not easily achievable, which can lead to many environmental toxicities.  相似文献   

10.
During the last years (2000–2014), many publications concerning the forensic analysis of questioned documents have been published, and new techniques and methodologies are nowadays employed to overcome forensic caseworks. This article reviews a comprehensive collection of the works focused on this issue, including dating studies, the analysis of inks from pens and printers, the analysis of paper, the analysis of other samples related to questioned documents and studies on intersecting lines. These sections highlight the most relevant analytical studies by a wide range of analytical techniques. Separation and spectrometric techniques are critically discussed and compared, emphasizing the advantages and disadvantages of each one. Finally, concluding remarks on the research published are included.  相似文献   

11.
In the present paper, a critical overview of the most commonly used techniques for the characterization and the determination of carbon nanotubes (CNTs) is given on the basis of 170 references (2000–2014). The analytical techniques used for CNT characterization (including microscopic and diffraction, spectroscopic, thermal and separation techniques) are classified, described, and illustrated with applied examples. Furthermore, the performance of sampling procedures as well as the available methods for the determination of CNTs in real biological and environmental samples are reviewed and discussed according to their analytical characteristics. In addition, future trends and perspectives in this field of work are critically presented.  相似文献   

12.
Inorganic arsenic (As) displays extreme toxicity and is a class A human carcinogen. It is of interest to both analytical chemists and environmental scientists. Facile and sensitive determination of As and knowledge of the speciation of forms of As in aqueous samples are vitally important. Nearly every nation has relevant official regulations on permissible limits of drinking water As content. The size of the literature on As is therefore formidable. The heart of this review consists of two tables: one is a compilation of principal official documents and major review articles, including the toxicology and chemistry of As. This includes comprehensive official compendia on As speciation, sample treatment, recommended procedures for the determination of As in specific sample matrices with specific analytical instrument(s), procedures for multi-element (including As) speciation and analysis, and prior comprehensive reviews on arsenic analysis. The second table focuses on the recent literature (2005–2013, the coverage for 2013 is incomplete) on As measurement in aqueous matrices. Recent As speciation and analysis methods based on spectrometric and electrochemical methods, inductively coupled plasma-mass spectrometry, neutron activation analysis and biosensors are summarized. We have deliberately excluded atomic optical spectrometric techniques (atomic absorption, atomic fluorescence, inductively coupled plasma-optical emission spectrometry) not because they are not important (in fact the majority of arsenic determinations are possibly carried out by one of these techniques) but because these methods are sufficiently mature and little meaningful innovation has been made beyond what is in the officially prescribed compendia (which are included) and recent reviews are available.  相似文献   

13.
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15.
It is one of the critical fields of green chemistry to catalyze the selective conversion of biomass-derived alcohol and ammonia to primary amines with extensive application. Recently, catalytic systems consisting of non-noble metal nickel- and cobalt-based catalysts have been developed for catalytic alcohol amination. This paper reviewed these two types of catalytic systems, which are classified as skeleton Co and Ni catalytic systems, supported and modified Co and Ni catalytic systems, emphasized on catalysts and catalysis, and clearly explained where zero-valent cobalt or nickel is active species for catalytic reaction. In supported catalysts, the catalytic active sites constituted by the catalytic active species and its micro-environment can regulate the efficiency of catalytic the reaction. While in modified catalysts, modifiers such as metal Fe, Re and Bi may modulate the catalytic active sites and change the catalytic selectivity. There are differences in structure and size between catalysts prepared by different methods, resulting in distinct interface and electronic properties for alcohol amination, which determines the structure–activity relationships of the catalytic system.  相似文献   

16.
This study focuses on the green synthesis of silver and gold nanoparticles using the marine algae extract, Sargassum horneri, as well as the degradation of organic dyes using biosynthesized nanoparticles as catalysts. The phytochemicals of the brown algae Sargassum horneri acted as reducing and capping agents for nanoparticle synthesis. Ultraviolet–visible absorption spectroscopy, dynamic light scattering, high-resolution transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy, X-ray powder diffraction, and Fourier transform infrared spectroscopy were used to characterize the biosynthesized nanoparticles. The green-synthesized SH-AgNPs and SH-AuNPs exhibited high catalytic activity for degradation of organic dyes, such as methylene blue, rhodamine B, and methyl orange. The reduction reactions of dyes are based on pseudo-first-order kinetics.  相似文献   

