Soubantika Palchoudhury - Academia.edu (original) (raw)

Papers by Soubantika Palchoudhury

Magnetic Nanomaterials - Fundamentals, Synthesis and Applications

ABSTRACTThe COVID-19 pandemic shut down undergraduate research programs across the U.S. Twenty-th... more ABSTRACTThe COVID-19 pandemic shut down undergraduate research programs across the U.S. Twenty-three sites offered remote undergraduate research programs in the life sciences during summer 2020. Given the unprecedented offering of remote research experiences, we carried out a study to describe and evaluate these programs. Using structured templates, we documented how programs were designed and implemented, including who participated. Through focus groups and surveys, we identified programmatic strengths and shortcomings as well as recommendations for improvements from the perspectives of participating students. Strengths included the quality of mentorship, opportunities for learning and professional development, and development of a sense of community. Weaknesses included limited cohort building, challenges with insufficient structure, and issues with technology. Although all programs had one or more activities related to diversity, equity, inclusion, and justice, these topics were ...

Beilstein Journal of Nanotechnology, 2020

Nanoparticles (NPs) are considered as one of the most promising drug delivery vehicles and a next... more Nanoparticles (NPs) are considered as one of the most promising drug delivery vehicles and a next-generation solution for current medical challenges. In this context, variables related to flow of NPs such as the quantity of NPs lost during transport and flow trajectory greatly affect the clinical efficiency of NP drug delivery systems. Currently, there is little knowledge of the physical mechanisms dominating NP flow inside the human body due to the limitations of available experimental tools for mimicking complex physiological environments at the preclinical stage. Here, we report a coupled experimental and computational fluid dynamics (CFD)-based novel in vitro approach to predict the flow velocity and binding of NP drug delivery systems during transport through vasculature. Poly(hydroxyethyl)methacrylate hydrogels were used to form soft cylindrical constructs mimicking vascular sections as flow channels for synthesized iron oxide NPs in these first-of-its-kind transport experimen...

Journal of Nanomaterials, 2020

Journal of Nanoscience and Nanotechnology, 2020

In this work, we report a facile approach to modify the magnetic and electrical property of Hipco... more In this work, we report a facile approach to modify the magnetic and electrical property of Hipco single-walled carbon nanotubes (SWCNTs) by attaching iron oxide nanoparticles (FeNPs). The Raman spectra of FeNP-SWCNTs revealed an apparent intensity reduction of metallic peaks in Radial breathing mode (RBM) region, which indicates the ratio change between the metallic and semiconducting component of SWCNTs after modification. Distinctive magnetic and electric resistance properties of FeNP-SWCNTs were found to be associated with the different shapes of FeNPs. The specific FeNP examples as showcased in this work can be applied to tune the electric and magnetic properties of other nanostructured materials in general and shed light on various electronic and magnetic applications.

Journal of Nanomaterials, 2019

There is an emerging scientific interest in the use of nanoparticle fertilizers for enhanced agri... more There is an emerging scientific interest in the use of nanoparticle fertilizers for enhanced agricultural and bioenergy crop production to meet the growing food and energy demands of the world. The objective of designing the nanoparticle fertilizers is to effectively deliver the required nutrients for the plants without adding large quantities of fertilizer to the environment. However, most reports on nanoparticle fertilizers so far, involved the addition of nanoparticles to the hydroponic system or the soil. In this study, we report a new modified seed presoak strategy using a drop of Fe-enriching hematite nanoparticle dispersion to enhance plant growth and production in four different legume species, i.e., chickpea, green gram, black bean, and red bean. The hematite nanoparticle fertilizer drop promoted a 230-830% increase in plant growth with green gram showing the highest increase, based on our prolonged and statistically reliable growth studies. In general, we observed an incre...

