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Showing papers by "Thalappil Pradeep published in 2016"


Journal ArticleDOI
TL;DR: Results indicate that ZnO-nanoparticulates have significant effects on growth, yield, and zinc content of maize grains, which is an important feature in terms of human health.
Abstract: In the present investigation, nanoscale zinc oxide particulates (ZnO-nanoparticulates) were prepared using a modified oxalate decomposition method. Prepared ZnO-nanoparticulates (mean size = 25 nm) were characterized using techniques such as transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and zeta potential analyzer. Different concentrations (50, 100, 200, 400, 600, 800, 1000, 1500, and 2000 ppm) of ZnO-nanoparticulates were examined to reveal their effects on maize crop on overall growth and translocation of zinc along with bulk ZnSO4 and control. Highest germination percentage (80%) and seedling vigor index (1923.20) were observed at 1500 ppm of ZnO-nanoparticulates. The yield was 42% more compared to control and 15% higher compared to 2000 ppm of ZnSO4. Higher accumulation of zinc (35.96 ppm) in grains was recorded with application of 100 ppm followed by 400 ppm (31.05 ppm) of ZnO-nanoparticulates. These results indicate that ZnO-nanoparticulates have significan...

170 citations


Journal ArticleDOI
TL;DR: The first example of intercluster reactions between atomically precise, monolayer protected noble metal clusters using Au25( SR)18 and Ag44(SR)30 (RS- = alkyl/aryl thiolate) as model compounds is presented.
Abstract: We present the first example of intercluster reactions between atomically precise, monolayer protected noble metal clusters using Au25(SR)18 and Ag44(SR)30 (RS- = alkyl/aryl thiolate) as model compounds. These clusters undergo spontaneous reaction in solution at ambient conditions. Mass spectrometric measurements both by electrospray ionization and matrix assisted laser desorption ionization show that the reaction occurs through the exchange of metal atoms and protecting ligands of the clusters. Intercluster alloying is demonstrated to be a much more facile method for heteroatom doping into Au25(SR)18, as observed by doping up to 20 Ag atoms. We investigated the thermodynamic feasibility of the reaction using DFT calculations and a tentative mechanism has been presented. Metal core-thiolate interfaces in these clusters play a crucial role in inducing these reactions and also affect rates of these reactions. We hope that our work will help accelerate activities in this area to establish chemistry of monolayer protected clusters.

144 citations


Journal ArticleDOI
01 Apr 2016-Carbon
TL;DR: In this article, the preparation of a carbon aerogel (CA) material utilizing the simultaneous co-assembly of organic and inorganic precursors, having a high Brunauer-Emmet-Teller surface area of 2600 m2/g, through a one-step sol-gel process was reported.

131 citations


Journal ArticleDOI
TL;DR: It is demonstrated that a mixture of Ag25( SR)18 and Au25(SR)18 can be transformed to any arbitrary alloy composition, AgmAun(SR), merely by controlling the reactant compositions, and confirmed that metal atom exchanges are thermodynamically feasible.
Abstract: Ambient, structure- and topology-preserving chemical reactions between two archetypal nanoparticles, Ag25(SR)18 and Au25(SR)18, are presented. Despite their geometric robustness and electronic stability, reactions between them in solution produce alloys, AgmAun(SR)18 (m+n=25), keeping their M25(SR)18 composition, structure and topology intact. We demonstrate that a mixture of Ag25(SR)18 and Au25(SR)18 can be transformed to any arbitrary alloy composition, AgmAun(SR)18 (n=1-24), merely by controlling the reactant compositions. We capture one of the earliest events of the process, namely the formation of the dianionic adduct, (Ag25Au25(SR)36)2-, by electrospray ionization mass spectrometry. Molecular docking simulations and density functional theory (DFT) calculations also suggest that metal atom exchanges occur through the formation of an adduct between the two clusters. DFT calculations further confirm that metal atom exchanges are thermodynamically feasible. Such isomorphous transformations between nanoparticles imply that microscopic pieces of matter can be transformed completely to chemically different entities, preserving their structures, at least in the nanometric regime.

