Sensor technology for the rapid detection of the analytes with high sensitivity and selectivity h... more Sensor technology for the rapid detection of the analytes with high sensitivity and selectivity has several challenges. Despite the challenges, colorimetric sensors have been widely accepted for its high sensitive and selective response towards various analytes. In this review, colorimetric sensors for the detection of biomolecules like protein , DNA, pathogen and chemical compounds like heavy metal ions, toxic gases and organic compounds have been elaborately discussed. The visible sensing mechanism based on Surface Plasmon Resonance (SPR) using metal nanoparticles like Au, Ag, thin film interference using SiO 2 and colorimetric array-based technique have been highlighted. The optical property of metal nanoparticles enables a visual color change during its interaction with the analytes owing to the dispersion and aggregation of nanoparticles. Recently, colorimetric changes using silica substrate for detection of protein and small molecules by thin film interference as a visible sensing mechanism has been developed without the usage of fluorescent or radioisotopes labels. Multilayer of biomaterials were used as a platform where reflection and interference of scattering light occur due to which color change happens leading to rapid sensing. Colorimetric array-based technique for the detection of organic compounds using chemoresponsive dyes has also been focused wherein the interaction of the analytes with the substrate coated with chemoresponsive dyes gives colorimetric change.
Silver nanoparticles are being explored for their attractive properties which enable them to be u... more Silver nanoparticles are being explored for their attractive properties which enable them to be used for the development of different hybrid products. Metal nanoparticles are being synthesized through biogenic routes to synthesize nanoparticles which can be more biocompatible and synthesis process is ecofriendly. In previous studies, we have synthesized silver nanoparticles using plant based extract as reducing agent and have developed a number of products utilizing such biosynthesized nanoparticles. Leaf extracts were extracted from weed plants instead of cash crops or beneficial plants. Some of the prominent products which are going to be discussed in this review are antimicrobial membranes (Cellulose acetate and Poly Vinyl Alcohol), hybrid tissue paper , antimicrobial ice, Photo – Enhanced Dye Sensitized Solar Cell (PE-DSSC), bactericidal cold cream.
This work demonstrates the effective surface functionalization of Ag, Au and bimetallic Ag-Au nan... more This work demonstrates the effective surface functionalization of Ag, Au and bimetallic Ag-Au nanoparticles using L-Histidine for colorimetric detection of dopamine(DA) which plays majorly in recognizing the neurological disorder. L-Histidine (L-His) capped Ag, Au, and bimetallic Ag-Au nanoparticles T are characterized using physico-chemical techniques. The optical behaviour of nanoparticles has been analysed at various time intervals using UV-Vis absorption spectroscopy. FT-IR results provide the evidence of chemical bonding between L-Histidine and metal nanoparticles. Its structure with the capping of L-His was clearly shown in HR-TEM images. The average size of nanoparticles has calculated from TEM image fringes are 11 nm, 5 nm and 6.5 nm respectively, matches with crystals size calculated from X-Ray diffraction pattern. Enhanced optical nature of nanoparticles provides the best platform to develop a colorimetric-based biosensor for DA detection. After addition of DA, a rapid colour change has been noted in colloids of nanoparticles. The substantial changes in absorbance and λmax in metal nanoparticles respect to DA concentration have been observed and formulated. This is one of the successive methods for trace level determination of DA and will be going to a significant material for designing biosensor to determine DA in real extracellular body fluids.
A highly sensitive, selective, and rapid interference green synthesis based determination of pote... more A highly sensitive, selective, and rapid interference green synthesis based determination of potential milk adulterant melamine has been reported here. Melamine is a nitrogenous compound added to milk for mimicking proteins, consumption of which leads to kidney stones and renal failures. Melamine interacts with ascorbic acid (AA) through strong hydrogen-bonding interactions, thus resulting in an interference/interruption in the formation of silver (Ag) nanoparti-cles which was confirmed by UV–Vis spectroscopy and Transmission Electron Microscopy (TEM). The corresponding benchmark validations for melamine spiked milk samples were performed using High Performance Liquid Chromatography (HPLC). This interference in the formation of Ag nanoparticles resulted in color change that varies with concentration of melamine, thereby enabling in-situ rapid sensing of melamine from milk to a lower limit of 0.1 ppm with a linear correlation coefficient of 0.9908.