C, 2017

Hydrogen is an efficient fuel which can be generated via water splitting, however hydrogen evolut... more Hydrogen is an efficient fuel which can be generated via water splitting, however hydrogen evolution occurs at high overpotential, and efficient hydrogen evolution catalysts are desired to replace state-of-the-art catalysts such as platinum. Here, we report an advanced electrocatalyst that has low overpotential, efficient charge transfers kinetics, low Tafel slope and durable. Carbon nanofibers (CNFs), obtained by carbonizing electrospun fibers, were decorated with MoS 2 using a facile hydrothermal method. The imaging of catalyst reveals a flower like morphology that allows for exposure of edge sulfur sites to maximize the HER process. HER activity of MoS 2 decorated over CNFs was compared with MoS 2 without CNFs and with commercial MoS 2. MoS 2 grown over CNFs and MoS 2-synthesized produced about 374 and 98 times higher current density at −0.30 V (vs. Reversible Hydrogen Electrode, RHE) compared with the MoS 2-commercial sample, respectively. MoS 2-commercial, MoS 2-synthesized and MoS 2 grown over CNFs showed a Tafel slope of 165, 79 and 60 mV/decade, capacitance of 0.99, 5.87 and 15.66 mF/cm 2 , and turnover frequency of 0.013, 0.025 and 0.54 s −1 , respectively. The enhanced performance of MoS 2-CNFs is due to large electroactive surface area, more exposure of edge sulfur to the electrolyte, and easy charge transfer from MoS 2 to the electrode through conducting CNFs.

Langmuir : the ACS journal of surfaces and colloids, Jun 18, 2017

Proteins are widely utilized as templates in biomimetic synthesis of gold nanocrystals. However, ... more Proteins are widely utilized as templates in biomimetic synthesis of gold nanocrystals. However, the role of proteins in mediating the pathways for gold nucleation and growth is not well understood, in part because of the lack of spatial resolution in probing the complicated biomimetic mineralization process. Self-assembled protein cages, with larger size and symmetry, can facilitate in the visualization of both biological and inorganic components. We have utilized bacteriophage P22 protein cages of ~ 60 nm diameter for investigating the nucleation and growth of gold nanocrystals. By adding a gold precursor into solution with pre-existing protein cages and a reducing agent, gold nuclei/prenucleation clusters form in solution, which then locate and attach to specific binding sites on protein cages, and further grow to form gold nanocrystals. In contrast, addition of the reducing agent into solution with incubated gold precursor and protein cages leads to formation of gold nuclei/pren...

Journal of Materials Research, 2016

Protein cage based nanoarchitectures hold great potential in the fields of energy, catalysis, and... more Protein cage based nanoarchitectures hold great potential in the fields of energy, catalysis, and bio-applications owing to their ability to tune material’s properties in a benign biomimetic approach. We demonstrate the self-assembly of bacteriophage P22 using inorganic nanoparticles and dendrimers for the first time. Inorganic nanoparticles (iron oxide, CoFe2O4, and Au) and polyamidoamine serve as model systems for rigid and soft linker materials, respectively, to induce P22 assembly via electrostatic interaction. We observed distinctly different packing of P22 using nanoparticles as compared to the polyamidoamine polymer. Notably, the ratio of nanoparticle: P22 and ligand packing on the nanoparticle surface are dominant controls for this assembly. The best results are obtained at 6.5:1 nanoparticle:P22 number ratio in the presence of 50 mM NaCl, pH = 6. In contrast, dense area assembly of P22 is observed at 8:1 polyamidoamine:P22 number ratio with 1 M NaCl (pH ∼ 7.5) for the dendrimer.

New Journal of Chemistry, 2015

The next generation of flexible energy storage devices based on CoMoO4 for high-temperature appli... more The next generation of flexible energy storage devices based on CoMoO4 for high-temperature applications were fabricated and tested.