101 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of 2D reduced graphene oxide (rGO) sheets on the properties of Portland cement paste in comparison to popularly reviewed nanomaterials like aluminium oxide nanopowder (n-Al2O3) and colloidal silicon dioxide nanoparticles (n -SiO2) were investigated.
Abstract: In this experimental study, the effects of 2D reduced graphene oxide (rGO) sheets on the properties of Portland cement paste in comparison to popularly reviewed nanomaterials like aluminium oxide nanopowder (n-Al2O3) and colloidal silicon dioxide nanoparticles (n-SiO2) were investigated. The addition of 0.02% rGO sheets by weight of cement increased the 7 and 28 days flexural strength up to 70% and 23% respectively when compared to control paste. Moreover, its incorporation substantially decreased the sizes of pores/voids in the paste, even compared to the other nanomaterials, as characterized by Mercury Intrusion Porosimetry (MIP) and 3D X-ray Computed Tomography (CT) aided with image analysis technique. The assessment of Portlandite content by Thermo-gravimetric Analysis did not indicate major differences between the pastes, with the exception of the paste incorporating nano-silica. Microstructural analysis by Fourier Transform Infrared Spectroscopy, X-ray diffraction and Scanning Electron Microscopy did not reveal any major differences between the control paste and the pastes incorporating nanomaterials. The overall results suggest that the performance of rGO was better in comparison to other two nanomaterials, despite the significantly lower amounts that were used in the paste.

78 citations


Journal ArticleDOI
TL;DR: The composite showed unusual adsorption capacity, as high as 1534 mg/g, which facilitated the complete removal of the pollutants and makes the composite an excellent substrate for purification of water.

59 citations


Journal ArticleDOI
TL;DR: In this paper, a luminescent atomically precise cluster-cellulose nanocrystal composite, namely, bovine serum albumin-protected gold nanoclusters (Au@BSA NCs)-loaded cellulose nan-ocrystal-alginate hydrogel beads, that can simultaneously sense and scavenge heavy metal ions, specifically mercury ions in water.
Abstract: Development of a system that can simultaneously sense and scavenge toxic heavy metal ions at low concentrations is an ideal solution for in situ monitoring and purification of contaminated water. In this paper, we report on the synthesis and application of a novel system, luminescent atomically precise cluster–cellulose nanocrystal composite, namely, bovine serum albumin-protected gold nanoclusters (Au@BSA NCs)-loaded cellulose nanocrystal–alginate hydrogel beads, that can simultaneously sense and scavenge heavy metal ions, specifically mercury ions in water. Characterization of the system performed using scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray photoelectron spectroscopy elucidated the physical and chemical characteristics of the system. Additionally, we proposed a new method to visualize the diffusion phenomenon and calculate the effective diffusion coefficient of heavy metal ions in hydrogel beads by monitoring the fluorescence-quenching dynamics of Au@BSA NCs ...

58 citations


Journal ArticleDOI
TL;DR: The first example of dimer formation in the monolayer protected atomically precise cluster system, Au25(SR)18, is presented, using ion mobility mass spectrometry.

50 citations


Journal ArticleDOI
TL;DR: It is revealed that white and brown regions start forming within the nut when the liquid within starts solidifying, and the transport of molecules with maturity and corresponding pattern formation are expected to be associated with a multitude of physiochemical changes.

41 citations


Journal ArticleDOI
TL;DR: Two different isomers of Ag11(SG)7(-) with different drift times have been detected using combined electrospray ionization (ESI) and ion mobility (IM) mass spectrometry (MS) in monolayer-protected silver clusters.

38 citations


Journal ArticleDOI
TL;DR: Highly organized crossed bilayer assemblies of nanowires are made using directed hydrogen bonding between the protecting ligand shells of atomically precise cluster molecules anchored on NWs.
Abstract: Highly organized crossed bilayer assemblies of nanowires (NWs) are made using directed hydrogen bonding between the protecting ligand shells of atomically precise cluster molecules anchored on NWs. Layers of quantum clusters remain sandwiched between two neighboring NWs at a defined distance, dictated by the core-size of the cluster, while the orientation of the ligands in space dictates the interlayer geometry.

Journal ArticleDOI
TL;DR: Large surface area, appropriate chemical functionalities exposed, and easiness of desorption due to weaker interactions of the analyte species are the specific advantages of nanofibers for this application.
Abstract: In this paper, desorption electrospray ionization mass spectrometry (DESI MS)-based molecular analysis and imprint imaging using electrospun nylon-6 nanofiber mats are demonstrated for various analytical contexts. Uniform mats of varying thicknesses composed of ∼200 nm diameter fibers were prepared using needleless electrospinning. Analytical applications requiring rapid understanding of the analytes in single drops, dyes, inks, and/or plant extracts incorporated directly into the nanofibers are discussed with illustrations. The possibility to imprint patterns made of printing inks, plant parts (such as petals, leaves, and slices of rhizomes), and fungal growth on fruits with their faithful reproductions on the nanofiber mats is illustrated with suitable examples. Metabolites were identified by tandem mass spectrometry data available in the literature and in databases. The results highlight the significance of electrospun nanofiber mats as smart surfaces to capture diverse classes of compounds for rapid d...

