biogenic synthesis and applications of metal nanoparticles
TRANSCRIPT
BIOGENIC SYNTHESIS AND BIOGENIC SYNTHESIS AND APPLICATIONS OF METAL APPLICATIONS OF METAL
NANOPARTICLESNANOPARTICLES
Why Nano Particles ?
Nanoparticles are of interest because of the new properties (such as chemical reactivity and optical behaviour) that they exhibit compared with larger particles of the same materials.
For example, titanium dioxide and zinc oxide become transparent at the nanoscale and have found application in sunscreens.
Nanoparticles have a range of potential applications: in cosmetics, textiles and paints. in drug delivery. as catalysts.
Nanoparticles and Nanoparticles and Bulk MaterialsBulk Materials
o Metallic nanoparticles have different physical and chemical properties from bulk metals
o Nanoparticles have unique optical, electronic and chemical properties.
o As the dimensions of the material is reduced the electronic properties change drastically.
o Magnetic properties are also different between bulk and nanomaterials
Nano-scale effects on properties
Synthesis- Bottom Up - Liquid Phase Methods
The chemical reduction (liquid/liquid) method carried out by the reduction of metal ions to their zero oxidation states (i.e., Mn+ → M0)
Principal advantage of this method is the facile fabrication of particles of various shapes viz., nanorods, nanowires, nanoprisms, nanoplates, and hollow nanoparticles
It is possible to fine-tune the shape and size of the nanoparticles by changing the reducing agent, dispersing agent, reaction time and the temperature
Plant Extracts as Reducing Plant Extracts as Reducing AgentsAgents
Plant sources containing the phyto constituents viz., Plant sources containing the phyto constituents viz., Tannins, Alkaloids, Polyphenols, Flavonoids, Citric acid Tannins, Alkaloids, Polyphenols, Flavonoids, Citric acid are are Good reducing agentsGood reducing agentsEasily availableEasily availableCost effectiveCost effectiveEco-friendlyEco-friendlyDifferent size and shapes of nanoparticles are also Different size and shapes of nanoparticles are also prepared using plant extractsprepared using plant extracts
Silver Silver NanoparticlesNanoparticles
Among various noble metal nanoparticles, silver Among various noble metal nanoparticles, silver
nanoparticles (AgNPs) are of great interest to the nanoparticles (AgNPs) are of great interest to the
researchers because of easy availability, very low researchers because of easy availability, very low
cost and emerging applications in the areas viz., cost and emerging applications in the areas viz.,
catalysis, medicine, energy, sensors and optics. catalysis, medicine, energy, sensors and optics.
Factors affecting the formation of Factors affecting the formation of AgNpsAgNps
Concentration of AgNOConcentration of AgNO33
pH of the reactionpH of the reaction Concentration of the ExtractConcentration of the Extract Temperature and EnvironmentTemperature and Environment Reaction time and LightReaction time and Light
Characterization of Characterization of NanoparticlesNanoparticles
Visual observation and UV-Vis spectroscopyVisual observation and UV-Vis spectroscopy FT-IR Spectroscopy (To analyze capping mechanism)FT-IR Spectroscopy (To analyze capping mechanism) X-Ray Diffraction (To analyze geometry)X-Ray Diffraction (To analyze geometry) DLS (To analyze size distribution)with Zeta potential DLS (To analyze size distribution)with Zeta potential
(To analyze the stability)(To analyze the stability) HR-TEM (To investigate the size and distribution)HR-TEM (To investigate the size and distribution) EDS (To analyze elements presents in colloidal nano)EDS (To analyze elements presents in colloidal nano)
Shape dependent SPR of AgNPsShape dependent SPR of AgNPs
Various colors of AgNPs with different shapes
Size dependent SPR of AgNPsSize dependent SPR of AgNPs
Blue Shift – Decrease in particle sizeBlue Shift – Decrease in particle sizeRed Shift – Increase in particle sizeRed Shift – Increase in particle size
High Resolution –High Resolution –Transmission Electron Transmission Electron
MicroscopyMicroscopy
TEM images of Different TEM images of Different size of AgNPssize of AgNPs
TEM images of silver nanoparticles with diameters of 20 nm, 60 nm and 100 nm.
Scale bars are 50 nm.