Current study relates to the development of an electrical power-free, handheld microfluidic nanop... more Current study relates to the development of an electrical power-free, handheld microfluidic nanoparticle synthesizer for synthesis of uniform sized silver nanoparticles at room temperature. The synthesizer module consists of a custom designed microreactor and employs negative pressure based pumping mechanism for the electrical power free synthesis of metal nanoparticles. In order to realize a microreactor capable of on-site synthesis of monodisperse nanoparticles, optimization studies by bulk biosynthesis at varying ratios of the precursor and the reducing agent followed by UV–VIS absorption studies were performed to determine the appropriate mixing ratio. Later, a custom designed microfluidic micro-mixer was used to perform volumetric flow rate optimizations at the desired ratio using syringe pumps. From the knowledge of the precursor and reducing agent ratio and the flow rates, we modified the hydraulic resistance of micro-mixer inlets by varying the channel geometry to meet the optimized specifications leading to effective synthesis. The synthesized nanoparticles were characterized by UV–VIS spectroscopy, XPS, FTIR, EDS, HRTEM and SAED. The crystal lattice planes of [111] and [220] from the SAED pattern confirms the presence of silver nanoparticles. HRTEM study elucidates that the size of the synthesized nanoparticles is between 2 and 10 nm.
Current work deals with novel application of biosynthesized silver nanoparticles to make antimicr... more Current work deals with novel application of biosynthesized silver nanoparticles to make antimicrobial nano ice for preservation of fish. World fish production has increased by leaps and bounds. Fish products are distributed with minimal treatment before sale to the customer. In retail establishments, the fishes are regularly stored in ice to prevent their spoilage and growth of pathogens. Silver nano products are extensively used for various antimicrobial applications. Though silver based compounds are being used extensively in food storage application, there are no previous studies reporting the incorporation of metal nanoparticles in ice for enhanced storage of any food item. Silver nanoparticles biosynthesized using banana midrib extract having a size range of 20-40 nm has been utilized for the preparation of antimicrobial nano ice. Silver nanoparticle based ice has been found to decrease the amount of pathogens present on the surface of stored fish.
Instantaneous detection of melamine, a potential milk adulterant has been demonstrated at room te... more Instantaneous detection of melamine, a potential milk adulterant has been demonstrated at room temperature by means of interference biosynthesis of silver nanoparticles. The sensing mechanism is based on the colorimetric change observed during the synthesis of silver nanoparticles due to the presence of melamine added during the biosynthesis. Presence and absence of melamine led to either inhibition of nanoparticle formation or enable partial synthesis of nanoparticles which is detected spectrally. A limit of detection (LOD) of 0.1 ppm in water and 0.5 ppm in raw milk was detected by the proposed technique at room temperature. UV–vis spectroscopy and High Resolution Transmission Electron Microscopy (HR-TEM) have been used to detect the spectral Surface Plasmon Resonance (SPR) and morphological changes of synthesized silver nanoparticle with and without the presence of the analyte melamine. Further , interference synthesis based sensing of melamine was done with caffeic acid as a reducing agent which confirms the role of caffeic acid a major constituent of Parthenium leaf extract for interference biosynthesis based sensing. Melamine is detected from raw milk by interference biosynthesis based sensing after a facile milk pre-processing step. Thus the method can be converted into a workable handheld prototype for detection of melamine for in-situ field applications.
In the present study prevention and treatment of ornamental gold fishes against red spot and whit... more In the present study prevention and treatment of ornamental gold fishes against red spot and white spot diseases was attempted using silver nanoparticles. The uptake of silver nanoparticles and the biochemical changes were studied and their resultant toxicity was also studied. The starch stabilized silver nanoparticles could penetrate all tissues including the brain through Blood Brain Barrier. The results also demonstrated a cure from red spot and white spot diseases within 3days without showing any toxicity. The fishes showed immediate cure from infection and the infection was not observedfor more than one year till the death of the fish and hence a one time dose may give life long protection at very low concentration (10ng/g body weight) by simple bathing method. This is the first report on silver nanoparticle treatment for protozoan and fungal infection in fishes (Patent application 2267/CHE/2012).
ABSTRACT New functional nanocomposite materials with impregnated nanoparticles are in the fore fr... more ABSTRACT New functional nanocomposite materials with impregnated nanoparticles are in the fore front of nano based water treatment methods. In this chapter the recent developments on chitosan based nanocomposites having nanoparticles as impregnated materials and their applications in heavy metal removal will be discussed. More insight can be derived from our work on chitosan based nanocomposites, which are one of the less expensive nano products developed. The synergistic action of individual polymer (chitosan), which has inherent properties of heavy metal removal, with metal nanoparticles has been utilized. The hybrid composites exhibit better efficiency than those of conventional materials / products available in market for heavy metal removal.