Journal ArticleDOI
TL;DR: An ambient solution-state method for making uniform nanobrushes composed of oriented 1D silver nanowires (NWs) with aspect ratios of 10(2) -10(4) is reported.
Abstract: An ambient solution-state method for making uniform nanobrushes composed of oriented 1D silver nanowires (NWs) with aspect ratios of 10(2) -10(4) is reported. These structures are grown over cm(2) areas on conducting surfaces. Assemblies of NWs form uniform nanobrush structures, which can capture micrometer-sized objects, such as bacteria and particulate matter. Variation in composition produces unique structures with catalytic properties.

Journal ArticleDOI
TL;DR: The development of a highly selective sensitive fluorescent detection of acetylcholine using bovine serum albumin (BSA) protected atomically precise clusters of gold suggests that AuQC@BSA-AChE has an excellent potential to be used for diagnosis of various neuropsychological and neuropsychiatric disorders.

Journal ArticleDOI
TL;DR: This study provides proof of concept illustrating NCL-APT-based targeted therapeutic strategy and use of Desorption electrospray ionization mass spectrometry (DESI MS)-based lipid imaging in monitoring therapeutic responses in RB.
Abstract: Retinoblastoma (RB) is an intraocular childhood tumor which, if left untreated, leads to blindness and mortality. Nucleolin (NCL) protein which is differentially expressed on the tumor cell surface, binds ligands and regulates carcinogenesis and angiogenesis. We found that NCL is over expressed in RB tumor tissues and cell lines compared to normal retina. We studied the effect of nucleolin-aptamer (NCL-APT) to reduce proliferation in RB tumor cells. Aptamer treatment on the RB cell lines (Y79 and WERI-Rb1) led to significant inhibition of cell proliferation. Locked nucleic acid (LNA) modified NCL-APT administered subcutaneously (s.c.) near tumor or intraperitoneally (i.p.) in Y79 xenografted nude mice resulted in 26 and 65% of tumor growth inhibition, respectively. Downregulation of inhibitor of apoptosis proteins, tumor miRNA-18a, altered serum cytokines, and serum miRNA-18a levels were observed upon NCL-APT treatment. Desorption electrospray ionization mass spectrometry (DESI MS)-based imaging of cell lines and tumor tissues revealed changes in phosphatidylcholines levels upon treatment. Thus, our study provides proof of concept illustrating NCL-APT-based targeted therapeutic strategy and use of DESI MS-based lipid imaging in monitoring therapeutic responses in RB.

Journal ArticleDOI
30 Jun 2016-PLOS ONE
TL;DR: Ambient ionization mass spectrometric imaging of all parts of the seedling of Dysoxylum binectariferum Hook (Meliaceae) was performed to reconstruct the molecular distribution of rohitukine (Rh) and related compounds, finding Rh was predominantly distributed in the main roots, collar region of the stem, and young leaves.
Abstract: Ambient ionization mass spectrometric imaging of all parts of the seedling of Dysoxylum binectariferum Hook. f (Meliaceae) was performed to reconstruct the molecular distribution of rohitukine (Rh) and related compounds. The species accumulates Rh, a prominent chromone alkaloid, in its seeds, fruits, and stem bark. Rh possesses anti-inflammatory, anti-cancer, and immuno-modulatory properties. Desorption electrospray ionization mass spectrometry imaging (DESI MSI) and electrospray ionization (ESI) tandem mass spectrometry (MS/MS) analysis detected Rh as well as its glycosylated, acetylated, oxidized, and methoxylated analogues. Rh was predominantly distributed in the main roots, collar region of the stem, and young leaves. In the stem and roots, Rh was primarily restricted to the cortex region. The identities of the metabolites were assigned based on both the fragmentation patterns and exact mass analyses. We discuss these results, with specific reference to the possible pathways of Rh biosynthesis and translocation during seedling development in D. binectariferum.

