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Dr. Sujoy Das

Central leather research Institute, BIO-PRODUCTS LAB, Faculty Member

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Our current research focuses in the Infectious Diseases and Immunology Division of CSIR-IICB on exploitation of biological materials in synthesis of novel nanomaterial synthesis and their application in biomedical science. The lab pursues a broad range of research interests that include biomimetics and bioinspired nanomaterial synthesis, understanding the fundamental mechanism of bioinspired nanomaterial synthesis, design of multi functional nanomaterials, utilization of bio and nanomaterials in biomedicine.
Phone: +914424437133
Address: CSIR-Central Leather Research Institute (CLRI), Adyar, Chennai 600020, India
http://www.clri.org/WriteReadData/Biodata/DrSujoy.html

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Loughborough University

School of the Art Institute of Chicago

Stéphane Bordas

Université du Luxembourg

Jayjit Majumdar

University of Kalyani

King Saud University

Prof. Nagwa Mohamed A . Aref

Ain Shams University

PROF. OM PRAKASH SINHA

Amity University

Kaitlyn Dykstra

University of North Carolina at Chapel Hill

South East Technological University

Christos Kanellopoulos

Université de Genève

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Books by Dr. Sujoy Das

Bioinspired Metal Nanoparticle: Synthesis, Properties and Application

The book "Nanomaterials" includes all aspects of metal-oxide nano-structures, nano-composites, an... more The book "Nanomaterials" includes all aspects of metal-oxide nano-structures, nano-composites, and polymer materials instigating with materials survey and preparations, growth and characterizations, processing and fabrications, developments and potential applications. These topics have utilized innovative methods of preparation, improvement, and continuous changes in multidimensional ways. The innovative frontiers are branching out from time to time to advanced nanotechnology. It is an important booklet for scientific organizations, governmental research-centers, academic libraries, and the overall research and development of nano-materials in general. It has been created for widespread audience with diverse backgrounds and education.

Papers by Dr. Sujoy Das

Gallic Acid and Gallates in Human Health and Disease: Do Mitochondria Hold the Key to Success?

Molecular Nutrition & Food Research, 2017

Gallic acid and gallate esters are widely used as dietary supplements or additives with clinical ... more Gallic acid and gallate esters are widely used as dietary supplements or additives with clinical significances. Over the last few decades, a large number of publications have been reported stating the antioxidative, antiapoptotic, cardioprotective, neuroprotective, and anticancer properties of gallic acid and gallates, and mostly demonstrated their antioxidative or prooxidative properties influencing the reactive oxygen species (ROS) signaling networks. However, very little focus has been paid to clinical trials, and this restricted their use as a prescribed preventative supplement. Since mitochondria are the principal organelles responsible for ROS generation, we reviewed the existing literature of mitochondria‐specific effects of gallates including ROS production, respiration, mitochondrial biogenesis, apoptosis, and the physico‐chemical parameters affecting the outcome of gallate supplementation to various health scenarios such as cardiovascular diseases, neurodegeneration, hepat...

Antibacterial and Antibiofouling Activities of Antimicrobial Peptide-Functionalized GrapheneSilver Nanocomposites for the Inhibition and Disruption of Staphylococcus aureus Biofilms

Owing to the emergence of antibiotic-resistant strains, bacterial infection and biofilm formation... more Owing to the emergence of antibiotic-resistant strains, bacterial infection and biofilm formation are growing concerns in healthcare management. Herein, we report an eco-benign strategy for the synthesis and functionalization of graphene-silver (rGOAg) nanocomposites with an antimicrobial peptide (AMP) for the treatment of Staphylococcus aureus infection. The synthesis of rGOAg nanocomposites was carried out by simple microwave reduction, and the as-synthesized rGOAg was covalently functionalized with an AMP. As a natural AMP, poly-l-lysine (PLL) functionalization of rGOAg enhanced the antibacterial efficacy and target specificity against the S. aureus biofilm. The robust bactericidal efficiency and biofilm disruption by AMP-functionalized rGOAg (designated as GAAP) occurred through the "contact-kill-release" mode of action, where the electrostatic interaction with bacterial cells together with intracellular ROS generation induced physical disruption to the cell membrane. The internalization of GAAP into the cytoplasm through the damaged cell membrane caused an outburst of intracellular proteins and DNA. Crystal violet staining along with fluorescence and confocal microscopic images showed an effective inhibition and disruption of the S. aureus biofilm upon treatment with GAAP. PLL functionalization also prevented the dissolution of Ag+ ions and thereby minimized the in vitro toxicity of GAAP to the 3 T6 fibroblast and human red blood cells. The ex vivo rat skin disinfection model further demonstrated the potency of GAAP in eliminating the biofilm formation and disruption of the S. aureus biofilm. The obtained results demonstrated a general approach for designing a functional nanocomposite material to disrupt the mature biofilm and provided a promising strategy for treating bacterial infection.