Environmental pollution caused by heavy metals is a serious threat. In the present work, removal ... more Environmental pollution caused by heavy metals is a serious threat. In the present work, removal of chromium was carried out using chitosan–magnetite nanocomposite strip. Magnetite nanoparticles (Fe3O4) were synthesized using chemical co-precipitation method at 80 °C. The nanoparticles were characterized using UV–visible spectroscopy, fourier transform infrared spectroscopy, X-ray diffraction spectrometer, atomic force microscope, dynamic light scattering and vibrating sample magnetometer, which confirm the size, shape, crystalline nature and magnetic behaviour of nanoparticles. Atomic force microscope revealed that the particle size was 15–30 nm and spherical in shape. The magnetite nanoparticles were mixed with chitosan solution to form hybrid nanocomposite. Chitosan strip was casted with and without nanoparticle. The affinity of hybrid nanocomposite for chromium was studied using K2Cr2O7 (potassium dichromate) solution as the heavy metal solution containing Cr(VI) ions. Adsorption tests were carried out using chitosan strip and hybrid nanocomposite strip at different time intervals. Amount of chromium adsorbed by chitosan strip and chitosan–magnetite nanocomposite strip from aqueous solution was evaluated using UV–visible spectroscopy. The results confirm that the heavy metal removal efficiency of chitosan–magnetite nanocomposite strip is 92.33 %, which is higher when compared to chitosan strip, which is 29.39 %.
Microbicidal tissue paper is made by a simple method of impregnating biosynthesized silver nanopa... more Microbicidal tissue paper is made by a simple method of impregnating biosynthesized silver nanoparticles with the conventional tissue paper. A number of infections are being transmitted by conventional tissue paper especially through hospitals. Silver nanoparticles were synthesized by green synthetic route using the leaf extract of Eichornia crassipes, further characterized using UV vis spectroscopy exhibiting a SPR peak at 413nm and HRTEM having a size between 20 to 50 nm. We have developed a hybrid tissue paper for control of spreading of hospital infections. The hybrid tissue paper was characterized by X – Ray Diffraction and Field Emission Scanning Electron Microscopy in which the size of the nanoparticles present in the tissue paper were found to be ranging from 20 nm to 50 nm. Antimicrobial activity was evaluated against clinical pathogens - Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and release studies of nanoparticles from the hybrid tissue paper were carried out to ascertain the antimicrobial nature.
With the advent of diff erent nanomaterials, nanotechnology plays a key role in
water treatment. ... more With the advent of diff erent nanomaterials, nanotechnology plays a key role in water treatment. Metal nanoparticles, especially silver, copper and zero valent iron nanoparticles, have the properties of microbe inactivation and heavy metal removal. In this chapter we will be focusing on the role of hybrid metallic copper, silver and iron nanoparticles in wastewater treatment due to their ability for antimicrobial activities and removal of various pollutants. In our previous studies we have treated wastewater, textile and tannery effl uents using such multifunctional hybrid nanoparticles. We will also be discussing the existing multifunctional metal nanoparticle products available for wastewater treatment and new variations being made by researchers around the world.
A simple formulation of bactericidal cold cream using the biosynthesized silver nanoparticles (Ag... more A simple formulation of bactericidal cold cream using the biosynthesized silver nanoparticles (AgNPs) from
Cassia auriculata flower extract and their antibacterial activity was tested against various clinical pathogens such
as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus epidermidis. An ecofriendly
method was followed for the biosynthesis of AgNPs using C. auriculata flower extract as a reducing agent
15 at room temperature. The effect of different concentrations of flower extract and the various pH conditions of the
reaction medium toward the formation of NPs were studied. Surface plasmon resonance peaks were obtained from
403 nm to 428 nm. Further, the synthesized NPs were characterized by dynamic light scattering particle size
analysis, Zeta potential analysis, atomic force microscope, and high-resolution transmission electron microscopic
analysis.
Biosynthesis of copper, zero-valent iron
(ZVI), and silver nanoparticles using leaf extract of
... more Biosynthesis of copper, zero-valent iron
(ZVI), and silver nanoparticles using leaf extract of
Dodonaea viscosa has been investigated in this report.
