Sensitive Detection of Hg2+ and l-Cysteine through Optical Asymmetry-Tuned Fluorescence Switch Off-On Behavior in N-Doped Chiral Carbon Dot
Authors: Angana Bhattacharya, Dipanjan Samanta, Manisha Shaw, Md Abdus Salam Shaik, Rajarshi Basu, Imran Mondal, Amita Pathak*Journal: ACS Applied Bio Materials Year: 2024 Posted: 14 Dec 2024
Chirality Cascade and Atomic-Scale Helicity in Hierarchical Chiral CuO Nanostructures
Authors: Dipanjan Samanta, Manisha Shaw, Md Abdus Salam Shaik, Rajarshi Basu, Imran Mondal, Angana Bhattacharya, and Amita Pathak*Journal: The Journal of Physical Chemistry C Year: 2024 Posted: 12 Sep 2024
Influence of Nitrogen-Doped Carbon Dots on H• Radical-Mediated Au–H Formation in the Hydrogenation of 4-Nitrophenol Using NCDs-Au Nanohybrids
Authors: Imran Mondal, Dipanjan Samanta, Md Abdus Salam Shaik, Manisha Shaw, Angana Bhattacharya, Rajarshi Basu, Amita Pathak*Journal: Langmuir Year: 2024 Posted: 26 Aug 2024
Biocompatible fluorescent carbon nanoparticles as nanocarriers for targeted delivery of tamoxifen for regression of Breast carcinoma
Authors: Nagaprasad Puvvada, Md. Abdus Salam Shaik, Dipanjan Samanta, Manisha Shaw, Imran Mondal, Rajarshi Basu, Angana Bhattachariya, Amita PathakJournal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy Year: 2024 Posted: 26 Jun 2024
Chiral carbon dots: a smart choice for inhibition of human serum albumin fibrillation
Authors: Suraj Konar, Shubhatam Sen and Amita PathakVol: 48 Pages: 2933-2944Journal: New Journal of Chemistry Year: 2024 Posted: 10 May 2024
“Click” Chemistry Assisted Synthesis of Magnetite-CNT Nanohybrid Supported Gold Nanoparticles for Enhanced Catalytic Reduction of 4-Nitrophenol
Authors: Imran Mondal, Dipanjan Samanta, Md Abdus Salam Shaik, , Rajarshi Basu, Angana Bhattacharya, Manisha Shaw, Amita PathakJournal: ChemistrySelect Year: 2023 Posted: 22 Dec 2023
Ethanol Gas Sensors Using Semi-Hedgehog-like CuO Nanostructures: Studying the Role of Oxygen Vacancies, Unsaturated Cu-Sites, and Hole Accumulation Layer
Authors: Manisha Shaw, Dipanjan Samanta, Md Abdus Salam Shaik, Rajarshi Basu, Debasish Das*, Amita Pathak*Journal: ACS Applied Nano Material Year: 2023 Posted: 29 Nov 2023
White light emission from helically stacked humin-mimic based H-aggregates in heteroatom free carbon dots
Authors: Md Abdus SalamShaik1, DipanjanSamanta1, Ankit Kumar Sharma, Manisha Shaw, Sayan Prodhan, Rajarshi Basu, Imran Mondal, Shailab Singh, Prasanta Kumar Dutta, Amita PathakVol: 15 Pages: 19238 - 19254Journal: Nanoscale Year: 2023 Posted: 22 Nov 2023
Authors: Rosy Rahman, Priyanka Rani, Subhadip Ghosh, Anupam Midya , Amita Pathak* *, and Tapan Kumar Nath*Journal: ACS Applied Energy Materials Year: 2023 Posted: 13 Oct 2023
Layered transition metal dichalcogenides (TMDCs) such as molybdenum disulfide (MoS2) with mixed phases (1T and 2H) have attracted huge attention as a promising supercapacitor electrode material attributing to their unique physical and electrical properties, abundant catalytically active sites with metallic edges, and high surface area. However, to enhance the electrochemical performance of 1T@2H MoS2 and to overcome the limitations of the stacking between the MoS2 layers, phase engineering and functionalization of MoS2 with polyaniline (PANI) simultaneously are a promising yet challenging way. Herein, we report the tubular uniform growth of PANI on 1T@2H MoS2 templates, where ascorbic acid plays a pivotal role in self-assembling the PANI molecules among themselves. The optimized PANI-\/1T@2H MoS2 hybrid functionalized with l-ascorbic acid (L-AA), denoted as PM2, delivers a high specific capacitance of 618 F\/g at a current density of 1 A\/g and a good rate retention up to 73% with the increase in current density from 1 to 10 A\/g in a three-electrode system. Interestingly, the symmetric supercapacitor (SSC) integrated using the PM2 hybrid delivers efficient capacitive property (160 F\/g at 0.3 A\/g), energy, and power density (8 Wh\/kg and 6.1 kW\/kg). It has been evidenced that the PM2 hybrid exhibits excellent electrochemical properties as a supercapacitor electrode material, having capacitive retention up to 98.1% even after completing 8000 cycles at a current density of 2 A\/g. Additionally, PM2 SSCs possess an excellent degree of mechanical properties and flexibility, and they are able to power a red LED successfully when connected in series. Furthermore, the experimentally observed results are compared and justified with the theoretical findings. Our strategy of growing PANI onto L-AA functionalized 1T@2H MoS2 provides a possible pathway to enhance the electrochemical performance of PANI\/MoS2-based hybrid materials for the design of future-generation energy storage devices.<\/p>")">
Optical Asymmetry and Structural Complexity in Hierarchically Organized Chiral CuO Nanostructures: Insight into the Geometric and Crystallographic Effects on Cooperative Chirality