Journal ArticleDOI
TL;DR: Studies confirm a two-step mechanism of silver release, first forming silver ions at the metal surface and later complexation of ionic silver with glucose; such complexes have been detected by mass spectrometry.
Abstract: Unprecedented silver ion leaching, in the range of 0.7 ppm was seen when metallic silver was heated in water at 70 °C in presence of simple carbohydrates, such as glucose, making it a green method of silver extraction. Extraction was facilitated by the presence of anions, such as carbonate and phosphate. Studies confirm a two-step mechanism of silver release, first forming silver ions at the metal surface and later complexation of ionic silver with glucose; such complexes have been detected by mass spectrometry. Extraction leads to microscopic roughening of the surface making it Raman active with an enhancement factor of 5×108.

Journal ArticleDOI
TL;DR: It is shown that selective transformation of the ligand shell structure of the aspicule Ag44(4-MBA)30 was modified in a precise, site-specific manner and can be used to create molecular patterns, which may be important in chemistry at biphasic interfaces.
Abstract: The ligand shell structure of the aspicule Ag44(4-MBA)30 (MBA: mercaptobenzoic acid, in the thiolate form) was modified in a precise, site-specific manner. Laser irradiation at 633 nm of a monolayer assembly of plasmonic Ag nanoparticles (NPs) covered with Ag44(4-MBA)30 clusters leads to decarboxylation of 4-MBA ligands forming thiophenolate (TP) ligands. While the molecular identity and integrity of aspicules post laser irradiation were confirmed by ESI MS, time-dependent SERS spectra and computational studies suggest that the phenomenon of decarboxylation is limited to the 4-MBA ligands facing the NP surface. This creates modified Ag44 clusters, with 4-MBA ligands on one side and TP ligands on the other, giving them a two-faced (Janus) ligand structure. The ligand distribution of such clusters gets equilibrated in solution. We show that such selective transformation can be used to create molecular patterns. Janus clusters may be important in chemistry at biphasic interfaces.

Journal ArticleDOI
TL;DR: This review highlights the crucial role of the solvent and sample spotting surfaces as the backbone of the breakthroughs achieved in the analysis of biological materials of plant, bacterial, animal and human origins.
Abstract: DESI MS, has been successfully employed for the analysis of molecules from a wide variety of surfaces without prior sample treatment. The efficiency of DESI MS relies on various parameters. However, those that critically affect the ionization of biological samples include: the solvent system and the sample or sample spotting surfaces. These parameters gain unequivocal dominance specially whilst dealing with sensitive and intricate biological samples. This review is meant to capture the attention of the DESI-MS researchers towards the crucial role of the solvent and sample spotting surfaces for successful biological DESI-MS. This review highlights these parameters as the backbone of the breakthroughs achieved in the analysis of biological materials of plant, bacterial, animal and human origins.

Journal ArticleDOI
TL;DR: The first atomically precise and monolayer protected iridium cluster in solution, Ir9(PET)6 (PET -2-phenyethanethiol) was synthesized via a solid state method.
Abstract: The first atomically precise and monolayer protected iridium cluster in solution, Ir9(PET)6 (PET – 2-phenyethanethiol) was synthesized via a solid state method. The absence of a plasmonic band at ∼350 nm, expected in the UV/Vis spectra for spherical Ir particles of 10 nm size indicated that the synthesized cluster is smaller than this dimension. Small angle X-ray scattering (SAXS) showed that the cluster has a particle size of ∼2 nm in solution which was confirmed by transmission electron microscopy (TEM). The blue emission of the cluster is much weaker than many noble metal clusters investigated so far. X-ray photoelectron spectroscopy (XPS) measurements showed that all Ir atoms of the cluster are close to the zero oxidation state. The characteristic S–H vibrational peak of PET at 2560 cm−1 was absent in the FT-IR spectrum of the cluster indicating RS–Ir bond formation. The molecular formula of the cluster, Ir9(PET)6 was assigned based on the most significant peak at m/z 2553 in the matrix assisted laser desorption ionization mass spectrum (MALDI MS), measured at the threshold laser intensity. Density functional theory calculations on small Ir@SCH3 and Ir@PET clusters and comparison of the predictions with the IR and 1H-NMR spectra of Ir9(PET)6 suggested that the PET ligands have two distinct structural arrangements and are likely to be present as bridging thiolates –(Ir–SR–Ir)– and singly attached thiolates –(Ir–SR).