Incorporations of gold, silver and carbon nanomaterials to kombucha-derived bacterial cellulose: Development of antibacterial leather-like materials

Journal of the Indian Chemical Society, 2022

Rational design of antimicrobial peptide conjugated graphene-silver nanoparticle loaded chitosan wound dressing

International Journal of Biological Macromolecules

Wound dressing with poor antibacterial properties, the tendency to adhere to the wound site, poor... more Wound dressing with poor antibacterial properties, the tendency to adhere to the wound site, poor mechanical strength, and lack of porosity and flexibility are the major cause of blood loss, delayed wound repair, and sometimes causes death during the trauma or injury. In such cases, hydrogel-based antibacterial wound dressing would be a boon to the existing dressing as the moist environment will maintain the cooling temperate and proper exchange of atmosphere around the wound. In the present study, the multifunctional graphene with silver and ε-Poly-L-lysine reinforced into the chitosan matrix (CGAPL) was prepared as a nanobiocomposite wound dressing. The contact angle measurement depicted the hydrophilic property of CGAPL nanobiocomposite dressing (water contact angle 42 •), while the mechanical property was 78.9 MPa. The antibacterial and cell infiltration study showed the antimicrobial property of CGAPL nanobiocomposite wound dressing. It also demonstrated no cytotoxicity to the L929 fibroblast cells. Chorioallantoic Membrane (CAM) assay showed the pro-angiogenic potential of CGAPL nanobiocomposite wound dressing. In-vitro scratch wound assay confirmed the migration of cells and increased cell adhesion and proliferation within 18 h of culture on the surface of CGAPL nanobiocomposite dressing. Later, the in-vivo study in the Wistar rat model showed that CGAPL nanobiocomposite dressing significantly enhanced the wound healing process as compared to the commercially available wound dressing Tegaderm (p-value &lt;0.01) and Fibroheal@Ag (p-value &lt;0.005) and obtained complete wound closure in 14 days. Histology study further confirmed the complete healing process, re-epithelization, and thick epidermis tissue formation. The proposed CGAPL nanobiocomposite wound dressing thus offers a novel wound dressing material with an efficient and faster wound healing property.

Nanotechnology based therapeutic approaches: an advanced strategy to target the biofilm of ESKAPE pathogens

Materials Advances

Nanotechnology based therapeutic approaches are a promising strategy to target biofilm-related in... more

Rationally designed Shewanella oneidensis Biofilm Toilored Graphene-Magnetite Hybrid Nanobiocomposite as Reusable Living Functional Nanomaterial for Effective Removal of Trivalent Chromium

Environmental Pollution, 2021

Sustainable treatment of wastewater containing trivalent chromium (Cr3+) remains a significant ch... more Sustainable treatment of wastewater containing trivalent chromium (Cr3+) remains a significant challenge owing to the several limitations of the existing methodologies. Herein, combination of biosynthesis and Response Surface Methodology (RSM) for the fabrication and optimization of Shewanella oneidensis biofilm functionalized graphene-magnetite (GrM) nanobiocomposite was adopted as a 'living functional nanomaterial' (viz. S-GrM) for effective removal of Cr3+ ions from aqueous solution. In the biosynthetic process, S. oneidensis cells reduced the GO-akaganeite complex and adhered on the as-synthesized GrM nanocomposite to form S-GrM hybrid-nanobiocomposite. The process parameters for fabrication of S-GrM hybrid-nanobiocomposite was optimized by RSM based on four responses of easy magnetic separation, biofilm formation along with protein, and carbohydrate contents in extracellular polymeric substances (EPS). The morphology and chemical composition of S-GrM hybrid-nanobiocomposite were investigated using various spectroscopic and microscopic analyses and subsequently explored for removal of Cr3+ ions. The hybrid-nanobiocomposite effectively removed 304.64 ± 14.02 mg/g of Cr3+ at pH 7.0 and 30 °C, which is found to be very high compared to the previously reported values. The high surface area of graphene, biofilm biomass of S. oneidensis and plenty of functional groups provided a unique structure to the S-GrM hybrid-nanobiocomposite for efficient removal of Cr3+ through synergistic interaction. The FTIR and zeta potential studies confirmed that electrostatic and chelation/complexation reaction played key roles in the adsorption process. The fabrication of S-GrM nanobiocomposite thus creates a novel hybrid 'living functional nanomaterial' for low cost, recyclable, and sustainable removal of Cr3+ from wastewater.

Green Synthesis of Nanomaterials with Special Reference to Environmental and Biomedical Applications

Current Science, 2015

Environmental benign bioinspired and/or biomimetic synthetic process of metal nanoparticles have ... more Environmental benign bioinspired and/or biomimetic synthetic process of metal nanoparticles have been developed for water purification and biomedical applications. In the synthetic process, the biomolecules acted as shape directing agent determining the crystal structure of the nanoparticles and also control the surface properties of the nanomaterials.

Microcapsules from diverse polyfunctional materials: synergistic interactions for a sharp response to pH changes

New Journal of Chemistry, 2018

Responsive microcapsules with strong synergistic interactions were prepared using a copolymer, si... more

Biomaterial Functionalized Graphene-Magnetite Nanocomposite: A Novel Approach for Simultaneous Removal of Anionic Dyes and Heavy-Metal Ions

