Naheed Ahmad | Patna Science college (Patna University),Patna (original) (raw)

Papers by Naheed Ahmad

Pantnagar Journal of Research, 2010

International Journal of Green Nanotechnology, Apr 1, 2011

... [CrossRef], [Web of Science ®] View all references , 24 24. Mukherjee, P., Ahmad, A., Mandal,... more ... [CrossRef], [Web of Science ®] View all references , 24 24. Mukherjee, P., Ahmad, A., Mandal, D., Senapati, S., Sainkar, SR and Khan, MI 2001. ... [CrossRef], [PubMed], [Web of Science ®] View all references ] starch, [ 31 31. Abu-Bakar, NH, Ismail, J. and Abu Bakar, M. 2007. ...

Journal of bionanoscience, Dec 1, 2009

ABSTRACT Development of reliable and eco-friendly process for synthesis of metallic nanoparticles... more ABSTRACT Development of reliable and eco-friendly process for synthesis of metallic nanoparticles is an important step in the field of the application of nanotechnology. One of the options to achieve this objective is to use of biological systems. In this research we report extracellular biosynthesis of silver nanoparticles (AgNPs) exploiting the local biodiversity as an alternative to the chemical process. The plants of Desmodium species viz. Desmodium latifolium were selected. These plants occur as weeds in the gangetic river belt of Patna in Northern India. It was observed that the synthesis process was quite rapid and silver nanoparticles were formed within minutes of silver ion coming in contact with the plant filtrate. UV-visible spectrum of the aqueous medium containing silver ions demonstrated a peak at 425 nm corresponding to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy (TEM) showed the formation of well-dispersed silver nanoparticles in the range of 5-30 nm. X-ray diffraction (XRD)-spectrum of the AgNPs exhibited 2θ values corresponding to the silver nanocrystal. FTIR analysis of the nanoparticles indicated the presence of proteins, which may be acting as capping agents around the nanoparticles. The process of reduction is extracellular and fast which may lead to the development of easy bio synthesis of silver nanoparticles.

Green and Sustainable Chemistry, 2012

Journal of Bionanoscience, 2014

In this paper we communicate the green synthesis of silver nanoparticles (AgNPs) by reduction of ... more In this paper we communicate the green synthesis of silver nanoparticles (AgNPs) by reduction of silver nitrate by exploiting a weed plant called shalparni (botanically known as Desmodium gangeticum), one of the important plants often used in the indigenous medicine system in India. The plant extracts were tested for free radical scavenging activities including the 1,1-diphenyl picrylhydrazyl (DPPH) and their total antioxidant capacity. The process for the synthesis of AgNPs using the plant extract was simple and rapid. The morphology and crystalline phase of the NPs were determined from transmission electron microscopy (TEM), selected area electron diffraction (SAED) and X-ray diffraction (XRD) spectra. TEM studies showed that the silver nanoparticles obtained were of sizes 10 ± 2 nm. Various phytochemicals present within the plant synergistically result in effective reduction of silver salts to nanoparticles. It also seems probable that their chemical framework is also effective in wrapping around the nanoparticles to provide excellent robustness against agglomeration.

International Journal of Green Nanotechnology, 2011

... [CrossRef], [Web of Science ®] View all references , 24 24. Mukherjee, P., Ahmad, A., Mandal,... more ... [CrossRef], [Web of Science ®] View all references , 24 24. Mukherjee, P., Ahmad, A., Mandal, D., Senapati, S., Sainkar, SR and Khan, MI 2001. ... [CrossRef], [PubMed], [Web of Science ®] View all references ] starch, [ 31 31. Abu-Bakar, NH, Ismail, J. and Abu Bakar, M. 2007. ...

License, which permits unrestricted use, distribution, and reproduction in any medium, provided t... more License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A single-step environmental friendly approach is employed to synthesize silver nanoparticles. The biomolecules found in plants induce the reduction of Ag + ions from silver nitrate to silver nanoparticles (AgNPs). UV-visible spectrum of the aqueous medium containing silver ions demonstrated a peak at 425 nm corresponding to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy (TEM) showed the formation of well-dispersed silver nanoparticles in the range of 5–20 nm. X-ray diffraction (XRD) spectrum of the AgNPs exhibited 2θ values corresponding to the silver nanocrystal. The process of reduction is extracellular and fast which may lead to the development of easy biosynthesis of silver nanoparticles. Plants during glycolysis produce a large amount of H + ions along with NAD which acts as a strong redoxing agent; this seems to ...