17.
《Arabian Journal of Chemistry》2020,13(11):8424-8457
Nowadays, increasing extortions regarding environmental problems and energy scarcity have stuck the development and endurance of human society. The issue of inorganic and organic pollutants that exist in water from agricultural, domestic, and industrial activities has directed the development of advanced technologies to address the challenges of water scarcity efficiently. To solve this major issue, various scientists and researchers are looking for novel and effective technologies that can efficiently remove pollutants from wastewater. Nanoscale metal oxide materials have been proposed due to their distinctive size, physical and chemical properties along with promising applications. Cupric Oxide (CuO) is one of the most commonly used benchmark photocatalysts in photodegradation owing to the fact that they are cost-effective, non-toxic, and more efficient in absorption across a significant fraction of solar spectrum. In this review, we have summarized synthetic strategies of CuO fabrication, modification methods with applications for water treatment purposes. Moreover, an elaborative discussion on feasible strategies includes; binary and ternary heterojunction formation, Z-scheme based photocatalytic system, incorporation of rare earth/transition metal ions as dopants, and carbonaceous materials serving as a support system. The mechanistic insight inferring photo-induced charge separation and transfer, the functional reactive radical species involved in a photocatalytic reaction, have been successfully featured and examined. Finally, a conclusive remark regarding current studies and unresolved challenges related to CuO are put forth for future perspectives.  相似文献   

18.
One of the most common problems in wounds is delayed healing and complications such as infection. Therefore, the need for novel materials accelerates the healing of wounds especially abdominal wounds after surgery besides high efficiency and safety is mandatory. The rate of wound healing, anti-inflammatory and biocompatibility of Zn-Al LDH (Zn-Al layer double hydroxide) alone and loaded with Curcumin (Zn-Al LDH/Curcumin) was screened via in-vivo assays through intramuscular implantation in rat abdominal wall with intact peritoneum cavity. The implanted drugs were formed through Curcumin loaded into LDH of Zn-Al with drug release of 56.78 ± 1.51% within 24 h. The synthesized nanocomposite was characterized by (TGA/DTA) thermal analysis, (XRD) X-ray diffraction, (FESEM) Field emission scanning electron microscopy, (HRTEM) high resolution transmission electron microscope, energy dispersive X-ray (EDX) and low-temperature N2 adsorption, pore volume and average pore size distribution. The integrity of blood circulation, inflammatory signs, wound healing rate, capacity of tissue integration, antigenicity and composite biocompatibility, auto fluorescence ability of collagen bundles and the tensile strength of the muscle were assessed histopathologically after 7 and 30 days’ post-implantation. Excellent wound healing ability was achieved with shortest length between the wound gap edges and higher tensile strength of the muscle. Besides emit florescence very well followed by good healing and tensile muscles strength in Curcumin while very low strength with scar formation in Zn-Al LDH/Curcumin in both acute and chronic wound. No signs of inflammation in Curcumin & Zn-Al LDH. No vessels obstruction or bleeding observed in both Zn-Al LDH and Curcumin more than Zn-Al LDH/Curcumin and control which examined through candling. Good healing & infiltrated immune cells in same groups through histopathological examination. This work supports the anti-inflammatory, wound healing and biocompatibility of both LDH and Curcumin with living matter, increasing their biomedical applications in this era with safety and increasing efficacy with prolonged drug release.  相似文献   

19.
《Arabian Journal of Chemistry》2020,13(12):8935-8964
This review depicts the exposure of chitin and chitosan base multifunctional nanomaterial composites for promising applications in field of biomedical science structure, synthesis as well as potential application from a colossal angle. We elaborated critically each of the chitin and chitosan base nanomaterial with its potential application toward biomedical science. For different biomedical applications it use in form of hydrogels, microsphere, nanoparticles, aerogels, microsphere and in form of scaffold. Due to this it had been blended with different polymer such as starch, cellulose, alginate, lipid, hyaluronic acid, polyvinyl alcohol and caboxymethyl cellulose. In this review article, a comprehensive overview of combination of chitin and chitosan base nanomaterial with natural as well as synthetic polymers and their biomedical applications in biomedical field involving drug delivery system all the technical scientific issues have been addressed; highlighting the recent advancements.  相似文献   

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