ACS Sustainable Chemistry & Engineering, 2018

Despite of immense application potential of graphene in wastewater treatment, the colloidal stabi... more Despite of immense application potential of graphene in wastewater treatment, the colloidal stability, aggregation and recyclability remains a major challenge. To address this issue, we report biomaterial functionalized graphene-magnetite (Bio-GM) nanocomposite as a novel recyclable material for treatment of wastewater containing dyes and heavy metal. The integration of biomaterial including living cells of Shewanella oneidensis with graphene-magnetite nanocomposite was characterized through UV-vis, FTIR, FESEM and fluorescent microscopic studies. The contact angle measurement depicted the hydrophilic property (water contact-angle 27.93), while VSM result demonstrated super paramagnetic behavior of the nanocomposite with saturation magnetization value of 30.2 emu/g. The Bio-GM nanocomposite exhibited excellent adsorption capacity towards dyes and Cr 6+ in both single and multicomponent system with removal capacity of 189.63 ± 7.11, and 222.2 ± 8.64 mg/g of dyes and Cr +6 , respectively, suggesting selective binding capacity and high adsorption efficiency of Bio-GM nanocomposite. In the adsorption coupled redox reaction, the Cr +6 was reduced to Cr +3 through biocatalytic activity of Bio-GM nanocomposite. The nanocomposite could be easily regenerated and reused for multiple cycles of adsorption-desorption studies without release of graphene and magnetite, and thus eliminating the potential hazardous risk of nanomaterial to the environment. The proposed biomaterial functionalized graphene-magnetite nanocomposite thus offers a novel way for sustainable, affordable and efficient removal of coexisting toxic pollutants of dyes and heavy metal.

Metal Nanoparticle Loaded Magnetic-Chitosan Microsphere: Water Dispersible and Easily Separable Hybrid Metal Nano-biomaterial for Catalytic Applications

ACS Sustainable Chemistry & Engineering, 2017

We report a green synthesis of magnetically separable hybrid metal nano-biomaterial as water disp... more We report a green synthesis of magnetically separable hybrid metal nano-biomaterial as water dispersible and recyclable catalysts. The hybrid nano-biomaterial was prepared in three step process. The magnetic nanoparticles were initially synthesized by biomineralization process and coated with chitosan followed by binding and reduction of metal ions, which led to the formation of magnetically separable hybrid nano-biomaterial (Fe 3 O 4 @Ch-MNPs, M=Au and Pd). The chemical composition, morphology, thermal stability and magnetic behaviour of the hybrid nano-biomaterial were characterized with Zeta potential, FTIR, XPS, XRD, VSM, FESEM, and TEM analysis. The FESEM measurement demonstrated formation of highly dispersed Au and PdNPs on the surface of nano-biomaterial, while TGA and VSM analyses indicated high thermal stability and superparamagnetic behaviour of the hybrid nano-biomaterial. The XPS studies revealed formation of pure metallic nanoparticles on the surface of the hybrid nano-biomaterial. The as-synthesised hybrid nano-biomaterial were tested for several model reactions such as photocatalytic reduction of dye, hydrogenation of p-nitrophenol and Suzuki coupling reaction at ambient temperature and in aqueous solution. The catalytic efficiencies varied with the type of MNPs and Fe 3 O 4 @Ch-PdNPs exhibited superior catalytic activities in all chemical reactions. In addition the hybrid nano-biomaterial demonstrated excellent recyclability and reusability without significant loss of catalytic activities. Furthermore, leaching of metal ions was not detected during catalytic reaction confirming high stability and low environmental impact of the as-synthesised hybrid nano-biomaterial. We believe that our result will help to synthesize easily separable hybrid nano-biomaterial as heterogeneous catalyst through cost effective and eco-benign synthetic route for development of environmental sustainable nanotechnology.

Cationic Surfactant (CTAC) Assisted Synthesis of Silver Nanoparticles with Controlled Size: Optical, Morphological and Bactericidal Studies

Journal of Nanoengineering and Nanomanufacturing, 2015

Total Elimination of Polluting Chrome Shavings, Chrome, and Dye Exhaust Liquors of Tannery by a Method Using Keratin Hydrolysate

ACS Sustainable Chemistry & Engineering, 2015

ABSTRACT The solid and liquid waste management of tanneries has become a serious problem in the l... more ABSTRACT The solid and liquid waste management of tanneries has become a serious problem in the leather industry. In this study we have attempted and succeeded in eliminating these pollutants by a novel method, which has not been done anywhere so far. Keratin hydrolysate (KH) from poultry feathers have been utilized along with chrome shavings (CS) for total elimination of the polluting solid and liquid wastes in a tannery. In this process 100% fixation of the Cr from the chrome exhaust liquor and the dye from the dye exhaust liquor is achieved by the reactions of CS with KH. The infrared spectra of the different stages of CS confirm the fixation of Cr in the chrome shavings-keratin hydrolysate (CSKH) complex. In this work, apart from elimination of tannery pollutants, a leather-like flexible sheet is obtained that can be used in the footwear and leather goods industry. In the SEM evaluation the surface morphology of the product exhibits smoothness because of the incorporation of polyvinyl alcohol and ethylene glycol. The above findings will open new avenues for further research in solid and liquid waste management of tannery effluents.