The minority community in Patna (Bihar), India uses selected herbs traditionally during pregnancy... more The minority community in Patna (Bihar), India uses selected herbs traditionally during pregnancy and post-partum care. Current study was deisgned to investigate the antibacterial activity of methanolic extracts of some herbs against Escherichia coli, Salmonella typhimurium, Staphylococus aureus and Enterococcus sp. The methanolic extract of Butea monosperma presented the highest anti-bacterial activity against Staphyllococus aureus and was effective against all bacterial strains tested.

Nanotechnology is a highly energized discipline of science and technology. One of the major chall... more Nanotechnology is a highly energized discipline of science and technology. One of the major challenges of nanotechnology is the synthesis of nanomaterials with a wide range of chemical compositions and sizes. Nanobiotechnology is a promising novel field specially for biodiverse countries like India.whose diversity is an asset which can be harnessed .Recently material scientists have been viewing with interest this diversity , particularly microorganisms as possible ecofriendly nanofactories.. In this paper, biosynthesis of nanomaterials is carried out from the microbial diversity obtained from the state of India, Bihar .Bacillus species isolated locally from the region has been used to synthesize silver nanoparticles at room temperature.

Current Organic Synthesis, 2017

Engineering Materials, 2016

Nanoclay has a great potential in various fields. Small amount of nanoclay can change the whole p... more Nanoclay has a great potential in various fields. Small amount of nanoclay can change the whole physical and chemical properties of polymers, paints, inks and lubricants by dispersing nanoclay layers into the polymer matrices. The flexibility of interlayer gallery of nanoclay helps in the release of drugs to the targeted place. The controlled release of drugs takes place on account of the drug incorporated within the nanoclay galleries. This makes these nanomaterials as potential materials with its application in pharmaceutical field. Organoclays, a type of nanoclay are also being utilized for waste water treatment in junction with other sorbents viz. activated carbon and alum. Organoclays have been found to be the finest material for water treatment especially when the water contains enough amounts of oil and grease or humic acid. The use of nanoclays as reinforcing agent or additives in polymers for various properties is exploited for various applications. This chapter provides an overview of nanoclays or types of nanoclays with significance on the utilization of nanoclays as the filler in polymer matrices for the synthesis/fabrication of polymer nanocomposites, drug delivery agents, viscosity modifier for coatings, inks and lubricants and nanoclays for industrial effluent as well as potable water treatment.

2009 Fifth International Conference on MEMS NANO, and Smart Systems, 2009

Abstract: Currently the need for various developmental models in material sciences to develop gre... more Abstract: Currently the need for various developmental models in material sciences to develop green technologies has been reemphasized. For biodiversity rich countries like India, low investment and sustainability of biological synthesis adds to its attraction. Plants respond to heavy ...

Advanced Materials Letters, 2012

We present a simple and eco-friendly biosynthesis of silver nanoparticles using Pomegranate peel ... more We present a simple and eco-friendly biosynthesis of silver nanoparticles using Pomegranate peel extract as the reducing agent. Peel extract of Pomegranate was challenged with silver nitrate (AgNO 3) and chloroauric acid (HAuCl 4) solution for the production of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs), respectively. The reaction process was simple for the formation of highly stable silver and gold nanoparticles at room temperature by using the biowaste of the fruit. The morphology and crystalline phase of the NPs were determined from UV-Vis spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction (SAED) and X-ray diffraction (XRD) spectra. TEM studies showed that the average particle size of silver nanoparticles were 5 ±1.5 nm whereas the gold nanoparticles were found to be 10 ±1.5 nm. An effort has been also been made to understand the possible involved mechanism for the biosynthesis of the NPs. Presumably biosynthetic products or reduced cofactors play an important role in the reduction of respective salts to nanoparticles.