Authors: Dipanjan Samanta1, Manisha Shaw1, Md Abdus Salam Shaik1, Rajarshi Basu, Imran Mondal, Angana Bhattacharya, and Amita Pathak*Journal: Inorganic Chemistry Year: 2023 Posted: 06 Oct 2023
Carbon Dots as a Fluorescent Probe for Appraising Morphology-Dependent Free-Radical-Scavenging Properties of CuO Nanostructures
Authors: Dr. Suraj Konar, Md. Abdus Salam Shaik, Dipanjan Samanta, Manisha Shaw, Rajarshi Basu, Dr. Madhusudan Kr. Mahto, Imran Mondal, Prof. Amita PathakVol: 8 Pages: Journal: ChemistrySelect Year: 2023 Posted: 20 Jun 2023
Blue-Emissive Nitrogen-Doped Carbon Dots for Picric Acid Detection: Molecular Fluorescence Quenching Mechanism
Authors: Madhusudan Kr. Mahto1 , Dipanjan Samanta1, Manisha Shaw, Md Abdus Salam Shaik, Rajarshi Basu, Imran Mondal, Angana Bhattacharya, and Amita Pathak*Vol: 6 Pages: 8059–8070Journal: ACS Applied Nano Materials Year: 2023 Posted: 04 May 2023
Pyridinic-N-rich carbon dots in IFE-based Turn-off Fluorometric detection of nerve agent Mimic– Diethyl chlorophosphate and multicolor cell imaging
Authors: Imran Mondal, Dipanjan Samanta, Manisha Shaw, Md Abdus Salam Shaik, Madhusudan Kr Mahto, Rajarshi Basu, Angana Bhattacharya, Amita PathakJournal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy Year: 2023 Posted: 25 Feb 2023
Solvent-induced switching between static and dynamic fluorescence quenching of N, S Co-doped carbon dots in sensing of Crotonaldehyde: A detailed systematic study
Authors: Manisha Shaw, Dipanjan Samanta, Md Abdus Salam Shaik, Angana Bhattacharya, Rajarshi Basu, Imran Mondal, Amita PathakVol: 137 Pages: 113600Journal: Optical Materials Year: 2023 Posted: 24 Feb 2023
Cover ART @Inorganic Chemistry
Authors: Manisha Shaw , Dipanjan Samanta, Sharmita Bera, Madhusudan Kr Mahto, Md Abdus Salam Shaik, Suraj Konar, Imran Mondal, Dibakar Dhara, and Amita Pathak*Journal: Inorganic Chemistry Year: 2022 Posted: 04 May 2023
Authors: Manisha Shaw1, Dipanjan Samanta1, Md Abdus Salam Shaik, Angana Bhattacharya, Rajarshi Basu, Imran Mondal, Amita PathakVol: 61 Pages: 14568–14581Journal: Inorganic Chemistry Year: 2022 Posted: 11 Mar 2023
Fluorescent N, S co-doped Carbon Dots for Tartrazine Sensing and Mechanistic Perception of their Radical Scavenging Activity
Authors: Md Abdus SalamShaik, DipanjanSamanta, ManishaShaw, ImranMondal, RajarshiBasu, AmitaPathakJournal: Sensors and Actuators Reports Year: 2022 Posted: 05 Nov 2022
Insights into the Multifunctional Applications of Strategical Co doped MoS2 Nanoflakes
Authors: Rosy Rahman , S. Chaudhuri, Dipanjan Samanta , A. Pathak and T. K. NathJournal: Materials Advances Year: 2022 Posted: 12 Oct 2022
One Order Enhancement of Charge Carrier Relaxation Rate by Tuning Structural and Optical Properties in Annealed Cobalt Doped MoS2 Nanosheets
Authors: Rosy Rahman, Manobina Karmakar, Dipanjan Samanta, Amita Pathak,* Prasanta Kumar Datta* and Tapan Kumar Nath*Journal: New Journal of Chemistry Year: 2022 Posted: 05 Sep 2022
Sensitive detection of auric and sulphide ions using hybrid silver/nitrogen-doped carbon nanoparticles
Authors: Sangeeta Tantubay , Himani Kalita, Amita PathakVol: 330 Pages: 129276Journal: Sensors and Actuators B: Chemical Year: 2021 Posted: 05 Apr 2023
Tuning of structural and optical properties with enhanced catalytic activity in chemically synthesized Co-doped MoS2 nanosheets
Authors: Rosy Rahman, Dipanjan Samanta, Amita Pathak* and Tapan Kumar Nath*Journal: RSC Advances Year: 2021 Posted: 05 Sep 2022
Authors: Suraj Konar, B.N. Prashanth Kumar, Madhusudan Kr. Mahto, Dipanjan Samanta, Md Abdus Salam Shaik, Manisha Shaw, Mahitosh Mandal, Amita PathakVol: 286 Pages: 77-85Journal: Sensors & Actuators: B. Chemical Year: 2019 Posted: 25 Jun 2019
In the present work, we developed nitrogen-doped carbon dots (NCDs) as novel fluorescence probe for the quantitative detection of cysteamine. NCDs were synthesized by a rapid one-pot microwave assisted pyrolysis method using tartaric acid as the source of carbon and urea as N-dopant. The synthesized NCDs possessed multicolor (blue, green and red) fluorescence and excitation wavelength dependent emission behaviour. It was found that the fluorescence intensity of NCDs was quenched with the addition of cysteamine which may be attributed to the formation of non-fluorescent ground state complex. Under optimum condition, the linear response was observed in the range of 10–210 μM and the detection limit was found to be 75.6 nM for sensing the cysteamine. Moreover, the proposed sensing methodology showed high selectivity for cysteamine over a number of interfering metal ions and amino acids. The remarkable biocompatibility of NCDs was investigated in MDA-MB-231 breast cancer cells which impacts its immense potential for diagnostic purposes. The proposed sensing method is thus simple with high sensitivity and excellent selectivity. We expect that this method will become a potential tool for the detection of cysteamine in biological samples.<\/p>\r\n\r\n