There are no additional surfactants/polymers used as
capping or reducing agents for these syntheses. The
synthesized nanoparticles were characterized by UV–
Vis spectroscopy, X-ray diffraction, atomic force
microscopy, and high-resolution transmission electron
microscopy. The phase analysis was performed using
selected area electron diffraction. The pH dependence
of surface plasmon resonance and subsequent size
variation has been determined. The synthesized
nanoparticles showed spherical morphology and the
average size of 29, 27, and 16 nm for Cu, ZVI, and Ag
nanoparticles, respectively. Finally, biosynthesized
Cu, ZVI, and Ag nanoparticles were tested against
human pathogens viz. Gram-negative Escherichia
coli, Klebsiella pneumonia, Pseudomonas fluorescens
and Gram-positive Staphylococcus aureus and Bacillus
subtilis, and showed good antimicrobial activity.
Silver nanoparticles stabilized by soluble starch were synthesized and characterized. In vivo stu... more Silver nanoparticles stabilized by soluble starch were synthesized and characterized. In vivo studies in
rats showed no toxicity and revealed their distribution in various tissues and permeability across BBB. This
starch stabilized silver nanoparticles have good biological characteristics to act as a potential promising
vector for gene/drug delivery.
Sensor technology for the rapid detection of the analytes with high sensitivity and selectivity h... more Sensor technology for the rapid detection of the analytes with high sensitivity and selectivity has several challenges. Despite the challenges, colorimetric sensors have been widely accepted for its high sensitive and selective response towards various analytes. In this review, colorimetric sensors for the detection of biomolecules like protein , DNA, pathogen and chemical compounds like heavy metal ions, toxic gases and organic compounds have been elaborately discussed. The visible sensing mechanism based on Surface Plasmon Resonance (SPR) using metal nanoparticles like Au, Ag, thin film interference using SiO 2 and colorimetric array-based technique have been highlighted. The optical property of metal nanoparticles enables a visual color change during its interaction with the analytes owing to the dispersion and aggregation of nanoparticles. Recently, colorimetric changes using silica substrate for detection of protein and small molecules by thin film interference as a visible sensing mechanism has been developed without the usage of fluorescent or radioisotopes labels. Multilayer of biomaterials were used as a platform where reflection and interference of scattering light occur due to which color change happens leading to rapid sensing. Colorimetric array-based technique for the detection of organic compounds using chemoresponsive dyes has also been focused wherein the interaction of the analytes with the substrate coated with chemoresponsive dyes gives colorimetric change.
Silver nanoparticles are being explored for their attractive properties which enable them to be u... more Silver nanoparticles are being explored for their attractive properties which enable them to be used for the development of different hybrid products. Metal nanoparticles are being synthesized through biogenic routes to synthesize nanoparticles which can be more biocompatible and synthesis process is ecofriendly. In previous studies, we have synthesized silver nanoparticles using plant based extract as reducing agent and have developed a number of products utilizing such biosynthesized nanoparticles. Leaf extracts were extracted from weed plants instead of cash crops or beneficial plants. Some of the prominent products which are going to be discussed in this review are antimicrobial membranes (Cellulose acetate and Poly Vinyl Alcohol), hybrid tissue paper , antimicrobial ice, Photo – Enhanced Dye Sensitized Solar Cell (PE-DSSC), bactericidal cold cream.
This work demonstrates the effective surface functionalization of Ag, Au and bimetallic Ag-Au nan... more This work demonstrates the effective surface functionalization of Ag, Au and bimetallic Ag-Au nanoparticles using L-Histidine for colorimetric detection of dopamine(DA) which plays majorly in recognizing the neurological disorder. L-Histidine (L-His) capped Ag, Au, and bimetallic Ag-Au nanoparticles T are characterized using physico-chemical techniques. The optical behaviour of nanoparticles has been analysed at various time intervals using UV-Vis absorption spectroscopy. FT-IR results provide the evidence of chemical bonding between L-Histidine and metal nanoparticles. Its structure with the capping of L-His was clearly shown in HR-TEM images. The average size of nanoparticles has calculated from TEM image fringes are 11 nm, 5 nm and 6.5 nm respectively, matches with crystals size calculated from X-Ray diffraction pattern. Enhanced optical nature of nanoparticles provides the best platform to develop a colorimetric-based biosensor for DA detection. After addition of DA, a rapid colour change has been noted in colloids of nanoparticles. The substantial changes in absorbance and λmax in metal nanoparticles respect to DA concentration have been observed and formulated. This is one of the successive methods for trace level determination of DA and will be going to a significant material for designing biosensor to determine DA in real extracellular body fluids.