Materials Sciences and Applications, 2010

Biotechnology research international, 2011

A single-step environmental friendly approach is employed to synthesize silver nanoparticles. The... more A single-step environmental friendly approach is employed to synthesize silver nanoparticles. The biomolecules found in plants induce the reduction of Ag(+) ions from silver nitrate to silver nanoparticles (AgNPs). UV-visible spectrum of the aqueous medium containing silver ions demonstrated a peak at 425 nm corresponding to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy (TEM) showed the formation of well-dispersed silver nanoparticles in the range of 5-20 nm. X-ray diffraction (XRD) spectrum of the AgNPs exhibited 2θ values corresponding to the silver nanocrystal. The process of reduction is extracellular and fast which may lead to the development of easy biosynthesis of silver nanoparticles. Plants during glycolysis produce a large amount of H(+) ions along with NAD which acts as a strong redoxing agent; this seems to be responsible for the formation of AgNPs. Water-soluble antioxidative agents like ascorbic acids further seem to be responsible fo...

Drug and chemical toxicology, Jan 29, 2018

The current study highlights rapid, sustainable, and cost-effective biosynthesis of silver (Ag), ... more The current study highlights rapid, sustainable, and cost-effective biosynthesis of silver (Ag), gold (Au) nanoparticles (NPs), and bimetallic Au-AgNPs composites using bio-waste extract of Trapa natans. Growth of the NPs was monitored spectrophotometrically and peak was observed at ∼525 nm, ∼450 nm, and ∼495 nm corresponding to Plasmon absorbance of AuNPs, AgNPs, and Au-AgNPs, respectively. Transmission electron microscopy (TEM) revealed the size of AgNPs (∼15 nm), AuNPs (∼25 nm), and Au-AgNPs (∼26-90 nm). Synthesized NPs follow the Gaussian bell curve and its crystalline nature was identified by X-ray diffraction (XRD). Furthermore, Au-AgNPs induced cytotoxicity in various cancer cells (HCT116, MDA-MB-231, and HeLa) effectively at 200 μg/mL. Au-AgNPs-exposed cancer cells exhibited apoptotic features such as nuclear condensation, mitochondrial membrane potential loss, and cleavage of casp-3 and poly (ADP-ribose) polymerase-1 (PARP). Au-AgNPs exposure enhanced reactive oxygen specie...

International Journal of Nanoparticles, 2012

We present a simple and eco-friendly biosynthesis of silver nanoparticles using Pomegranate peel ... more We present a simple and eco-friendly biosynthesis of silver nanoparticles using Pomegranate peel extract as the reducing agent. The extract was challenged with AgNO 3 solution for the production of silver nanoparticles (AgNPs). The reaction process was simple for the formation of highly stable silver nanoparticles at room temperature by using the biowaste of the fruit. The morphology and crystalline phase of the NPs was determined from UV-Vis spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD) spectra and Fourier-Transform IR spectroscopy (FTIR). TEM studies showed that the silver nanoparticles obtained were of sizes 5 ± 1.5 nm. An effort has also been made to understand the possible involved mechanism for the biosynthesis of AgNPs. Presumably biosynthetic products or reduced cofactors play an important role in the reduction of respective salts to nanoparticles.

Green and Sustainable Chemistry, Nov 16, 2012

The biosynthesis of nanoparticles has been proposed as a cost effective and environmental friendl... more The biosynthesis of nanoparticles has been proposed as a cost effective and environmental friendly alternative to chemical and physical methods. Plant mediated synthesis of nanoparticles is a green chemistry approach that intercomnects nanotechnology and plant biotechnology. In the present study, synthesis of silver nanoparticles (AgNPs) or (Green-Silver) has been demonstrated using extracts of Ananas comosus reducing aqueous silver nitrate. The AgNPs were characterized by Ultraviolet-Visible (UV-vis) Spectrometer, Energy Dispersive X-ray Analysis (EDAX), Selected Area Diffraction Pattern (SAED) and High Resolution Transmission Electron Microscopy (HRTEM). TEM micrographs showed spherical particles with an average size of 12 nm. The XRD pattern showed the characteristic Bragg peaks of (111), (200), (220) and (311) facets of the face center cubic (fcc) silver nanoparticles and confirmed that these nanoparticles are crystalline in nature. The different types of antioxidants presented in the pineapple juice synergistically reduce the Ag metal ions, as each antioxidant is unique in terms of its structure and antioxidant function. The reaction process was simple for formation of silver nanoparticles and AgNPs presented in the aqueous medium were quite stable, even up to 4 months of incubation. This work proved the capability of using biomaterial towards the synthesis of silver nanoparticle, by adopting the principles of green chemistry.