Authors: B. N. Prashanth Kumar, Nagaprasad Puvvada, Shashi Rajput, Siddik Sarkar, Madhusudan Kr. Mahto, Murali M. Yallapu, Amita Pathak, Luni Emdad, Swadesh K. Das, Rui L. Reis, S. C. Kundu, Paul B. Fisher and Mahitosh MandalVol: 15 Pages: 2698-2713Journal: Mol. Pharmaceutics Year: 2018 Posted: 25 Jun 2019
Tamoxifen administration enhanced overall disease-free survival and diminished mortality rates in cancer patients. However, patients with breast cancer often fail to respond for tamoxifen therapy due to the development of a drug-resistant phenotype. Functional analysis and molecular studies suggest that protein mutation and dysregulation of survival signaling molecules such as epidermal growth factor receptor, vascular endothelial growth factor receptor 2, and Akt contribute to tamoxifen resistance. Various strategies, including combinatorial therapies, show chemosensitize tamoxifen-resistant cancers. Based on chemotoxicity issues, researchers are actively investigating alternative therapeutic strategies. In the current study, we fabricate a mesoporous silica gold cluster nanodrug delivery system that displays exceptional tumor-targeting capability, thus promoting accretion of drug indices at the tumor site. We employ dual drugs, ZD6474, and epigallocatechin gallate (EGCG) that inhibit EGFR2, VEGFR2, and Akt signaling pathways since changes in these signaling pathways confer tamoxifen resistance in MCF 7 and T-47D cells. Mesoporous silica gold cluster nanodrug delivery of ZD6474 and EGCG sensitize tamoxifen-resistant cells to apoptosis. Western and immune-histochemical analyses confirmed the apoptotic inducing properties of the nanoformulation. Overall, results with these silica gold nanoclusters suggest that they may be a potent nanoformulation against chemoresistant cancers.<\/p>")">
Authors: Madhusudan Kr. Mahto, Dipanjan Samanta, Suraj Konar , Himani Kalita, and Amita PathakVol: 33 Pages: 3906-3916Journal: Journal of Materials Research Year: 2018 Posted: 25 Jun 2019
Herein, we report N, S co-doped carbon dots (NS CDs) as stabilizing and reducing agents for the synthesis of N, S doped carbon dots-Au nanocomposites (NS CDs-Au NCs) through the solution method and explore the catalytic property of the synthesized nanocomposites in the reduction of nitro aromatic compounds (NACs) such as 4-nitrophenol (4-NP), 4-nitroaniline (4-NA), and nitrobenzene (NB). The appraisal of the catalytic efficacy of the NS CDs-Au NCs was premised on real time monitoring of the reduction of NACs using UV-Visible absorption spectroscopy. The apparent rate constants (kapp) of reduction were found to follow the pseudo-first-order kinetics having values of 1.37 × 10−1, 8.9 × 10−2, and 5.35 × 10−2 s−1 for 4-NP, 4-NA, and NB, respectively. The apparent rate constant (1.37 × 10−1 s−1) observed for the reduction of 4-NP by NaBH4 using NS CDs-Au NCs has been found to be one of the highest values reported in the literature so far thereby validating their excellent efficacy as a catalyst.<\/p>")">
Authors: Suraj Konar, Dipanjan Samanta, Subhajit Mandal, Subhayan Das, Madhusudan Kr Mahto, Manisha Shaw, Mahitosh Mandal and Amita PathakVol: 8 Pages: 42361-42373Journal: RSC Advances Year: 2018 Posted: 25 Jun 2019
Nitrogen and sulfur co-doped carbon dots (NSCDs) synthesized through one-pot microwave-assisted pyrolysis of tartaric acid and thioacetamide have been used as a fluorescent probe for the sensitive and selective detection of clinically important organic aldehyde cinnamaldehyde. The as-prepared NSCDs displayed blue fluorescence (∼12% quantum yield), excellent aqueous solubility along with pH and excitation wavelength dependent emission behavior. In comparison to other aldehydes (formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, hexanal, crotonaldehyde and benzaldehyde) the fluorescence intensity of NSCDs was significantly quenched in the presence of cinnamaldehyde and the reduced intensity was linearly proportional to the concentration of cinnamaldehyde in the range of 0–15 mM with a detection limit of 99.0 μM. The fluorescence quenching of NSCDs was mainly attributed to the photo-excited electron transfer between NSCDs and aldehydes which was confirmed by measuring the life-time through time-resolved luminescence spectroscopy, energy levels of NSCDs through cyclic voltammetry (CV) and energy levels of aldehydes by density functional theory (DFT) based analyses. MTT assay of the NSCDs also proved their good biocompatibility and low toxicity towards human fibroblast cells thereby validating their suitability as a biologically relevant fluorescent probe for sensing cinnamaldehyde.<\/p>")">
Authors: Himani Kalita, Pallabi Pal, Santanu Dhara and AmitaPathakVol: 71 Pages: 363-371Journal: Materials Science and Engineering: C Year: 2017 Posted: 25 Jun 2019