A highly sensitive, selective, and rapid interference green synthesis based determination of pote... more A highly sensitive, selective, and rapid interference green synthesis based determination of potential milk adulterant melamine has been reported here. Melamine is a nitrogenous compound added to milk for mimicking proteins, consumption of which leads to kidney stones and renal failures. Melamine interacts with ascorbic acid (AA) through strong hydrogen-bonding interactions, thus resulting in an interference/interruption in the formation of silver (Ag) nanoparti-cles which was confirmed by UV–Vis spectroscopy and Transmission Electron Microscopy (TEM). The corresponding benchmark validations for melamine spiked milk samples were performed using High Performance Liquid Chromatography (HPLC). This interference in the formation of Ag nanoparticles resulted in color change that varies with concentration of melamine, thereby enabling in-situ rapid sensing of melamine from milk to a lower limit of 0.1 ppm with a linear correlation coefficient of 0.9908.
Current study relates to the development of an electrical power-free, handheld microfluidic nanop... more Current study relates to the development of an electrical power-free, handheld microfluidic nanoparticle synthesizer for synthesis of uniform sized silver nanoparticles at room temperature. The synthesizer module consists of a custom designed microreactor and employs negative pressure based pumping mechanism for the electrical power free synthesis of metal nanoparticles. In order to realize a microreactor capable of on-site synthesis of monodisperse nanoparticles, optimization studies by bulk biosynthesis at varying ratios of the precursor and the reducing agent followed by UV–VIS absorption studies were performed to determine the appropriate mixing ratio. Later, a custom designed microfluidic micro-mixer was used to perform volumetric flow rate optimizations at the desired ratio using syringe pumps. From the knowledge of the precursor and reducing agent ratio and the flow rates, we modified the hydraulic resistance of micro-mixer inlets by varying the channel geometry to meet the optimized specifications leading to effective synthesis. The synthesized nanoparticles were characterized by UV–VIS spectroscopy, XPS, FTIR, EDS, HRTEM and SAED. The crystal lattice planes of [111] and [220] from the SAED pattern confirms the presence of silver nanoparticles. HRTEM study elucidates that the size of the synthesized nanoparticles is between 2 and 10 nm.
Current work deals with novel application of biosynthesized silver nanoparticles to make antimicr... more Current work deals with novel application of biosynthesized silver nanoparticles to make antimicrobial nano ice for preservation of fish. World fish production has increased by leaps and bounds. Fish products are distributed with minimal treatment before sale to the customer. In retail establishments, the fishes are regularly stored in ice to prevent their spoilage and growth of pathogens. Silver nano products are extensively used for various antimicrobial applications. Though silver based compounds are being used extensively in food storage application, there are no previous studies reporting the incorporation of metal nanoparticles in ice for enhanced storage of any food item. Silver nanoparticles biosynthesized using banana midrib extract having a size range of 20-40 nm has been utilized for the preparation of antimicrobial nano ice. Silver nanoparticle based ice has been found to decrease the amount of pathogens present on the surface of stored fish.
Instantaneous detection of melamine, a potential milk adulterant has been demonstrated at room te... more Instantaneous detection of melamine, a potential milk adulterant has been demonstrated at room temperature by means of interference biosynthesis of silver nanoparticles. The sensing mechanism is based on the colorimetric change observed during the synthesis of silver nanoparticles due to the presence of melamine added during the biosynthesis. Presence and absence of melamine led to either inhibition of nanoparticle formation or enable partial synthesis of nanoparticles which is detected spectrally. A limit of detection (LOD) of 0.1 ppm in water and 0.5 ppm in raw milk was detected by the proposed technique at room temperature. UV–vis spectroscopy and High Resolution Transmission Electron Microscopy (HR-TEM) have been used to detect the spectral Surface Plasmon Resonance (SPR) and morphological changes of synthesized silver nanoparticle with and without the presence of the analyte melamine. Further , interference synthesis based sensing of melamine was done with caffeic acid as a reducing agent which confirms the role of caffeic acid a major constituent of Parthenium leaf extract for interference biosynthesis based sensing. Melamine is detected from raw milk by interference biosynthesis based sensing after a facile milk pre-processing step. Thus the method can be converted into a workable handheld prototype for detection of melamine for in-situ field applications.
In the present study prevention and treatment of ornamental gold fishes against red spot and whit... more In the present study prevention and treatment of ornamental gold fishes against red spot and white spot diseases was attempted using silver nanoparticles. The uptake of silver nanoparticles and the biochemical changes were studied and their resultant toxicity was also studied. The starch stabilized silver nanoparticles could penetrate all tissues including the brain through Blood Brain Barrier. The results also demonstrated a cure from red spot and white spot diseases within 3days without showing any toxicity. The fishes showed immediate cure from infection and the infection was not observedfor more than one year till the death of the fish and hence a one time dose may give life long protection at very low concentration (10ng/g body weight) by simple bathing method. This is the first report on silver nanoparticle treatment for protozoan and fungal infection in fishes (Patent application 2267/CHE/2012).