Journal of Bionanoscience, 2009

ABSTRACT Development of reliable and eco-friendly process for synthesis of metallic nanoparticles... more ABSTRACT Development of reliable and eco-friendly process for synthesis of metallic nanoparticles is an important step in the field of the application of nanotechnology. One of the options to achieve this objective is to use of biological systems. In this research we report extracellular biosynthesis of silver nanoparticles (AgNPs) exploiting the local biodiversity as an alternative to the chemical process. The plants of Desmodium species viz. Desmodium latifolium were selected. These plants occur as weeds in the gangetic river belt of Patna in Northern India. It was observed that the synthesis process was quite rapid and silver nanoparticles were formed within minutes of silver ion coming in contact with the plant filtrate. UV-visible spectrum of the aqueous medium containing silver ions demonstrated a peak at 425 nm corresponding to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy (TEM) showed the formation of well-dispersed silver nanoparticles in the range of 5-30 nm. X-ray diffraction (XRD)-spectrum of the AgNPs exhibited 2θ values corresponding to the silver nanocrystal. FTIR analysis of the nanoparticles indicated the presence of proteins, which may be acting as capping agents around the nanoparticles. The process of reduction is extracellular and fast which may lead to the development of easy bio synthesis of silver nanoparticles.

Journal of Biomaterials and Nanobiotechnology, 2011

In the present work silver nanoparticles (AgNPs) were synthesized extracellularly by bacteria Bac... more In the present work silver nanoparticles (AgNPs) were synthesized extracellularly by bacteria Bacillus cereus collected from the riverine belt of Gangetic Plain of India. The microbes were isolated, screened and characterized by morphological and biochemical analyses. The silver resistant strain was exposed to different concentrations of silver salt (Ag-NO 3). UV-visible spectrum of the supernatant of cell culture showed absorbance peak of AgNPs at ~ 435 nm.The shape and size of AgNPs were ascertained by High Resolution Transmission Electron Micrography (HRTEM), X-ray diffraction (XRD) and Energy Dispersive spectroscopy (EDS). Average size of the synthesized AgNPs was found to be in the range of 10-30 nm with spherical shape. AgNPs were tested against antibacterial potential of some common human pathogens.

Pantnagar Journal of Research, 2010

International Journal of Green Nanotechnology, Apr 1, 2011

... [CrossRef], [Web of Science ®] View all references , 24 24. Mukherjee, P., Ahmad, A., Mandal,... more ... [CrossRef], [Web of Science ®] View all references , 24 24. Mukherjee, P., Ahmad, A., Mandal, D., Senapati, S., Sainkar, SR and Khan, MI 2001. ... [CrossRef], [PubMed], [Web of Science ®] View all references ] starch, [ 31 31. Abu-Bakar, NH, Ismail, J. and Abu Bakar, M. 2007. ...

Journal of bionanoscience, Dec 1, 2009

ABSTRACT Development of reliable and eco-friendly process for synthesis of metallic nanoparticles... more ABSTRACT Development of reliable and eco-friendly process for synthesis of metallic nanoparticles is an important step in the field of the application of nanotechnology. One of the options to achieve this objective is to use of biological systems. In this research we report extracellular biosynthesis of silver nanoparticles (AgNPs) exploiting the local biodiversity as an alternative to the chemical process. The plants of Desmodium species viz. Desmodium latifolium were selected. These plants occur as weeds in the gangetic river belt of Patna in Northern India. It was observed that the synthesis process was quite rapid and silver nanoparticles were formed within minutes of silver ion coming in contact with the plant filtrate. UV-visible spectrum of the aqueous medium containing silver ions demonstrated a peak at 425 nm corresponding to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy (TEM) showed the formation of well-dispersed silver nanoparticles in the range of 5-30 nm. X-ray diffraction (XRD)-spectrum of the AgNPs exhibited 2θ values corresponding to the silver nanocrystal. FTIR analysis of the nanoparticles indicated the presence of proteins, which may be acting as capping agents around the nanoparticles. The process of reduction is extracellular and fast which may lead to the development of easy bio synthesis of silver nanoparticles.