Journal ArticleDOI
TL;DR: In this paper, a highly luminescent mixed chalcogenide silver cluster, Ag56Se13S15 cluster of Ag2X stoichiometry, protected with a 4-tert-butylbenzyl mercaptan ligand has been synthesized and characterized using diverse tools of analysis such as mass spectrometry, elemental analysis, thermogravimetry and X-ray diffraction confirmed this composition.
Abstract: A highly luminescent (quantum yield 21%) mixed chalcogenide silver cluster, Ag56Se13S15 cluster of Ag2X stoichiometry, protected with a 4-tert-butylbenzyl mercaptan ligand has been synthesized and characterized Investigation using diverse tools of analysis such as mass spectrometry, elemental analysis, thermogravimetry and X-ray diffraction confirmed this composition The cluster emits in solution and in the solid state and has been deposited on oxide supports to get red emitting films The specificity of cluster emission to the mercuric ion Hg(II), among a range of heavy metal ions, was used to develop a sensor, which shows sensitivity down to 1 ppb A pH paper like visual detector was developed by combining the Hg(II)-sensitive emission of the cluster and the insensitive emission of fluorescein isothiocyanate The test strip showed visual detection down to 1 ppb in real water samples


Journal ArticleDOI
TL;DR: Electrospray ionization mass spectrometry, Raman spectroscopy, and theoretical studies describe the formation of such a complex cluster from a reduced and acidified aqueous solution of molybdate.
Abstract: The formation pathway of a closed spherical cluster [Mo132], starting from a library of building blocks of molybdate anions, has been reported. Electrospray ionization mass spectrometry, Raman spectroscopy, and theoretical studies describe the formation of such a complex cluster from a reduced and acidified aqueous solution of molybdate. Understanding the emergence of such an enormous spherical model cluster may lead to the design of new clusters in the future. Formation of such a highly symmetric cluster is principally controlled by charge balance and the emergence of more symmetric structures at the expense of less symmetric ones.

Journal ArticleDOI
TL;DR: In this article, it is proposed that diffusion of CH2Cl2 into amorphous solid water (ASW) occurs and it crystallizes within the pores of ASW, which increases the transition temperature.
Abstract: Dichloromethane (CH2Cl2) thin films deposited on Ru(0001) at low temperatures (∼80 K or lower) undergo a phase transition at ∼95 K, manifested by the splitting of its wagging mode at 1265 cm–1, due to factor group splitting. This splitting occurs at relatively higher temperatures (∼100 K) when amorphous solid water (ASW) is deposited over it, with a significant reduction in intensity of the high-wavenumber component (of the split peaks). Control experiments showed that the intensity of the higher wavenumber peak is dependent on the thickness of the water overlayer. It is proposed that diffusion of CH2Cl2 into ASW occurs and it crystallizes within the pores of ASW, which increases the transition temperature. However, the dimensions of the CH2Cl2 crystallites get smaller with increasing thickness of ASW with concomitant change in the intensity of the factor group split peak. Control experiments support this suggestion. We propose that the peak intensities can be correlated with the porosity of the ice film....

Journal ArticleDOI
TL;DR: The self-assembly and high temperature behavior of AB/B′ type block copolymer/homopolymer blends containing polyacrylonitrile (PAN) polymers were studied for the first time in this paper.
Abstract: The self-assembly and high temperature behavior of AB/B′ type block copolymer/homopolymer blends containing polyacrylonitrile (PAN) polymers were studied for the first time. Here, microphase separated nanostructures were formed in the poly(methyl methacrylate-b-polyacrylonitrile) (PMMAN) block copolymer and their blends with homopolymer PAN at various blend ratios. Additionally, these nanostructures were transformed into porous carbon nanostructures by sacrificing PMMA blocks via pyrolysis. Spherical and worm like morphologies were observed in both TEM and AFM images at different compositions. The thermal and phase behavior examinations showed good compatibility between the blend components in all studied compositions. The PAN homopolymer (B′) with a comparatively higher molecular weight than the corresponding block (B) of the block copolymer is expected to exhibit ‘dry brush’ behavior in this AB/B′ type system. This study provides a basic understanding of the miscibility and phase separation in the PMMAN/PAN system, which is important in the nanostructure formation of bulk PAN based materials with the help of block copolymers to develop advanced functional materials.

Journal ArticleDOI
01 Aug 2016-Carbon
TL;DR: In this paper, the acyl chloride/hydroxyl and amine/carboxylic functionalities of carbon nanotubes are attached to their surfaces, resulting in the formation of chemically modified graphene products.