Authors: Siddik Sarkar, Suraj Konar, Puvvada Naga Prasad, Shashi Rajput, B. N. Prashanth Kumar, Raj R. Rao, Amita Pathak, Paul B. Fisher, and Mahitosh MandalVol: 33 Pages: 7649-7659Journal: Langmuir Year: 2017 Posted: 25 Jun 2019
The therapeutic index of poorly water-soluble drugs is often hampered due to poor pharmacokinetics, reduced blood retention, and lack of effective drug concentrations in the tumor region. In order to overcome these issues, drugs are often delivered by use of delivery vehicles to provide an enhanced therapeutic index. Gold nanoparticles synthesized in micellar networks of amphiphilic block copolymer (AuNM) provide an efficient nanocarrier for tissue- and site-specific drug delivery owing to their low cytotoxicity and immunogenicity. AuNM is formed by exploiting the properties of both inorganic Au material and an amphiphilic polymer of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (PEG-PPG-PEG). We further functionalized AuNM with the FDA-approved dual tyrosine kinase inhibitor ZD6474 and studied the physicochemical properties of the conjugate ZD6474-AuNM. Both AuNM and ZD6474-AuNM, with a diameter of ∼70 nm, were very stable at physiological pH. Conversely, at an acidic pH of 5.2, a slow sustained-release profile of ZD6474 was evident from AuNM, which could provide a method of facilitating release of the drug in an acidic tumor environment. In vitro, in triple-negative breast cancer cells, ZD6474-AuNM inhibited tumor cell proliferation, migration, and invasion and induced apoptosis. There was no detectable lysis of red blood cells observed when they were treated with AuNM and ZD6474-AuNM, confirming hemocompatibility. To reinforce the possibility of AuNM serving as a delivery vehicle, AuNM was conjugated with the IR680 dye for tracking, and this conjugate was systemically delivered in female nude mice bearing MDA-MB-231 human breast cancer xenografts. Fluorescence signal was retained in the tumor region in a temporal manner as compared to other organs, indicating passive retention of AuNM in the tumor locale. Moreover, delivery of ZD6474-AuNM in nude mice bearing MDA-MB-231 xenografts led to decreased tumor size as compared to the control group. The promising safety, targeting, and therapeutic results of systemic delivery of ZD6474 by AuNM provide an attractive alternative method for treating patients with metastatic breast cancer.<\/p>")">
Authors: Suraj Konar, Shubhatam Sen and Amita PathakVol: 121 Pages: 11437-11448Journal: J. Phys. Chem. B Year: 2017 Posted: 25 Jun 2019
The influence of different morphologies of nanostructures on amyloid fibrillation has been investigated by monitoring the fibrillation of human serum albumin (HSA) in the presence of rod-, sphere-, flower-, and star-shaped copper oxide (CuO) nanostructures. The different morphologies of CuO have been synthesized from an aqueous solution-based precipitation method using various organic acids, viz., acetic acid, citric acid, and tartaric acid. The fibrillation process of HSA has been examined using various biophysical techniques, e.g., Thioflavin T fluorescence, Congo red binding studies through UV spectroscopy, circular dichroism spectroscopy, and fluorescence microscopy. The monolayer protein coverage on the CuO nanostructures has been established through DLS studies, and the well-fitted Langmuir isotherm model has been used to interpret the differential adsorption behavior of HSA molecules on the CuO nanostructures. The nanostar-shaped CuO, by virtue of their higher specific surface area (94.45 m2 g–1), presence of high indexed facets {211} and high positive surface charge potential (+16.2 mV at pH 7.0) was found to show the highest adsorption of the HSA monomers and thus was more competent to inhibit the formation of HSA fibrils compared to the other nanostructures of CuO.<\/p>")">
Authors: H. Kalita, B.N. Prashanth Kumar, S. Tantubay, M. K. Mahto, M. Mandal and A. PathakVol: 60 Pages: 84-91Journal: Materials Science and Engineering: C Year: 2016 Posted: 25 Jun 2019
Authors: Himani Kalita, Shashi Rajput, B. N. Prashanth Kumar, Mahitosh Mandal and Amita PathakVol: 6 Pages: 21285–21292Journal: RSC Advances Year: 2016 Posted: 25 Jun 2019
In the present study, biocompatible and magnetic Fe3<\/small>O4<\/small>@zirconium phosphate core–shell nanoparticles, comprising a magnetic Fe3<\/small>O4<\/small> core and biocompatible zirconium phosphate shell, were prepared for pH-sensitive and magnetically guided drug delivery applications. The formation of the core–shell nanoparticles was affirmed from the XRD and FT-IR studies. TEM analysis revealed proper coverage of the zirconium phosphate shell on the magnetite core, while magnetic studies substantiated the superparamagnetic behavior of the nanoparticles. The suitability of the nanoparticles for intracellular application was validated through the conventional MTT assay, performed on human breast cancer cell lines (MDA-MB-231). The loading-release behavior of the antitumor drug, curcumin, on and from the core–shell nanoparticles respectively were studied by UV-Vis spectroscopy, where the drug-loaded particles showed pH-sensitive release profiles. The nanoformulated curcumin was found to exhibit enhanced cytotoxicity and better bioavailability in contrast to native curcumin.<\/p>")">