Green and Sustainable Chemistry, 2012

Journal of Bionanoscience, 2014

In this paper we communicate the green synthesis of silver nanoparticles (AgNPs) by reduction of ... more In this paper we communicate the green synthesis of silver nanoparticles (AgNPs) by reduction of silver nitrate by exploiting a weed plant called shalparni (botanically known as Desmodium gangeticum), one of the important plants often used in the indigenous medicine system in India. The plant extracts were tested for free radical scavenging activities including the 1,1-diphenyl picrylhydrazyl (DPPH) and their total antioxidant capacity. The process for the synthesis of AgNPs using the plant extract was simple and rapid. The morphology and crystalline phase of the NPs were determined from transmission electron microscopy (TEM), selected area electron diffraction (SAED) and X-ray diffraction (XRD) spectra. TEM studies showed that the silver nanoparticles obtained were of sizes 10 ± 2 nm. Various phytochemicals present within the plant synergistically result in effective reduction of silver salts to nanoparticles. It also seems probable that their chemical framework is also effective in wrapping around the nanoparticles to provide excellent robustness against agglomeration.

International Journal of Green Nanotechnology, 2011

... [CrossRef], [Web of Science ®] View all references , 24 24. Mukherjee, P., Ahmad, A., Mandal,... more ... [CrossRef], [Web of Science ®] View all references , 24 24. Mukherjee, P., Ahmad, A., Mandal, D., Senapati, S., Sainkar, SR and Khan, MI 2001. ... [CrossRef], [PubMed], [Web of Science ®] View all references ] starch, [ 31 31. Abu-Bakar, NH, Ismail, J. and Abu Bakar, M. 2007. ...

License, which permits unrestricted use, distribution, and reproduction in any medium, provided t... more License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A single-step environmental friendly approach is employed to synthesize silver nanoparticles. The biomolecules found in plants induce the reduction of Ag + ions from silver nitrate to silver nanoparticles (AgNPs). UV-visible spectrum of the aqueous medium containing silver ions demonstrated a peak at 425 nm corresponding to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy (TEM) showed the formation of well-dispersed silver nanoparticles in the range of 5–20 nm. X-ray diffraction (XRD) spectrum of the AgNPs exhibited 2θ values corresponding to the silver nanocrystal. The process of reduction is extracellular and fast which may lead to the development of easy biosynthesis of silver nanoparticles. Plants during glycolysis produce a large amount of H + ions along with NAD which acts as a strong redoxing agent; this seems to ...

The minority community in Patna (Bihar), India uses selected herbs traditionally during pregnancy... more The minority community in Patna (Bihar), India uses selected herbs traditionally during pregnancy and post-partum care. Current study was deisgned to investigate the antibacterial activity of methanolic extracts of some herbs against Escherichia coli, Salmonella typhimurium, Staphylococus aureus and Enterococcus sp. The methanolic extract of Butea monosperma presented the highest anti-bacterial activity against Staphyllococus aureus and was effective against all bacterial strains tested.

Nanotechnology is a highly energized discipline of science and technology. One of the major chall... more Nanotechnology is a highly energized discipline of science and technology. One of the major challenges of nanotechnology is the synthesis of nanomaterials with a wide range of chemical compositions and sizes. Nanobiotechnology is a promising novel field specially for biodiverse countries like India.whose diversity is an asset which can be harnessed .Recently material scientists have been viewing with interest this diversity , particularly microorganisms as possible ecofriendly nanofactories.. In this paper, biosynthesis of nanomaterials is carried out from the microbial diversity obtained from the state of India, Bihar .Bacillus species isolated locally from the region has been used to synthesize silver nanoparticles at room temperature.

Current Organic Synthesis, 2017

Engineering Materials, 2016

Nanoclay has a great potential in various fields. Small amount of nanoclay can change the whole p... more Nanoclay has a great potential in various fields. Small amount of nanoclay can change the whole physical and chemical properties of polymers, paints, inks and lubricants by dispersing nanoclay layers into the polymer matrices. The flexibility of interlayer gallery of nanoclay helps in the release of drugs to the targeted place. The controlled release of drugs takes place on account of the drug incorporated within the nanoclay galleries. This makes these nanomaterials as potential materials with its application in pharmaceutical field. Organoclays, a type of nanoclay are also being utilized for waste water treatment in junction with other sorbents viz. activated carbon and alum. Organoclays have been found to be the finest material for water treatment especially when the water contains enough amounts of oil and grease or humic acid. The use of nanoclays as reinforcing agent or additives in polymers for various properties is exploited for various applications. This chapter provides an overview of nanoclays or types of nanoclays with significance on the utilization of nanoclays as the filler in polymer matrices for the synthesis/fabrication of polymer nanocomposites, drug delivery agents, viscosity modifier for coatings, inks and lubricants and nanoclays for industrial effluent as well as potable water treatment.