ABSTRACT New functional nanocomposite materials with impregnated nanoparticles are in the fore fr... more ABSTRACT New functional nanocomposite materials with impregnated nanoparticles are in the fore front of nano based water treatment methods. In this chapter the recent developments on chitosan based nanocomposites having nanoparticles as impregnated materials and their applications in heavy metal removal will be discussed. More insight can be derived from our work on chitosan based nanocomposites, which are one of the less expensive nano products developed. The synergistic action of individual polymer (chitosan), which has inherent properties of heavy metal removal, with metal nanoparticles has been utilized. The hybrid composites exhibit better efficiency than those of conventional materials / products available in market for heavy metal removal.
Environmental pollution caused by heavy metals is a serious threat. In the present work, removal ... more Environmental pollution caused by heavy metals is a serious threat. In the present work, removal of chromium was carried out using chitosan–magnetite nanocomposite strip. Magnetite nanoparticles (Fe3O4) were synthesized using chemical co-precipitation method at 80 °C. The nanoparticles were characterized using UV–visible spectroscopy, fourier transform infrared spectroscopy, X-ray diffraction spectrometer, atomic force microscope, dynamic light scattering and vibrating sample magnetometer, which confirm the size, shape, crystalline nature and magnetic behaviour of nanoparticles. Atomic force microscope revealed that the particle size was 15–30 nm and spherical in shape. The magnetite nanoparticles were mixed with chitosan solution to form hybrid nanocomposite. Chitosan strip was casted with and without nanoparticle. The affinity of hybrid nanocomposite for chromium was studied using K2Cr2O7 (potassium dichromate) solution as the heavy metal solution containing Cr(VI) ions. Adsorption tests were carried out using chitosan strip and hybrid nanocomposite strip at different time intervals. Amount of chromium adsorbed by chitosan strip and chitosan–magnetite nanocomposite strip from aqueous solution was evaluated using UV–visible spectroscopy. The results confirm that the heavy metal removal efficiency of chitosan–magnetite nanocomposite strip is 92.33 %, which is higher when compared to chitosan strip, which is 29.39 %.
Microbicidal tissue paper is made by a simple method of impregnating biosynthesized silver nanopa... more Microbicidal tissue paper is made by a simple method of impregnating biosynthesized silver nanoparticles with the conventional tissue paper. A number of infections are being transmitted by conventional tissue paper especially through hospitals. Silver nanoparticles were synthesized by green synthetic route using the leaf extract of Eichornia crassipes, further characterized using UV vis spectroscopy exhibiting a SPR peak at 413nm and HRTEM having a size between 20 to 50 nm. We have developed a hybrid tissue paper for control of spreading of hospital infections. The hybrid tissue paper was characterized by X – Ray Diffraction and Field Emission Scanning Electron Microscopy in which the size of the nanoparticles present in the tissue paper were found to be ranging from 20 nm to 50 nm. Antimicrobial activity was evaluated against clinical pathogens - Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and release studies of nanoparticles from the hybrid tissue paper were carried out to ascertain the antimicrobial nature.
With the advent of diff erent nanomaterials, nanotechnology plays a key role in
water treatment. ... more With the advent of diff erent nanomaterials, nanotechnology plays a key role in water treatment. Metal nanoparticles, especially silver, copper and zero valent iron nanoparticles, have the properties of microbe inactivation and heavy metal removal. In this chapter we will be focusing on the role of hybrid metallic copper, silver and iron nanoparticles in wastewater treatment due to their ability for antimicrobial activities and removal of various pollutants. In our previous studies we have treated wastewater, textile and tannery effl uents using such multifunctional hybrid nanoparticles. We will also be discussing the existing multifunctional metal nanoparticle products available for wastewater treatment and new variations being made by researchers around the world.
A simple formulation of bactericidal cold cream using the biosynthesized silver nanoparticles (Ag... more A simple formulation of bactericidal cold cream using the biosynthesized silver nanoparticles (AgNPs) from
Cassia auriculata flower extract and their antibacterial activity was tested against various clinical pathogens such
as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus epidermidis. An ecofriendly
method was followed for the biosynthesis of AgNPs using C. auriculata flower extract as a reducing agent
15 at room temperature. The effect of different concentrations of flower extract and the various pH conditions of the
reaction medium toward the formation of NPs were studied. Surface plasmon resonance peaks were obtained from
403 nm to 428 nm. Further, the synthesized NPs were characterized by dynamic light scattering particle size
analysis, Zeta potential analysis, atomic force microscope, and high-resolution transmission electron microscopic
analysis.