Authors: Shubhatam Sen, Suraj Konar, Bodhisatwa Das, Amita Pathak, Santanu Dhara, Swagata Dasgupta and Sunando DasGuptaVol: 6 Pages: 43104–43115Journal: RSC Advances Year: 2016 Posted: 25 Jun 2019
To understand the pharmacokinetics of administered nanomaterials, it is essential to examine the stability and biological activity of proteins by investigating the physicochemical characteristics of the protein–nanoparticle bioconjugate. In this work, the mechanistic detail of the interaction between human serum albumin (HSA) and silver nanoparticles synthesized using nontoxic and biodegradable chitosan as a reducing and stabilizing agent, have been investigated at the nanobio interface. A combination of spectroscopic, calorimetric, and microscopic techniques have been employed to monitor the interaction process. The results illustrate that the chitosan-mediated silver nanoparticles spontaneously bind to HSA without appreciable conformational changes of the protein. Furthermore the potential of the nanoparticles to inhibit the formation of HSA amyloid-like fibrils, in vitro<\/em>, has been analyzed using thioflavin T fluorescence, circular dichroism, fluorescence microscopy, and transmission electron microscopy. The experimental observations indicate that interactions between HSA and chitosan-based silver nanoparticles have led to appreciable reduction in amyloid fibril formation. Additionally, cytotoxicity and hemolytic assays are performed to ensure the biocompatibility of the nanoparticles within the application limit.<\/p>")">
Authors: Himani Kalita and Amita PathakVol: 2 Pages: 68-73Journal: Green Chemistry and Technology Letters, 2(2), 68-73 (2016) Year: 2016 Posted: 22 Dec 2018
The present work reports the preparation of hollow TiO2 nanospheres through sacrificial core templating method where, the sacrificial core of carbon spheres were indigenously synthesized and mixed into the starting ethanolic solution of titanium tetraisopropoxide (TTIP) under ambient condition. The solid obtained on the hydrolysis of TTIP were dried and calcined in air to acquire the hollow nanospheres of TiO2 in anatase phase. The acquired samples were further doped with varying mole % of Mn(II) to invoke magnetism in the material. X-ray diffraction and thermal studies reflected the anatase to rutile phase transformation of TiO2 at 550 °C when the dopant (i.e., Mn) concentration was increased from 0 to 6 mol % (with respect to Ti). The hollow and spherical morphology of the TiO2 nanostructures were confirmed through scanning electron microscopic studies while their ferromagnetic behaviour (at 300 K) was affirmed through SQUID analysis. For intracellular applications, the biocompatibility of the nanospheres was tested through conventional MTT assay, performed on MDA-MB 231 cancer cell lines.<\/p>")">
Authors: Suraj Konar, Himani Kalita, Nagaprasad Puvvada, SangeetaTantubay, Madhusudan Kr.Mahto, Suprakash Biswas and AmitaPathakVol: 336 Pages: 11-22Journal: Journal of Catalysis, 336, 11-22 (2016) Year: 2016 Posted: 22 Dec 2018
Ligand-regulated growth of various morphologies of copper oxide (CuO) nanostructures has been achieved through an aqueous-based chemical precipitation route where the Cu2+ ions were stabilized through complexation with different organic acids (viz. acetic\/citric\/tartaric acid). The rod-, spherical-, star-, and flower-shaped morphologies of the CuO nanostructures, obtained in the presence of the different carboxylic acids, have been characterized using XRD, FTIR, HRTEM, DLS, and zeta potential measurements, while their specific surface areas and the associated band gap energies have been compared. The catalytic performance of the different CuO nanostructures has been affirmed by monitoring the reduction of 4-nitrophenol by NaBH4 in real time using UV–visible absorption spectroscopy. The star-shaped morphologies of CuO have been found to show maximum catalytic activity toward the reduction of 4-nitrophenol in the presence of NaBH4, which can be correlated to their higher specific surface area and positive surface charge and to the presence of a high indexed facet.<\/p>")">
Authors: S. Rajput, N. Puvvada,B. N. P. Kumar, S. Sarkar, S. Konar, R. Bharti, G. Dey, A.. Mazumdar, A. Pathak, P.B. Fisher, M. MandalVol: 12 Pages: 4214-4225Journal: Molecular Pharmaceutics, 12 (12) , 4214–422 (2015) Year: 2015 Posted: 22 Dec 2018