Antimicrobial behavior of biosynthesized silica-silver nanocomposite for water disinfection: A mechanistic perspective

Journal of hazardous materials, Jan 24, 2015

The biosynthesis of nano-silica silver nanocomposite (NSAgNC) and it is as antibacterial effect o... more The biosynthesis of nano-silica silver nanocomposite (NSAgNC) and it is as antibacterial effect on gram-negative bacteria viz.Escherichia coli and Pseudomonas aeruginosa has been investigated for disinfection of water. The as-synthesized NSAgNC exhibited antibacterial activity in a dose dependent manner and ∼99.9% of E. coli and P. aeruginosa were killed at a concentration of 1.5mg/mL of NSAgNC (5.1wt% Ag) within 5h. The NSAgNC showed similar antibacterial activities both in oxic and anoxic conditions. The results further demonstrated that NSAgNC exhibited reactive oxygen species (ROS) independent "particle specific" antibacterial activity through multiple steps in absence of leached out Ag(+) ions. The initial binding of NSAgNC on the cell wall caused loss of cell membrane integrity and leakage of cytoplasmic materials. Inhibition of respiratory chain dehydrogenase by NSAgNC caused metabolic inactivation of the cells and affecting the cell viability. Genomic and proteomic...

Fabrication of Non-toxic reduced Graphene Oxide Protein Nano-framework as Sustained Antimicrobial Coating for Biomedical Application

ACS applied materials & interfaces, Jan 20, 2017

Bacterial colonization on medical devices is a major concern in the healthcare industry. In the p... more Bacterial colonization on medical devices is a major concern in the healthcare industry. In the present study we report synthesis of environmental sustainable reduced graphene oxide (rGO) at large scale through biosynthetic route and its potential application for antibacterial coating on medical devices. HRTEM image depicts formation of graphene nanosheet, while DLS and ζ potential studies reveal that in aqueous medium the average hydrodynamic size and surface charge of rGO are 4410 ± 116 nm and -25.2 ± 3.2 mV, respectively. The Raman, FTIR and XPS data suggest in-situ conjugation of protein with rGO. The as-synthesized rGO protein nano-framework exhibits dose-dependent antibacterial activity and potential of killing of 94% of Escherichia coli when treated with 80 μg/mL of rGO for 4 h. The hemolytic and cytotoxicity studies demonstrate that rGO protein nano-framework is highly biocompatible at the same concentration showing significant antimicrobial properties. The rGO coated on gla...

“Click” polymerization on a self-assembled monolayer: a convenient approach to functionalize various surfaces with polytriazoles

Chemical Communications, 2012

Bioinspired Metal Nanoparticle: Synthesis, Properties and Application

Nanomaterials, 2011

A green chemical approach for the synthesis of gold nanoparticles: characterization and mechanistic aspect

Reviews in Environmental Science and Bio/Technology, 2010

This IRCSET-EMPOWER (Irish Research Council for Science, Engineering and Technology Postdoctoral ... more This IRCSET-EMPOWER (Irish Research Council for Science, Engineering and Technology Postdoctoral Research Grant) project aims to improve current methodology for the synthesis of metal nanoparticles (NPs). The development of efficient methodology for metal nanomaterials synthesis is an economical and environmental challenge. While the current methods for NPs synthesis are often energy-intensive and involve toxic chemicals, NPs biosynthesis can be carried on at circumneutral pH and mild temperature, resulting in low cost and environmental impact. Nanomaterial biosynthesis has been already observed in magnetotactic bacteria, diatoms, and S-layer bacteria, however, controlled NPs biosynthesis is a relatively new area of research with considerable potential for development. A thorough understanding of the biochemical mechanism involved in NPs biosynthesis is needed, before biosynthetic methods can be economically competitive. The analysis and identification of active species in the nucleation and growth of metal NPs is a daunting task, due to the complexity of the microbial system. This project work focuses on the controlled biosynthesis of gold NPs by fungal microorganisms and aims to determine the biochemical mechanism involved in nucleation and growth of the particles.

Adsorption Behavior of Rhodamine B on Rhizopus oryzae Biomass

Langmuir, 2006

The removal of a carcinogenic dye rhodamine B (C. I. 45170) from wastewater by biomass of differe... more The removal of a carcinogenic dye rhodamine B (C. I. 45170) from wastewater by biomass of different moulds and yeasts is described. Among all of the fungal species tested, the biomass of Rhizopus oryzae MTCC 262 is found to be the most effective. Dye adsorption reaches maximum with the biomass harvested from the early stationary phase of growth. The optimum temperature and pH for adsorption are observed to be 40°C and 7.0, respectively. The adsorption rate is very fast initially and attains equilibrium after 5 h. The adsorption isotherm follows the Langmuir isotherm model satisfactorily within the studied dye concentration range. Of the different metabolic inhibitors tested, 2,4-ditrophenol (DNP) and N,N′-dicyclohexylcarbodiimide (DCCD) decrease dye adsorption by ∼30% suggesting the role of energy metabolism in the process. Spectrophotometric study indicates that the removal of rhodamine B by R. oryzae biomass involves an adsorption process. Scanning (SEM) and transmission (TEM) electron microscopic investigations have been carried out to understand the probable mechanism of the dye-biomass interaction.

A study on lead adsorption by Mucor rouxii biomass

Desalination, 2010

Removal of lead from its aqueous solutions by adsorption on different biomasses was studied. Muco... more Removal of lead from its aqueous solutions by adsorption on different biomasses was studied. Mucor rouxii biomass (MRB) had been found to be the most efficient in this respect and removed more than 90% of lead from its aqueous solution. Adsorption of lead by the biomass was dependent on pH and temperature. Maximum sorption was noted at the pH range of 5.0–6.0 and an increase in temperature above 30° C resulted in the decrease in adsorption indicating the exothermic nature of the process. The adsorption process was ...