Scientific reports, Jan 20, 2015

Binder free nanostructured NiCo2O4 were grown using a facile hydrothermal technique. X-ray diffra... more Binder free nanostructured NiCo2O4 were grown using a facile hydrothermal technique. X-ray diffraction patterns confirmed the phase purity of NiCo2O4. The surface morphology and microstructure of the NiCo2O4 analyzed by scanning electron microscopy (SEM) showed flower-like morphology composed of needle-like structures. The potential application of binder free NiCo2O4 as an electrode for supercapacitor devices was investigated using electrochemical methods. The cyclic voltammograms of NiCo2O4 electrode using alkaline aqueous electrolytes showed the presence of redox peaks suggesting pseudocapacitance behavior. Quasi-solid state supercapacitor device fabricated by sandwiching two NiCo2O4 electrodes and separating them by ion transporting layer. The performance of the device was tested using cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The device showed excellent flexibility and cyclic stability. The temperature dependent charge storage...

Chemical Communications, 2016

A new family of semiconductors Cu2ZnAS4−x and CuZn2AS4 (A = Al, Ga, In) that absorb strongly at v... more A new family of semiconductors Cu2ZnAS4−x and CuZn2AS4 (A = Al, Ga, In) that absorb strongly at visible wavelengths has been synthesized as nanocrystals.

Characterization of Nanomaterials in Complex Environmental and Biological Media, 2015

Abstract Measuring the concentration of Nanomaterials (NMs) is a key to understanding NM fate, be... more Abstract Measuring the concentration of Nanomaterials (NMs) is a key to understanding NM fate, behaviour, exposure and risk. This chapter discusses three most commonly measured particle concentration metrics, namely mass, surface area and number and their environmental/toxicological relevance; methods used to measure these metrics; and sample preparation for selected methods, including microscopy and inductively coupled plasma–mass spectrometry (ICP-MS). Available analytical techniques for mass, surface area and number concentration measurements are systematically evaluated in terms of sensitivity/detection range for NM mass, representing NM surfaces in dispersion, distinguishing NMs in complex medium and minimizing sampling artifacts in number distributions. Based on these criteria, mass concentration is best measured on the highly sensitive ICP-MS. For number concentrations of complex systems, high resolution microscopy techniques are recommended, using validated sample preparation methods. Several methods are available for surface area measurement, like nuclear magnetic resonance but few of these have been validated for NMs in complex media.

Environmental science & technology, Jan 16, 2014

Catastrophic oil spills and oil from waste waters such as bilge and fracking waters pose major en... more Catastrophic oil spills and oil from waste waters such as bilge and fracking waters pose major environmental concerns. The limitations of existing cleanup techniques for benign oil remediation has inspired a recent scientific impetus to develop oil-absorbing smart nanomaterials. Magnetic nanocomposites were here designed to allow easy recovery from various systems. In this study, sorption of reference MC252 oil with easy-to-synthesize and low-cost hydrophilic polyvinylpyrrolidone-coated iron oxide nanoparticles is reported for the first time. The one-step modified polyol synthesis in air directly generates water-soluble nanoparticles. Stable polyvinylpyrrolidone-coatings are known to minimize environmental alterations of nanoparticles from aggregation and other processes. Iron oxide provides effective magnetic actuation, while both PVP and iron oxide have low toxicity. These nanoparticles gave quantitative (near 100%) oil removal under optimized conditions. The facile synthesis and ...

Chemistry of Materials, 2015

The ever-growing need for energy generation and storage applications demands development of mater... more The ever-growing need for energy generation and storage applications demands development of materials with high performance and long term stability. A sizeable number of chalcogenide-based materials have been investigated for supercapacitor applications. Layerstructured chalcogenides are advantageous in terms of providing large surface area with good ionic conductivity and ability to host a variety of atoms or ions between the layers. CuSbS 2 is a ternary layered chalcogenide material that is composed of earth abundant and less-toxic elements. For the first time we have developed a simple colloidal method for the synthesis of CuSbSe x S 2-x mesocrystals over the whole composition range (0 ≤ x ≤ 2) by substitution of S with Se. Our approach yields mesocrystals with belt-like morphology for all the compositions. X-ray diffraction results show that substitution of sulfur with selenium in CuSbS 2 enables tuning the width of the interlayer gap between the layers. In order to investigate the suitability of CuSbSe x S 2-x mesocrystals for supercapacitor applications, we have carried out electrochemical measurements by cyclic voltammetry and galvanostatic charge-discharge measurements in 3M KOH, NaOH and LiOH electrolytes. Our investigations reveal that the mesocrystals exhibit promising specific capacitance values with excellent cyclic stability. The unique properties of CuSbSe x S 2-x mesocrystals make them attractive both for solar energy conversion and energy storage applications.