2009 Fifth International Conference on MEMS NANO, and Smart Systems, 2009

Abstract: Currently the need for various developmental models in material sciences to develop gre... more Abstract: Currently the need for various developmental models in material sciences to develop green technologies has been reemphasized. For biodiversity rich countries like India, low investment and sustainability of biological synthesis adds to its attraction. Plants respond to heavy ...

Advanced Materials Letters, 2012

We present a simple and eco-friendly biosynthesis of silver nanoparticles using Pomegranate peel ... more We present a simple and eco-friendly biosynthesis of silver nanoparticles using Pomegranate peel extract as the reducing agent. Peel extract of Pomegranate was challenged with silver nitrate (AgNO 3) and chloroauric acid (HAuCl 4) solution for the production of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs), respectively. The reaction process was simple for the formation of highly stable silver and gold nanoparticles at room temperature by using the biowaste of the fruit. The morphology and crystalline phase of the NPs were determined from UV-Vis spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction (SAED) and X-ray diffraction (XRD) spectra. TEM studies showed that the average particle size of silver nanoparticles were 5 ±1.5 nm whereas the gold nanoparticles were found to be 10 ±1.5 nm. An effort has been also been made to understand the possible involved mechanism for the biosynthesis of the NPs. Presumably biosynthetic products or reduced cofactors play an important role in the reduction of respective salts to nanoparticles.

Materials Sciences and Applications, 2010

Biotechnology research international, 2011

A single-step environmental friendly approach is employed to synthesize silver nanoparticles. The... more A single-step environmental friendly approach is employed to synthesize silver nanoparticles. The biomolecules found in plants induce the reduction of Ag(+) ions from silver nitrate to silver nanoparticles (AgNPs). UV-visible spectrum of the aqueous medium containing silver ions demonstrated a peak at 425 nm corresponding to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy (TEM) showed the formation of well-dispersed silver nanoparticles in the range of 5-20 nm. X-ray diffraction (XRD) spectrum of the AgNPs exhibited 2θ values corresponding to the silver nanocrystal. The process of reduction is extracellular and fast which may lead to the development of easy biosynthesis of silver nanoparticles. Plants during glycolysis produce a large amount of H(+) ions along with NAD which acts as a strong redoxing agent; this seems to be responsible for the formation of AgNPs. Water-soluble antioxidative agents like ascorbic acids further seem to be responsible fo...

Drug and chemical toxicology, Jan 29, 2018

The current study highlights rapid, sustainable, and cost-effective biosynthesis of silver (Ag), ... more The current study highlights rapid, sustainable, and cost-effective biosynthesis of silver (Ag), gold (Au) nanoparticles (NPs), and bimetallic Au-AgNPs composites using bio-waste extract of Trapa natans. Growth of the NPs was monitored spectrophotometrically and peak was observed at ∼525 nm, ∼450 nm, and ∼495 nm corresponding to Plasmon absorbance of AuNPs, AgNPs, and Au-AgNPs, respectively. Transmission electron microscopy (TEM) revealed the size of AgNPs (∼15 nm), AuNPs (∼25 nm), and Au-AgNPs (∼26-90 nm). Synthesized NPs follow the Gaussian bell curve and its crystalline nature was identified by X-ray diffraction (XRD). Furthermore, Au-AgNPs induced cytotoxicity in various cancer cells (HCT116, MDA-MB-231, and HeLa) effectively at 200 μg/mL. Au-AgNPs-exposed cancer cells exhibited apoptotic features such as nuclear condensation, mitochondrial membrane potential loss, and cleavage of casp-3 and poly (ADP-ribose) polymerase-1 (PARP). Au-AgNPs exposure enhanced reactive oxygen specie...