Bioinspired Metal Nanoparticle: Synthesis, Properties and Application

The book "Nanomaterials" includes all aspects of metal-oxide nano-structures, nano-composites, an... more The book "Nanomaterials" includes all aspects of metal-oxide nano-structures, nano-composites, and polymer materials instigating with materials survey and preparations, growth and characterizations, processing and fabrications, developments and potential applications. These topics have utilized innovative methods of preparation, improvement, and continuous changes in multidimensional ways. The innovative frontiers are branching out from time to time to advanced nanotechnology. It is an important booklet for scientific organizations, governmental research-centers, academic libraries, and the overall research and development of nano-materials in general. It has been created for widespread audience with diverse backgrounds and education.

Gallic Acid and Gallates in Human Health and Disease: Do Mitochondria Hold the Key to Success?

Molecular Nutrition & Food Research, 2017

Gallic acid and gallate esters are widely used as dietary supplements or additives with clinical ... more Gallic acid and gallate esters are widely used as dietary supplements or additives with clinical significances. Over the last few decades, a large number of publications have been reported stating the antioxidative, antiapoptotic, cardioprotective, neuroprotective, and anticancer properties of gallic acid and gallates, and mostly demonstrated their antioxidative or prooxidative properties influencing the reactive oxygen species (ROS) signaling networks. However, very little focus has been paid to clinical trials, and this restricted their use as a prescribed preventative supplement. Since mitochondria are the principal organelles responsible for ROS generation, we reviewed the existing literature of mitochondria‐specific effects of gallates including ROS production, respiration, mitochondrial biogenesis, apoptosis, and the physico‐chemical parameters affecting the outcome of gallate supplementation to various health scenarios such as cardiovascular diseases, neurodegeneration, hepat...

Antibacterial and Antibiofouling Activities of Antimicrobial Peptide-Functionalized GrapheneSilver Nanocomposites for the Inhibition and Disruption of Staphylococcus aureus Biofilms

Owing to the emergence of antibiotic-resistant strains, bacterial infection and biofilm formation... more Owing to the emergence of antibiotic-resistant strains, bacterial infection and biofilm formation are growing concerns in healthcare management. Herein, we report an eco-benign strategy for the synthesis and functionalization of graphene-silver (rGOAg) nanocomposites with an antimicrobial peptide (AMP) for the treatment of Staphylococcus aureus infection. The synthesis of rGOAg nanocomposites was carried out by simple microwave reduction, and the as-synthesized rGOAg was covalently functionalized with an AMP. As a natural AMP, poly-l-lysine (PLL) functionalization of rGOAg enhanced the antibacterial efficacy and target specificity against the S. aureus biofilm. The robust bactericidal efficiency and biofilm disruption by AMP-functionalized rGOAg (designated as GAAP) occurred through the "contact-kill-release" mode of action, where the electrostatic interaction with bacterial cells together with intracellular ROS generation induced physical disruption to the cell membrane. The internalization of GAAP into the cytoplasm through the damaged cell membrane caused an outburst of intracellular proteins and DNA. Crystal violet staining along with fluorescence and confocal microscopic images showed an effective inhibition and disruption of the S. aureus biofilm upon treatment with GAAP. PLL functionalization also prevented the dissolution of Ag+ ions and thereby minimized the in vitro toxicity of GAAP to the 3 T6 fibroblast and human red blood cells. The ex vivo rat skin disinfection model further demonstrated the potency of GAAP in eliminating the biofilm formation and disruption of the S. aureus biofilm. The obtained results demonstrated a general approach for designing a functional nanocomposite material to disrupt the mature biofilm and provided a promising strategy for treating bacterial infection.

Incorporations of gold, silver and carbon nanomaterials to kombucha-derived bacterial cellulose: Development of antibacterial leather-like materials

Journal of the Indian Chemical Society, 2022

Rational design of antimicrobial peptide conjugated graphene-silver nanoparticle loaded chitosan wound dressing

International Journal of Biological Macromolecules

Wound dressing with poor antibacterial properties, the tendency to adhere to the wound site, poor... more Wound dressing with poor antibacterial properties, the tendency to adhere to the wound site, poor mechanical strength, and lack of porosity and flexibility are the major cause of blood loss, delayed wound repair, and sometimes causes death during the trauma or injury. In such cases, hydrogel-based antibacterial wound dressing would be a boon to the existing dressing as the moist environment will maintain the cooling temperate and proper exchange of atmosphere around the wound. In the present study, the multifunctional graphene with silver and ε-Poly-L-lysine reinforced into the chitosan matrix (CGAPL) was prepared as a nanobiocomposite wound dressing. The contact angle measurement depicted the hydrophilic property of CGAPL nanobiocomposite dressing (water contact angle 42 •), while the mechanical property was 78.9 MPa. The antibacterial and cell infiltration study showed the antimicrobial property of CGAPL nanobiocomposite wound dressing. It also demonstrated no cytotoxicity to the L929 fibroblast cells. Chorioallantoic Membrane (CAM) assay showed the pro-angiogenic potential of CGAPL nanobiocomposite wound dressing. In-vitro scratch wound assay confirmed the migration of cells and increased cell adhesion and proliferation within 18 h of culture on the surface of CGAPL nanobiocomposite dressing. Later, the in-vivo study in the Wistar rat model showed that CGAPL nanobiocomposite dressing significantly enhanced the wound healing process as compared to the commercially available wound dressing Tegaderm (p-value &lt;0.01) and Fibroheal@Ag (p-value &lt;0.005) and obtained complete wound closure in 14 days. Histology study further confirmed the complete healing process, re-epithelization, and thick epidermis tissue formation. The proposed CGAPL nanobiocomposite wound dressing thus offers a novel wound dressing material with an efficient and faster wound healing property.