Akt overexpression in cancer causes resistance to traditional chemotherapeutics. Silencing Akt through siRNA provides new therapeutic options; however, poor in vivo<\/em> siRNA pharmacokinetics impede translation. We demonstrate that acidic milieu-sensitive multilamellar gold niosomes (Nio-Au) permit targeted delivery of both Akt-siRNA and thymoquinone (TQ) in tamoxifen-resistant and Akt-overexpressing MCF7 breast cancer cells. Octadecylamine groups of functionalized gold nanoparticles impart cationic attribute to niosomes, stabilized through polyethylene glycol. TQ’s aqueous insolubility renders its encapsulation within hydrophobic core, and negatively charged siRNA binds in hydrophilic region of cationic niosomes. These niosomes were exploited to effectively knockdown Akt, thereby sensitizing cells to TQ. Immunoblot studies revealed enhanced apoptosis by inducing p53 and inhibiting MDM2 expression, which was consistent with in vivo<\/em> xenograft studies. This innovative strategy, using Nio-Au to simultaneously deliver siRNA (devoid of any chemical modification) and therapeutic drug, provides an efficacious approach for treating therapy-resistant cancers with significant translational potential.<\/p>")">
Authors: Sangeeta Tantubay, Sourav K Mukhopadhyay, Himani Kalita, Suraj Konar, Satyahari Dey, Amita Pathak, Panchanan PramanikVol: 17 (6) Pages: 1-18Journal: Journal of Nanoparticle Research, 17 (6) 1-18 (2015) Year: 2015 Posted: 22 Dec 2018
Carboxymethylated chitosan (CMC)-stabilized copper nanoparticles (Cu-NPs) have been synthesized via chemical reduction of copper(II)–CMC complex in aqueous medium by hydrazine under microwave irradiation in ambient atmosphere. Structural morphology, phase, and chemical compositions of CMC-stabilized Cu-NPs (CMC–Cu-NPs) have been analyzed through high-resolution transmission electron microscopy, field emission scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Antifungal and antibacterial activities of CMC–Cu-NPs have been evaluated against Candida tropicalis<\/em> and Escherichia coli<\/em> through agar well diffusion method, broth microdilution assay, live–dead assay, and microscopic observation. Antimicrobial activity of spherical CMC–Cu-NPs (~4–15 nm of diameters) has been observed to be significant for both C. tropicalis<\/em> and E. coli<\/em>. The cytotoxicity study indicates that CMC–Cu-NPs have no significant toxic effect against normal cell line, L929.<\/p>")">
Authors: Nagaprasad Puvvada, Shashi Rajput, B.N. Prashanth Kumar, Siddik Sarkar, Suraj Konar, Keith R. Brunt, Raj R. Rao, Abhijit Mazumdar, Swadesh K. Das, Ranadhir Basu, Paul B. Fisher, Mahitosh Mandal and Amita PathakVol: 5 Pages: 11760Journal: Scientific Reports, 5:11760, 1-15 (2015) Year: 2015 Posted: 22 Dec 2018
Low pH in the tumor micromilieu is a recognized pathological feature of cancer. This attribute of cancerous cells has been targeted herein for the controlled release of chemotherapeutics at the tumour site, while sparing healthy tissues. To this end, pH-sensitive, hollow ZnO-nanocarriers loaded with paclitaxel were synthesized and their efficacy studied in breast cancer in vitro<\/em> and in vivo<\/em>. The nanocarriers were surface functionalized with folate using click-chemistry to improve targeted uptake by the malignant cells that over-express folate-receptors. The nanocarriers released ~75% of the paclitaxel payload within six hours in acidic pH, which was accompanied by switching of fluorescence from blue to green and a 10-fold increase in the fluorescence intensity. The fluorescence-switching phenomenon is due to structural collapse of the nanocarriers in the endolysosome. Energy dispersion X-ray mapping and whole animal fluorescent imaging studies were carried out to show that combined pH and folate-receptor targeting reduces off-target accumulation of the nanocarriers. Further, a dual cell-specific and pH-sensitive nanocarrier greatly improved the efficacy of paclitaxel to regress subcutaneous tumors in vivo<\/em>. These nanocarriers could improve chemotherapy tolerance and increase anti-tumor efficacy, while also providing a novel diagnostic read-out through fluorescent switching that is proportional to drug release in malignant tissues.<\/p>")">
Authors: H Kalita, S Konar, S Tantubay, MK Mahto, A PathakVol: 5 Pages: 901–910Journal: Applied Nanoscience, 1-10 (2015) Year: 2015 Posted: 22 Dec 2018
Mn-doped titania hollow nanospheres were prepared via sacrificial core templating method at room temperature, using carbon spheres as the sacrificial core and template. X-ray diffraction and thermal studies showed the phase transformation of titania from anatase to rutile at temperature as low as 550 °C, when the dopant (i.e., Mn) concentration was increased from 1 to 6 mol % (with respect to Ti). Fourier transform infra red spectroscopic studies have been carried out to determine the surface functional groups, while the spherical and hollow morphology of the titania nanostructures have been confirmed through scanning electron microscopic as well as transmission electron microscopic studies. The chemical composition of the samples has been determined through X-ray photoelectron spectroscopic studies, while their magnetic properties have been studied using superconducting quantum interference device analysis. The biocompatibility and suitability of the nanospheres for intracellular applications has been tested through conventional MTT assay using MDA-MB 231 human breast cancer cell lines.<\/p>")">