International Journal of Nanoparticles, 2012

We present a simple and eco-friendly biosynthesis of silver nanoparticles using Pomegranate peel ... more We present a simple and eco-friendly biosynthesis of silver nanoparticles using Pomegranate peel extract as the reducing agent. The extract was challenged with AgNO 3 solution for the production of silver nanoparticles (AgNPs). The reaction process was simple for the formation of highly stable silver nanoparticles at room temperature by using the biowaste of the fruit. The morphology and crystalline phase of the NPs was determined from UV-Vis spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD) spectra and Fourier-Transform IR spectroscopy (FTIR). TEM studies showed that the silver nanoparticles obtained were of sizes 5 ± 1.5 nm. An effort has also been made to understand the possible involved mechanism for the biosynthesis of AgNPs. Presumably biosynthetic products or reduced cofactors play an important role in the reduction of respective salts to nanoparticles.

Green and Sustainable Chemistry, Nov 16, 2012

The biosynthesis of nanoparticles has been proposed as a cost effective and environmental friendl... more The biosynthesis of nanoparticles has been proposed as a cost effective and environmental friendly alternative to chemical and physical methods. Plant mediated synthesis of nanoparticles is a green chemistry approach that intercomnects nanotechnology and plant biotechnology. In the present study, synthesis of silver nanoparticles (AgNPs) or (Green-Silver) has been demonstrated using extracts of Ananas comosus reducing aqueous silver nitrate. The AgNPs were characterized by Ultraviolet-Visible (UV-vis) Spectrometer, Energy Dispersive X-ray Analysis (EDAX), Selected Area Diffraction Pattern (SAED) and High Resolution Transmission Electron Microscopy (HRTEM). TEM micrographs showed spherical particles with an average size of 12 nm. The XRD pattern showed the characteristic Bragg peaks of (111), (200), (220) and (311) facets of the face center cubic (fcc) silver nanoparticles and confirmed that these nanoparticles are crystalline in nature. The different types of antioxidants presented in the pineapple juice synergistically reduce the Ag metal ions, as each antioxidant is unique in terms of its structure and antioxidant function. The reaction process was simple for formation of silver nanoparticles and AgNPs presented in the aqueous medium were quite stable, even up to 4 months of incubation. This work proved the capability of using biomaterial towards the synthesis of silver nanoparticle, by adopting the principles of green chemistry.

Journal of Bionanoscience, 2009

ABSTRACT Development of reliable and eco-friendly process for synthesis of metallic nanoparticles... more ABSTRACT Development of reliable and eco-friendly process for synthesis of metallic nanoparticles is an important step in the field of the application of nanotechnology. One of the options to achieve this objective is to use of biological systems. In this research we report extracellular biosynthesis of silver nanoparticles (AgNPs) exploiting the local biodiversity as an alternative to the chemical process. The plants of Desmodium species viz. Desmodium latifolium were selected. These plants occur as weeds in the gangetic river belt of Patna in Northern India. It was observed that the synthesis process was quite rapid and silver nanoparticles were formed within minutes of silver ion coming in contact with the plant filtrate. UV-visible spectrum of the aqueous medium containing silver ions demonstrated a peak at 425 nm corresponding to the plasmon absorbance of silver nanoparticles. Transmission electron microscopy (TEM) showed the formation of well-dispersed silver nanoparticles in the range of 5-30 nm. X-ray diffraction (XRD)-spectrum of the AgNPs exhibited 2θ values corresponding to the silver nanocrystal. FTIR analysis of the nanoparticles indicated the presence of proteins, which may be acting as capping agents around the nanoparticles. The process of reduction is extracellular and fast which may lead to the development of easy bio synthesis of silver nanoparticles.

Journal of Biomaterials and Nanobiotechnology, 2011

In the present work silver nanoparticles (AgNPs) were synthesized extracellularly by bacteria Bac... more In the present work silver nanoparticles (AgNPs) were synthesized extracellularly by bacteria Bacillus cereus collected from the riverine belt of Gangetic Plain of India. The microbes were isolated, screened and characterized by morphological and biochemical analyses. The silver resistant strain was exposed to different concentrations of silver salt (Ag-NO 3). UV-visible spectrum of the supernatant of cell culture showed absorbance peak of AgNPs at ~ 435 nm.The shape and size of AgNPs were ascertained by High Resolution Transmission Electron Micrography (HRTEM), X-ray diffraction (XRD) and Energy Dispersive spectroscopy (EDS). Average size of the synthesized AgNPs was found to be in the range of 10-30 nm with spherical shape. AgNPs were tested against antibacterial potential of some common human pathogens.