Nanotechnology based therapeutic approaches: an advanced strategy to target the biofilm of ESKAPE pathogens

Materials Advances

Nanotechnology based therapeutic approaches are a promising strategy to target biofilm-related in... more

Rationally designed Shewanella oneidensis Biofilm Toilored Graphene-Magnetite Hybrid Nanobiocomposite as Reusable Living Functional Nanomaterial for Effective Removal of Trivalent Chromium

Environmental Pollution, 2021

Sustainable treatment of wastewater containing trivalent chromium (Cr3+) remains a significant ch... more Sustainable treatment of wastewater containing trivalent chromium (Cr3+) remains a significant challenge owing to the several limitations of the existing methodologies. Herein, combination of biosynthesis and Response Surface Methodology (RSM) for the fabrication and optimization of Shewanella oneidensis biofilm functionalized graphene-magnetite (GrM) nanobiocomposite was adopted as a 'living functional nanomaterial' (viz. S-GrM) for effective removal of Cr3+ ions from aqueous solution. In the biosynthetic process, S. oneidensis cells reduced the GO-akaganeite complex and adhered on the as-synthesized GrM nanocomposite to form S-GrM hybrid-nanobiocomposite. The process parameters for fabrication of S-GrM hybrid-nanobiocomposite was optimized by RSM based on four responses of easy magnetic separation, biofilm formation along with protein, and carbohydrate contents in extracellular polymeric substances (EPS). The morphology and chemical composition of S-GrM hybrid-nanobiocomposite were investigated using various spectroscopic and microscopic analyses and subsequently explored for removal of Cr3+ ions. The hybrid-nanobiocomposite effectively removed 304.64 ± 14.02 mg/g of Cr3+ at pH 7.0 and 30 °C, which is found to be very high compared to the previously reported values. The high surface area of graphene, biofilm biomass of S. oneidensis and plenty of functional groups provided a unique structure to the S-GrM hybrid-nanobiocomposite for efficient removal of Cr3+ through synergistic interaction. The FTIR and zeta potential studies confirmed that electrostatic and chelation/complexation reaction played key roles in the adsorption process. The fabrication of S-GrM nanobiocomposite thus creates a novel hybrid 'living functional nanomaterial' for low cost, recyclable, and sustainable removal of Cr3+ from wastewater.

Green Synthesis of Nanomaterials with Special Reference to Environmental and Biomedical Applications

Current Science, 2015

Environmental benign bioinspired and/or biomimetic synthetic process of metal nanoparticles have ... more Environmental benign bioinspired and/or biomimetic synthetic process of metal nanoparticles have been developed for water purification and biomedical applications. In the synthetic process, the biomolecules acted as shape directing agent determining the crystal structure of the nanoparticles and also control the surface properties of the nanomaterials.

Microcapsules from diverse polyfunctional materials: synergistic interactions for a sharp response to pH changes

New Journal of Chemistry, 2018

Responsive microcapsules with strong synergistic interactions were prepared using a copolymer, si... more

Biomaterial Functionalized Graphene-Magnetite Nanocomposite: A Novel Approach for Simultaneous Removal of Anionic Dyes and Heavy-Metal Ions

ACS Sustainable Chemistry & Engineering, 2018

Despite of immense application potential of graphene in wastewater treatment, the colloidal stabi... more Despite of immense application potential of graphene in wastewater treatment, the colloidal stability, aggregation and recyclability remains a major challenge. To address this issue, we report biomaterial functionalized graphene-magnetite (Bio-GM) nanocomposite as a novel recyclable material for treatment of wastewater containing dyes and heavy metal. The integration of biomaterial including living cells of Shewanella oneidensis with graphene-magnetite nanocomposite was characterized through UV-vis, FTIR, FESEM and fluorescent microscopic studies. The contact angle measurement depicted the hydrophilic property (water contact-angle 27.93), while VSM result demonstrated super paramagnetic behavior of the nanocomposite with saturation magnetization value of 30.2 emu/g. The Bio-GM nanocomposite exhibited excellent adsorption capacity towards dyes and Cr 6+ in both single and multicomponent system with removal capacity of 189.63 ± 7.11, and 222.2 ± 8.64 mg/g of dyes and Cr +6 , respectively, suggesting selective binding capacity and high adsorption efficiency of Bio-GM nanocomposite. In the adsorption coupled redox reaction, the Cr +6 was reduced to Cr +3 through biocatalytic activity of Bio-GM nanocomposite. The nanocomposite could be easily regenerated and reused for multiple cycles of adsorption-desorption studies without release of graphene and magnetite, and thus eliminating the potential hazardous risk of nanomaterial to the environment. The proposed biomaterial functionalized graphene-magnetite nanocomposite thus offers a novel way for sustainable, affordable and efficient removal of coexisting toxic pollutants of dyes and heavy metal.