Biosynthesis of copper, zero-valent iron
(ZVI), and silver nanoparticles using leaf extract of
... more Biosynthesis of copper, zero-valent iron
(ZVI), and silver nanoparticles using leaf extract of
Dodonaea viscosa has been investigated in this report.
There are no additional surfactants/polymers used as
capping or reducing agents for these syntheses. The
synthesized nanoparticles were characterized by UV–
Vis spectroscopy, X-ray diffraction, atomic force
microscopy, and high-resolution transmission electron
microscopy. The phase analysis was performed using
selected area electron diffraction. The pH dependence
of surface plasmon resonance and subsequent size
variation has been determined. The synthesized
nanoparticles showed spherical morphology and the
average size of 29, 27, and 16 nm for Cu, ZVI, and Ag
nanoparticles, respectively. Finally, biosynthesized
Cu, ZVI, and Ag nanoparticles were tested against
human pathogens viz. Gram-negative Escherichia
coli, Klebsiella pneumonia, Pseudomonas fluorescens
and Gram-positive Staphylococcus aureus and Bacillus
subtilis, and showed good antimicrobial activity.
Silver nanoparticles stabilized by soluble starch were synthesized and characterized. In vivo stu... more Silver nanoparticles stabilized by soluble starch were synthesized and characterized. In vivo studies in
rats showed no toxicity and revealed their distribution in various tissues and permeability across BBB. This
starch stabilized silver nanoparticles have good biological characteristics to act as a potential promising
vector for gene/drug delivery.
Th e greatest challenge in the 21st century is to provide new innovative water treatment methods.... more Th e greatest challenge in the 21st century is to provide new innovative water treatment methods. Th e conventional treatment processes are becoming incompetent by demands of space, energy, and economy and environment sustainability. Th e current, rapidly growing considerations have given room for sustainable alternative approaches of being greener, cheaper and energy effi cient. Amongst various biological methods to treat municipal wastewater like lagoons, aerobic oxidation ponds, anaerobic treatment chambers, dissolved air fl oatation and others, recently algal-based treatments are being most explored because of its viability for enhancement of treatment effi ciency and also advantage of added-value products. Th is chapter elaborates the sustainable algal-based approaches for energy-effi cient municipal wastewater treatment. Th e natural algal consortia dynamics gives a smart mode of enhancing the nutrient recovery and growth of algal biomass, hence a profi cient wastewater treatment. Th e chapter explores on the unknown potentials of the algae for energy-effi cient wastewater treatment. Th e algal consortia treating the wastewater have innate ability of biofl occulation, which exacerbates the
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and formulated. This is one of the successive methods for trace level determination of DA and will be going to a significant material for designing biosensor to determine DA in real extracellular body fluids.
diseases was attempted using silver nanoparticles. The uptake of silver nanoparticles and the biochemical
changes were studied and their resultant toxicity was also studied. The starch stabilized silver
nanoparticles could penetrate all tissues including the brain through Blood Brain Barrier. The results also
demonstrated a cure from red spot and white spot diseases within 3days without showing any toxicity.
The fishes showed immediate cure from infection and the infection was not observedfor more than one
year till the death of the fish and hence a one time dose may give life long protection at very low
concentration (10ng/g body weight) by simple bathing method. This is the first report on silver
nanoparticle treatment for protozoan and fungal infection in fishes (Patent application 2267/CHE/2012).
water treatment. Metal nanoparticles, especially silver, copper and zero valent
iron nanoparticles, have the properties of microbe inactivation and heavy metal
removal. In this chapter we will be focusing on the role of hybrid metallic copper, silver and iron nanoparticles in wastewater treatment due to their ability for antimicrobial
activities and removal of various pollutants. In our previous studies we have treated wastewater, textile and tannery effl uents using such multifunctional hybrid nanoparticles. We will also be discussing the existing multifunctional metal nanoparticle products available for wastewater treatment and new variations being made by researchers around the world.
Cassia auriculata flower extract and their antibacterial activity was tested against various clinical pathogens such
as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus epidermidis. An ecofriendly
method was followed for the biosynthesis of AgNPs using C. auriculata flower extract as a reducing agent
15 at room temperature. The effect of different concentrations of flower extract and the various pH conditions of the
reaction medium toward the formation of NPs were studied. Surface plasmon resonance peaks were obtained from
403 nm to 428 nm. Further, the synthesized NPs were characterized by dynamic light scattering particle size
analysis, Zeta potential analysis, atomic force microscope, and high-resolution transmission electron microscopic
analysis.