Authors: BN Prashanth Kumar, Nagaprasad P, S Rajput, S Sarkar, S K Das, L Emdad, D. Sarkar, P Venkatesan, I. Pal, G. Dey, S. Konar, K R Brunt, Raj R Rao, A. Mazumdar, S C Kundu, A Pathak, P B Fisher, M MandalVol: 3 Pages: 90-101Journal: Journal of Materials Chemistry B,, 3 (1), 90-101. (2015) Year: 2015 Posted: 22 Dec 2018
Single drug therapies for cancer are often suboptimal and may not provide long term clinical benefits. To overcome this obstacle for effective treatment the applications of two or more drugs are preferable. A limitation of multidrug use is the varying pharmacokinetics of different drugs. To overcome these impediments, we designed and synthesized multi-layered polyvinyl alcohol tethered hollow manganese ferrite nanocarriers capable of encapsulating two drugs with unique attributes of sensitivity towards tumor acidic milieu, mono-dispersive, compactness and high encapsulation efficiency. We encapsulated tamoxifen and diosgenin in the peripheral and subsequent inner layers of multilayered nanocarriers. In vitroand in vivo studies evaluated the nanocarrier uptake and retention ability of the tumor through magnetic saturation studies and elucidated the molecular mechanisms mediating drug(s)-induced apoptosis. The acidity of the tumor environment triggers extracellular dissociation of the peripheral coats resulting in release of tamoxifen blocking the estrogen receptor. The partially degraded nanocarriers localize intracellularly through endosomal escape and release diosgenin. Nanocarrier treatment reduced the cellular levels of Bcl2 and p53, while increasing the levels of Bim. This delivery system successfully embodies the sequential release of drugs and may provide a therapeutic strategy for sequentially affecting multiple targets in advanced cancers.<\/p>")">
Authors: S Sen, S Konar, A Pathak, S Dasgupta, S DasGuptaVol: 118 Pages: 11667?11676Journal: The Journal of Physical Chemistry B,, 118 (40), 11667-116 (2014) Year: 2014 Posted: 22 Dec 2018
Pathogenesis of amyloid-related diseases is related to nonnative folding of proteins with the formation of insoluble deposits in the extracellular space of various tissues. Having the unique properties of small size, large surface area, biodegradability, and relative nontoxicity, magnetic nanoparticles have drawn a lot of attention in biomedical applications. Herein, we demonstrate the effect of bare and differently functionalized magnetic MnFe2O4 nanoparticles on fibrillation of human serum albumin in vitro. The process has been monitored using Thioflavin T fluorescence, Congo red binding assay, circular dichroism, fluorescence microscopy, and transmission electron microscopy. From our experimental results, amine functionalized MnFe2O4 nanoparticles are found to inhibit formation of fibrils more effectively than bare ones, while carboxylated nanoparticles do not have a significant effect on fibrillation. This study has explored the prospects of using specific magnetic nanoparticles with appropriate modification to control self-assembly of proteins and may act as a precursor in therapeutic applications.<\/p>")">
Photoresponsive coumarin-tethered multifunctional magnetic nanoparticles for release of anticancer drug
Authors: S. Karthik, Nagaprasad Puvvada, B. N. Prashanth Kumar, Shashi Rajput, Amita Pathak, Mahitosh Mandal, and N. D. Pradeep Singh Journal: ACS Appl. Mater. Interfaces, 5(11), 5232-5238 (2013) Year: 2013 Posted: 22 Dec 2018
Exploring the fluorescence switching phenomenon of curcumin encapsulated niosomes: in vitro real time monitoring of curcumin release to cancer cells
Authors: Nagaprasad Puvvada, Shashi Rajput, B. N. Prashanth Kumar, Mahitosh Mandal and Amita Pathak Journal: RSC Advances, 3, 2553-2557 (2013) Year: 2013 Posted: 22 Dec 2018
The Growth of Bismuth Sulfide Nanorods from Spherical-Shaped Amorphous Precursor Particles under Hydrothermal Condition
Authors: Pravas Kumar Panigrahi and Amita Pathak Journal: Journal of Nanoparticles, Volume 2013, Article (2013) Year: 2013 Posted: 22 Dec 2018
Synthesis of biocompatible multicolor luminescent carbon dots for bioimaging applications
Authors: Nagaprasad Puvvada, B N Prashanth Kumar, Suraj Konar, Himani Kalita, Mahitosh Mandal and Amita Pathak Journal: SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS, 13, 045008 (2012) Year: 2012 Posted: 22 Dec 2018