Metal Nanoparticle Loaded Magnetic-Chitosan Microsphere: Water Dispersible and Easily Separable Hybrid Metal Nano-biomaterial for Catalytic Applications

ACS Sustainable Chemistry & Engineering, 2017

We report a green synthesis of magnetically separable hybrid metal nano-biomaterial as water disp... more We report a green synthesis of magnetically separable hybrid metal nano-biomaterial as water dispersible and recyclable catalysts. The hybrid nano-biomaterial was prepared in three step process. The magnetic nanoparticles were initially synthesized by biomineralization process and coated with chitosan followed by binding and reduction of metal ions, which led to the formation of magnetically separable hybrid nano-biomaterial (Fe 3 O 4 @Ch-MNPs, M=Au and Pd). The chemical composition, morphology, thermal stability and magnetic behaviour of the hybrid nano-biomaterial were characterized with Zeta potential, FTIR, XPS, XRD, VSM, FESEM, and TEM analysis. The FESEM measurement demonstrated formation of highly dispersed Au and PdNPs on the surface of nano-biomaterial, while TGA and VSM analyses indicated high thermal stability and superparamagnetic behaviour of the hybrid nano-biomaterial. The XPS studies revealed formation of pure metallic nanoparticles on the surface of the hybrid nano-biomaterial. The as-synthesised hybrid nano-biomaterial were tested for several model reactions such as photocatalytic reduction of dye, hydrogenation of p-nitrophenol and Suzuki coupling reaction at ambient temperature and in aqueous solution. The catalytic efficiencies varied with the type of MNPs and Fe 3 O 4 @Ch-PdNPs exhibited superior catalytic activities in all chemical reactions. In addition the hybrid nano-biomaterial demonstrated excellent recyclability and reusability without significant loss of catalytic activities. Furthermore, leaching of metal ions was not detected during catalytic reaction confirming high stability and low environmental impact of the as-synthesised hybrid nano-biomaterial. We believe that our result will help to synthesize easily separable hybrid nano-biomaterial as heterogeneous catalyst through cost effective and eco-benign synthetic route for development of environmental sustainable nanotechnology.

Cationic Surfactant (CTAC) Assisted Synthesis of Silver Nanoparticles with Controlled Size: Optical, Morphological and Bactericidal Studies

Journal of Nanoengineering and Nanomanufacturing, 2015

Total Elimination of Polluting Chrome Shavings, Chrome, and Dye Exhaust Liquors of Tannery by a Method Using Keratin Hydrolysate

ACS Sustainable Chemistry & Engineering, 2015

ABSTRACT The solid and liquid waste management of tanneries has become a serious problem in the l... more ABSTRACT The solid and liquid waste management of tanneries has become a serious problem in the leather industry. In this study we have attempted and succeeded in eliminating these pollutants by a novel method, which has not been done anywhere so far. Keratin hydrolysate (KH) from poultry feathers have been utilized along with chrome shavings (CS) for total elimination of the polluting solid and liquid wastes in a tannery. In this process 100% fixation of the Cr from the chrome exhaust liquor and the dye from the dye exhaust liquor is achieved by the reactions of CS with KH. The infrared spectra of the different stages of CS confirm the fixation of Cr in the chrome shavings-keratin hydrolysate (CSKH) complex. In this work, apart from elimination of tannery pollutants, a leather-like flexible sheet is obtained that can be used in the footwear and leather goods industry. In the SEM evaluation the surface morphology of the product exhibits smoothness because of the incorporation of polyvinyl alcohol and ethylene glycol. The above findings will open new avenues for further research in solid and liquid waste management of tannery effluents.

Antimicrobial behavior of biosynthesized silica-silver nanocomposite for water disinfection: A mechanistic perspective

Journal of hazardous materials, Jan 24, 2015

The biosynthesis of nano-silica silver nanocomposite (NSAgNC) and it is as antibacterial effect o... more The biosynthesis of nano-silica silver nanocomposite (NSAgNC) and it is as antibacterial effect on gram-negative bacteria viz.Escherichia coli and Pseudomonas aeruginosa has been investigated for disinfection of water. The as-synthesized NSAgNC exhibited antibacterial activity in a dose dependent manner and ∼99.9% of E. coli and P. aeruginosa were killed at a concentration of 1.5mg/mL of NSAgNC (5.1wt% Ag) within 5h. The NSAgNC showed similar antibacterial activities both in oxic and anoxic conditions. The results further demonstrated that NSAgNC exhibited reactive oxygen species (ROS) independent "particle specific" antibacterial activity through multiple steps in absence of leached out Ag(+) ions. The initial binding of NSAgNC on the cell wall caused loss of cell membrane integrity and leakage of cytoplasmic materials. Inhibition of respiratory chain dehydrogenase by NSAgNC caused metabolic inactivation of the cells and affecting the cell viability. Genomic and proteomic...