(ZVI), and silver nanoparticles using leaf extract of
Dodonaea viscosa has been investigated in this report.
There are no additional surfactants/polymers used as
capping or reducing agents for these syntheses. The
synthesized nanoparticles were characterized by UV–
Vis spectroscopy, X-ray diffraction, atomic force
microscopy, and high-resolution transmission electron
microscopy. The phase analysis was performed using
selected area electron diffraction. The pH dependence
of surface plasmon resonance and subsequent size
variation has been determined. The synthesized
nanoparticles showed spherical morphology and the
average size of 29, 27, and 16 nm for Cu, ZVI, and Ag
nanoparticles, respectively. Finally, biosynthesized
Cu, ZVI, and Ag nanoparticles were tested against
human pathogens viz. Gram-negative Escherichia
coli, Klebsiella pneumonia, Pseudomonas fluorescens
and Gram-positive Staphylococcus aureus and Bacillus
subtilis, and showed good antimicrobial activity.
rats showed no toxicity and revealed their distribution in various tissues and permeability across BBB. This
starch stabilized silver nanoparticles have good biological characteristics to act as a potential promising
vector for gene/drug delivery.
and formulated. This is one of the successive methods for trace level determination of DA and will be going to a significant material for designing biosensor to determine DA in real extracellular body fluids.
diseases was attempted using silver nanoparticles. The uptake of silver nanoparticles and the biochemical
changes were studied and their resultant toxicity was also studied. The starch stabilized silver
nanoparticles could penetrate all tissues including the brain through Blood Brain Barrier. The results also
demonstrated a cure from red spot and white spot diseases within 3days without showing any toxicity.
The fishes showed immediate cure from infection and the infection was not observedfor more than one
year till the death of the fish and hence a one time dose may give life long protection at very low
concentration (10ng/g body weight) by simple bathing method. This is the first report on silver
nanoparticle treatment for protozoan and fungal infection in fishes (Patent application 2267/CHE/2012).
water treatment. Metal nanoparticles, especially silver, copper and zero valent
iron nanoparticles, have the properties of microbe inactivation and heavy metal
removal. In this chapter we will be focusing on the role of hybrid metallic copper, silver and iron nanoparticles in wastewater treatment due to their ability for antimicrobial
activities and removal of various pollutants. In our previous studies we have treated wastewater, textile and tannery effl uents using such multifunctional hybrid nanoparticles. We will also be discussing the existing multifunctional metal nanoparticle products available for wastewater treatment and new variations being made by researchers around the world.
Cassia auriculata flower extract and their antibacterial activity was tested against various clinical pathogens such
as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus epidermidis. An ecofriendly
method was followed for the biosynthesis of AgNPs using C. auriculata flower extract as a reducing agent
15 at room temperature. The effect of different concentrations of flower extract and the various pH conditions of the
reaction medium toward the formation of NPs were studied. Surface plasmon resonance peaks were obtained from
403 nm to 428 nm. Further, the synthesized NPs were characterized by dynamic light scattering particle size
analysis, Zeta potential analysis, atomic force microscope, and high-resolution transmission electron microscopic
analysis.
(ZVI), and silver nanoparticles using leaf extract of
Dodonaea viscosa has been investigated in this report.
There are no additional surfactants/polymers used as
capping or reducing agents for these syntheses. The
synthesized nanoparticles were characterized by UV–
Vis spectroscopy, X-ray diffraction, atomic force
microscopy, and high-resolution transmission electron
microscopy. The phase analysis was performed using
selected area electron diffraction. The pH dependence
of surface plasmon resonance and subsequent size
variation has been determined. The synthesized
nanoparticles showed spherical morphology and the
average size of 29, 27, and 16 nm for Cu, ZVI, and Ag
nanoparticles, respectively. Finally, biosynthesized
Cu, ZVI, and Ag nanoparticles were tested against
human pathogens viz. Gram-negative Escherichia
coli, Klebsiella pneumonia, Pseudomonas fluorescens
and Gram-positive Staphylococcus aureus and Bacillus
subtilis, and showed good antimicrobial activity.
rats showed no toxicity and revealed their distribution in various tissues and permeability across BBB. This
starch stabilized silver nanoparticles have good biological characteristics to act as a potential promising
vector for gene/drug delivery.