Effect of temperature on morphology of triethanolamine-assisted synthesized hydroxyapatite nanoparticles
Authors: Nagaprasad Puvvada, Pravas Kumar Panigrahi, Himani Kalita, Keka R. Chakraborty, Amita Pathak Journal: Applied Nanoscience, Vol 2 (2012) Year: 2012 Posted: 22 Dec 2018
Aqueous route for the synthesis of magnetite nanoparticles under atmospheric air: functionalization of surface with fluorescence marker
Authors: Nagaprasad Puvvada, Dhritabrata Mandal, Pravas Kumar Panigrahi and Amita Pathak Journal: Toxicology Research, Vol 1, pp 196 (2012) Year: 2012 Posted: 22 Dec 2018
Shape dependent peroxidase mimetic activity towards oxidation of Pyrogallol by H2O2
Authors: Nagaprasad Puvvada, Pravas Kumar Panigrahi, Dhritabrata Mandal and Amita PathakJournal: RSC Advances, 2, 3270-3273 (2012) Year: 2012 Posted: 22 Dec 2018
A novel route for the synthesis of nanotubes and fullerene-like nanostructures of molybdenum disulfide
Authors: Pravas Kumar Panigrahi and Amita Pathak Journal: Materials Research Bulletin, 46 (12) 2240-224 (2011) Year: 2011 Posted: 22 Dec 2018
The potential of celecoxib-loaded hydroxyapatite-chitosan nanocomposite for the treatment of colon cancer
Authors: P. Venkatesan, Nagaprasad Puvvada, Rupesh Dash, B.N. Prashanth Kumar, Devanand Sarkar, Belal Azab, Amita Pathak, Subhas C. Kundu, Paul B. Fisher, Mahitosh Mandal Journal: Biomaterials, 32 3794-3806 (2011) Year: 2011 Posted: 22 Dec 2018
Authors: Biswas S. K., A. Sarkar, A. Pathak, and P. PramanikVol: 81 Pages: 1607-1612Journal: Talanta, 81 1607–1612 (2010) Year: 2010 Posted: 22 Dec 2018
In the present article, the gas sensing behaviour of nanocrystalline CuGa2O4 towards H2, liquefied petroleum gas (LPG) and NH3 has been reported for the first time. Nanocrystalline powders of CuGa2O4 having average particle sizes in the range of 30–60 nm have been prepared through thermal decomposition of an aqueous precursor solution comprising copper nitrate, gallium nitrate and triethanol amine (TEA), followed by calcination at 750 °C for 2 h. The synthesized nanocrystalline CuGa2O4 powders have been characterised through X-ray diffraction (XRD), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM) study, energy dispersive X-ray (EDX) analysis and BET (Brunauer–Emmett–Teller) surface area measurement. The synthesized CuGa2O4 having spinel structure with specific surface area of 40 m2\/g exhibits maximum sensitivity towards H2, LPG, and NH3 at 350 °C.<\/p>")">
Room temperature synthesis of highly hemocompatible hydroxyapatite, study of their physical properties and spectroscopic correlation of particle size
Authors: Nagaprasad Puvvada, Pravas Kumar Panigrahi and Amita PathakVol: 2 Pages: 2631-2638Journal: Nanoscale, 2 2631–2638 (2010) Year: 2010 Posted: 22 Dec 2018
Microwave-assisted synthesis of WS2 nanowires through tetrathiotungstate precursors
Authors: Pravas Kumar Panigrahi and Amita Pathak Journal: Science and Technology of Advanced Materials, 9, 045008 (2008) Year: 2008 Posted: 22 Dec 2018
Chemical synthesis of environment-friendly nanosized yellow titanate pigments
Authors: Soumya Kanti Biswas, Debasis Dhak, Amita Pathak, Panchanan Pramanik Journal: Material Research Bulletin, 43, 665–675, (2008) Year: 2008 Posted: 22 Dec 2018
Codoped Cr and W rutile nanosized powders obtained by pyrolysis of triethanolamine complexes
Authors: Soumya K. Biswas, A. Pathak, N. K. Pramanik, D. Dhak, P. Pramanik Journal: Ceramic International, 34 (8), 1875-1883 (2008) Year: 2008 Posted: 22 Dec 2018
Synthesis of Nanocrystalline KTiOPO4 Powder by Chemical Method
Authors: Soumya Kanti Biswas, Amita Pathak, Panchanan PramanikJournal: Journal of the American Ceramic Society, 90(4), 1071-1076 (2007) Year: 2007 Posted: 22 Dec 2018
Chemical Synthesis of Nanocrystalline Strontium Bismuth Tantalate (SBT) Powders Using Tantalum Tartarate complex
Authors: A.B. Panda, A. Pathak, P. PramanikJournal: Journal of American Ceramic Society, 89 [2] 737–739 (2006) Year: 2006 Posted: 22 Dec 2018
Preparation of Nanosized Mixed-Oxide Powders using Triethanolamine / Diethanolamine as Complexing Agent
Authors: A. Pathak, S. Mohapatra, S. Mohapatra, S.K. Biswas, D. Dhak, A. Tarafdar, P. Pramanik Journal: American Ceramic Society Bulletin, 83 (8), 9301-9306 (2004) Year: 2004 Posted: 22 Dec 2018
A giant vesicle forming single tailed chiral surfactant for enantioseparation by micellar electrokinetic chromatography
Authors: A. Mohanty and J. Dey Journal: J. Chem. Soc. Chem. Comm., 1384-1385 PP (2003) Year: 2003 Posted: 22 Dec 2018
Solvent-induced switching between static and dynamic fluorescence quenching of N, S Co-doped carbon dots in sensing of Crotonaldehyde: A detailed systematic study
Authors: Manisha Shaw, Dipanjan Samanta, Md Abdus Salam Shaik, Angana Bhattacharya, Rajarshi Basu, Imran Mondal, Amita PathakVol: 137 Pages: Journal: Optical Materials Year: Posted: 24 Feb 2023
.png)
.jpeg)