Fabrication of Non-toxic reduced Graphene Oxide Protein Nano-framework as Sustained Antimicrobial Coating for Biomedical Application

ACS applied materials & interfaces, Jan 20, 2017

Bacterial colonization on medical devices is a major concern in the healthcare industry. In the p... more Bacterial colonization on medical devices is a major concern in the healthcare industry. In the present study we report synthesis of environmental sustainable reduced graphene oxide (rGO) at large scale through biosynthetic route and its potential application for antibacterial coating on medical devices. HRTEM image depicts formation of graphene nanosheet, while DLS and ζ potential studies reveal that in aqueous medium the average hydrodynamic size and surface charge of rGO are 4410 ± 116 nm and -25.2 ± 3.2 mV, respectively. The Raman, FTIR and XPS data suggest in-situ conjugation of protein with rGO. The as-synthesized rGO protein nano-framework exhibits dose-dependent antibacterial activity and potential of killing of 94% of Escherichia coli when treated with 80 μg/mL of rGO for 4 h. The hemolytic and cytotoxicity studies demonstrate that rGO protein nano-framework is highly biocompatible at the same concentration showing significant antimicrobial properties. The rGO coated on gla...

“Click” polymerization on a self-assembled monolayer: a convenient approach to functionalize various surfaces with polytriazoles

Chemical Communications, 2012

Bioinspired Metal Nanoparticle: Synthesis, Properties and Application

Nanomaterials, 2011

A green chemical approach for the synthesis of gold nanoparticles: characterization and mechanistic aspect

Reviews in Environmental Science and Bio/Technology, 2010

This IRCSET-EMPOWER (Irish Research Council for Science, Engineering and Technology Postdoctoral ... more This IRCSET-EMPOWER (Irish Research Council for Science, Engineering and Technology Postdoctoral Research Grant) project aims to improve current methodology for the synthesis of metal nanoparticles (NPs). The development of efficient methodology for metal nanomaterials synthesis is an economical and environmental challenge. While the current methods for NPs synthesis are often energy-intensive and involve toxic chemicals, NPs biosynthesis can be carried on at circumneutral pH and mild temperature, resulting in low cost and environmental impact. Nanomaterial biosynthesis has been already observed in magnetotactic bacteria, diatoms, and S-layer bacteria, however, controlled NPs biosynthesis is a relatively new area of research with considerable potential for development. A thorough understanding of the biochemical mechanism involved in NPs biosynthesis is needed, before biosynthetic methods can be economically competitive. The analysis and identification of active species in the nucleation and growth of metal NPs is a daunting task, due to the complexity of the microbial system. This project work focuses on the controlled biosynthesis of gold NPs by fungal microorganisms and aims to determine the biochemical mechanism involved in nucleation and growth of the particles.

Adsorption Behavior of Rhodamine B on Rhizopus oryzae Biomass

Langmuir, 2006

The removal of a carcinogenic dye rhodamine B (C. I. 45170) from wastewater by biomass of differe... more The removal of a carcinogenic dye rhodamine B (C. I. 45170) from wastewater by biomass of different moulds and yeasts is described. Among all of the fungal species tested, the biomass of Rhizopus oryzae MTCC 262 is found to be the most effective. Dye adsorption reaches maximum with the biomass harvested from the early stationary phase of growth. The optimum temperature and pH for adsorption are observed to be 40°C and 7.0, respectively. The adsorption rate is very fast initially and attains equilibrium after 5 h. The adsorption isotherm follows the Langmuir isotherm model satisfactorily within the studied dye concentration range. Of the different metabolic inhibitors tested, 2,4-ditrophenol (DNP) and N,N′-dicyclohexylcarbodiimide (DCCD) decrease dye adsorption by ∼30% suggesting the role of energy metabolism in the process. Spectrophotometric study indicates that the removal of rhodamine B by R. oryzae biomass involves an adsorption process. Scanning (SEM) and transmission (TEM) electron microscopic investigations have been carried out to understand the probable mechanism of the dye-biomass interaction.

A study on lead adsorption by Mucor rouxii biomass

Desalination, 2010

Removal of lead from its aqueous solutions by adsorption on different biomasses was studied. Muco... more Removal of lead from its aqueous solutions by adsorption on different biomasses was studied. Mucor rouxii biomass (MRB) had been found to be the most efficient in this respect and removed more than 90% of lead from its aqueous solution. Adsorption of lead by the biomass was dependent on pH and temperature. Maximum sorption was noted at the pH range of 5.0–6.0 and an increase in temperature above 30° C resulted in the decrease in adsorption indicating the exothermic nature of the process. The adsorption process was ...

Adsorption of cadmium on husk of Lathyrus sativus: Physico-chemical study

Colloids and Surfaces B: Biointerfaces, 2006

Adsorption of cadmium (II) from aqueous solution by low-cost biosorbents was investigated. Husk o... more Adsorption of cadmium (II) from aqueous solution by low-cost biosorbents was investigated. Husk of Lathyrus sativus (HLS) was found to be the most efficient in this respect and removed ∼95% of the metal. The influence of pH, temperature, contact time and metal ion concentration on the adsorption process by HLS was studied. Hydrogen ion concentration of the solution greatly influenced the process with an optimum at pH 5.0-6.0, whereas temperature had no significant effect. The process was very fast and more than 90% of the total adsorption took place within the first 5 min and was found to follow pseudo-second order rate kinetics. The adsorption data can better be explained by Langmuir isotherm model and the calculated maximum adsorption capacity was 35 mg/g of HLS at pH 5.0 and 30 • C. Scanning electron micrographs showed that cadmium was present as micro precipitate on the surface of the adsorbent. Cadmium replaced calcium of the biomass as revealed from the EDX analysis indicating that the adsorption proceeds through ion exchange mechanism. Cadmium could be desorbed from the loaded biomass by lowering pH ∼ 1.0 with mineral acid.