RSC Adv., 2014

Nanoflower-shaped iron oxide nanoparticles (FeNPs) were attached onto graphene nanoribbons (GNRs).

Particulate Science and Technology, 2014

We report a simple phase transfer based synthesis route for two novel anisotropic water soluble i... more We report a simple phase transfer based synthesis route for two novel anisotropic water soluble iron oxide nanoparticle shapes, namely, nanoplates and nanoflowers. The nanoplates and nanoflowers are initially prepared in an organic solvent via a modified ''heat-up'' method. Then, the crystalline nanoparticles are rendered hydrophilic via sonication in the presence of dextran and water. These nanoparticles are highly monodisperse and superparamagnetic at room temperature. High resolution transmission electron microscopy indicates that the iron oxides cores are not affected by the phase transfer. Dextran coating is confirmed by dynamic light scattering, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The obtained dextran coverage was 26 wt% for the nanoplates and 37 wt% for the nanoflowers. The nanoplates and nanoflowers were not only water soluble, but also remained stable at different pH (4-7) and in common aqueous buffer solutions. Thorough characterizations of the nonspherical iron oxide nanoparticles indicate that these particles could be useful for potential biomedical applications and magnetic resonance imaging.

Nano Letters, 2011

Iron oxide nanowhiskers with dimensions of approximately 2 Â 20 nm were successfully synthesized ... more Iron oxide nanowhiskers with dimensions of approximately 2 Â 20 nm were successfully synthesized by selectively heating an iron oleate complex. Such nanostructures resulted from the difference in the ligand coordination microenvironments of the Fe(III) oleate complex, according to our electronic structure calculations and thermogravimetric analysis. A ligand-directed growth mechanism was subsequently proposed to rationalize the growth process. The formation of the nanowhiskers provides a unique example of shape-controlled nanostructures, offering additional insights into nanoparticle synthesis.

Langmuir, 2011

The water dispensability and stability of high quality iron oxide nanoparticles synthesized in or... more The water dispensability and stability of high quality iron oxide nanoparticles synthesized in organic solvents are major issues for biomedical and biological applications. In this paper, a versatile approach for preparing water-soluble iron oxide nanoparticles with great stability and selective surface functionality (-COOH, -NH(2), or -SH) was demonstrated. The hydrophobic nanoparticles were first synthesized by the thermal decomposition of an iron oleate complex in organic solvent. Subsequently, the hydrophobic coatings of nanoparticles were replaced with poly(acrylic acid) , polyethylenimine, or glutathione, yielding charged nanoparticles in aqueous solution. Two parameters were found to be critical for obtaining highly stable nanoparticle dispersions: the original coating and the surfactant-to-nanoparticle ratio. These charged nanoparticles exhibited different stabilities in biological buffers, which were directly influenced by the surface coatings. This report will provide significant practical value in exploring the biological or biomedical applications of iron oxide nanoparticles.

Langmuir, 2012

We report a facile approach to the conjugation of protein-encapsulated gold fluorescent nanoclust... more We report a facile approach to the conjugation of protein-encapsulated gold fluorescent nanoclusters to the iron oxide nanoparticles through catechol reaction. This method eliminates the use of chemical linkers and can be readily extended to the conjugation of biological molecules and other nanomaterials onto nanoparticle surfaces. The key to the success was producing water-soluble iron oxide nanoparticles with active catechol groups. Further, advanced electron microscopy analysis of the integrated gold nanoclusters and iron oxide nanoparticles provided direct evidence of the presence of a single fluorescent nanocluster per protein template. Interestingly, the integrated nanoparticles exhibited enhanced fluorescent emission in biological media. These studies will provide significantly practical value in chemical conjugation, the development of multifunctional nanostructures, and exploration of multifunctional nanoparticles for biological applications.