Journal ArticleDOI
TL;DR: In this article, a voltage pulse induced multilevel resistive switching (MRS) with as many as five states under ambient conditions with high degrees of retention and endurance was investigated.
Abstract: © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Resistive random access memory (RRAM) is the most promising candidate for next generation nonvolatile memory. In this article, resistive switching in PdO thin film is investigated. The fabricated in-plane devices showed voltage pulse induced multilevel resistive switching (MRS) with as many as five states under ambient conditions with high degrees of retention and endurance. The I–V characteristics of the different memory states are linear and only a small reading voltage (≈10 mV) is necessary. Raman mapping of PdO (B1g mode, 650 cm–1) and temperature-dependent electrical transport measurements provide an insight into possible redox mechanism involving PdO/Pd particles. For the first time, the switching efficiency of a MRS device is uniquely defined in terms of a parameter called “multiplex number (M),” which is the sum of the total number of memory states and the ratio between the number of switching events observed in a device and the total number of possible switching events. The present PdO MRS device exhibits the highest M value compared to the values evaluated from the literature examples. Such high performance MRS in PdO devices makes them potential candidates for RRAM and neuromorphic circuit applications.

Journal ArticleDOI
TL;DR: The results indicate that DESI MS has a potential ability to rapidly monitor aptamer-mediated cancer therapy and accelerate the drug discovery process.
Abstract: The importance of the polo-like kinase 1 (PLK1) gene is increasing substantially both as a biomarker and as a target for highly specific cancer therapy. This is due to its involvement in multiple points of cell progression and carcinogenesis. PLK1 inhibitors’ efficacy in treating human cancers has been limited due to the lack of a specific targeting strategy. Here, we describe a method of targeted downregulation of PLK1 in cancer cells and the concomitant rapid detection of surface lipidomic perturbations using desorption electrospray ionization mass spectrometry (DESI MS). The efficient delivery of siRNA targeting PLK1 gene selectively to the cancer cells is achieved by targeting overexpressed cell surface epithelial cell adhesion molecule (EpCAM) by the EpDT3 aptamer. The chimeric aptamer (EpDT3-siPLK1) showed the knockdown of PLK1 gene expression and PLK1 protein levels by quantitative PCR and western blotting, respectively. The abundant surface lipids, phosphatidylcholines (PCs), such as PC(32:1) (m/z 754.6), PC(34:1) (m/z 782.6), and PC(36:2) (m/z 808.6), were highly expressed in MCF-7 and WERI-RB1 cancer cells compared to normal MIO-M1 cells and they were observed using DESI MS. These overexpressed cell surface lipids in the cancer cells were downregulated upon the treatment of EpDT3-siPLK1 chimera indicating a novel role of PLK1 to regulate surface lipid expression in addition to the efficient selective cancer targeting ability. Our results indicate that DESI MS has a potential ability to rapidly monitor aptamer-mediated cancer therapy and accelerate the drug discovery process.

Journal ArticleDOI
TL;DR: The reactivity of the 2D nanosheets of MoS2 with silver ions in solution, leading to their spontaneous morphological and chemical transformations, is reported and points to the stability of the metal-sulphur bond in determining the chemical compositions of the final products.
Abstract: The reactivity of the 2D nanosheets of MoS2 with silver ions in solution, leading to their spontaneous morphological and chemical transformations, is reported. This unique reactivity of the nanoscale form of MoS2 was in stark contrast to its bulk counterpart. While the gradual morphological transformation involving several steps has been captured with an electron microscope, precise chemical identification of the species involved was achieved by electron spectroscopy and mass spectrometry. The energetics of the system investigated supports the observed chemical transformation. The reaction with mercury and gold ions shows similar and dissimilar reaction products, respectively and points to the stability of the metal-sulphur bond in determining the chemical compositions of the final products.

Journal ArticleDOI
TL;DR: In this article, a hybrid material with intrinsically high stability in water that is prepared using naturally abundant ingredients which releases carbonate constantly and in a controlled fashion was described, tested with E. coli and MS2 phage.
Abstract: Silver, a metal with phenomenal commercial importance has been exploited in its ionic form in the field of water purification, with the objective of delivering microbially safe drinking water. Silver released at such concentrations is unrecoverable and has to be reduced to ensure sustainable utilization of the metal. We have shown that small concentrations of carbonate can effectively bring down the amount of silver ion used for microbial disinfection by half. Implementation of this finding requires constant carbonate releasing materials in natural water for an extended period. In this work, we describe a hybrid material with intrinsically high stability in water that is prepared using naturally abundant ingredients which releases carbonate constantly and in a controlled fashion. This composition in conjunction with reduced silver ion concentration delivers mircobially safe water, tested with E. coli and MS2 phage. Use of constant carbonate releasing material for antimicrobial applications can reduce the ...