Triangular gold nanoparticles – using Triangular gold nanoparticles – using Lemongrass extractLemongrass extract
Dynamic Light ScatteringDynamic Light Scattering
Dynamic Light Scattering (DLS) is an important tool for characterizing the size of nanoparticles in solution.
DLS measures the light scattered from a laser that passes through a colloidal solution and by analyzing the modulation of the scattered light intensity as a function of time, the hydrodynamic size of particles and particle agglomerates can be determined.
Larger particles will diffuse slower than smaller particles.
Zeta Zeta potentialpotential• Zeta Potential analysis is a technique for determining
the surface charge of nanoparticles which attracts a thin layer of ions of opposite charge to the nanoparticle surface from solution (colloids).
• The magnitude of the zeta potential is predictive of the colloidal stability.
• Nanoparticles with Zeta Potential values greater than +25 mV or less than -25 mV typically have high
degrees of stability. Dispersions with a low zeta potential value will eventually aggregate due to van der Waal inter-particle attractions.
Works done in our Works done in our lab lab
Visual observation and UV-Vis spectrum of AgNPs synthesized using T. chebula
Effect of pH on formation of AgNPs synthesized using T. chebula
Blue shift was observed (acidic to basic pH)– Particle size decreases
Synthesis of AgNPs by T. chebula
Characterization of AgNPs synthesized Characterization of AgNPs synthesized using using T. chebulaT. chebula
FT-IR spectra of aq. Extract of T. chebula (A) and synthesized AgNPs (B) XRD pattern of synthesized AgNPs using T. chebula
HR-TEM and SAED images of AgNPs (25 nm)
DLS (30 nm) and Zetapotential (-30.2 mV)
Characterization of AgNPs synthesized Characterization of AgNPs synthesized using using T. chebulaT. chebula
UV–Vis spectra of methylene blue reduction by Terminalia chebula capped AgNPs
Reduction of methylene blue using Reduction of methylene blue using biogenic AgNPs synthesizedbiogenic AgNPs synthesized
Ag Ag + e
Ag + e Ag
Reduced
Methylene blue(Blue color)
Leucomethylene blue(Colorless)e
e
Terminalia chebula Fruit extract Oxidized product+e
e
Start Here
S
N
NNH3C
CH3
CH3
CH3Cl-S
HN
NNH3C
CH3
CH3
CH3
Catalytic action of AgNPs in the presence of Terminalia chebula on the degradation of methylene blue (electron relay effect)
Characterization of AgNPs synthesized using Characterization of AgNPs synthesized using P. P. granatumgranatum
UV-Vis spectra of Aq. Extract of P. granatum (A) UV-Vis spectra of Aq. Extract of P. granatum (A) synthesized AgNPs (initial) (B) After 10 min (C)synthesized AgNPs (initial) (B) After 10 min (C)
FT-IR spectra of Aq. Peel extract of P. granatum (A) FT-IR spectra of Aq. Peel extract of P. granatum (A) synthesized AgNPs (B)synthesized AgNPs (B)
A B
C
(111)
Characterization of AgNPs synthesized using Characterization of AgNPs synthesized using P. P. granatumgranatum
HR-TEM and DLS images of AgNPs synthesized using P. granatum (40 nm – distorted spherical)
Reduction of 4-NP by NaBHReduction of 4-NP by NaBH44 in the presence of in the presence of AgNPs synthesized using AgNPs synthesized using P. granatumP. granatum
Polyphenols
Extract BiogenicAgNPs
BH4
BiogenicAgNPs
HH H
BiogenicAgNPs
H HH Biogenic
AgNPs
H
4-AP
4-NP 4-NP
0.01 MAgNO3
Catalytic action of AgNPs on the reduction of 4-NP (Langmuir-Hinshelwood model)
UV-Vis spectra of 4-nitrophenol reduction by NaBH4
using AgNPs as catalyst
A- 4-nitrophenolB- 4-nitrophenolateC- 4-aminophenol
Capping Capping MechanismMechanism
OH
OH
HO
O-
O-
HO
+ 2 H+ + 2 e-2 Ag
O-Ag+
O-Ag+
HO
OO
HO
O
O
OH
O
O
OH
O O
OH
Ag
Capping of AgNPs
Phytoconstituent
Stabilized through electrostaticallyStabilized through electrostatically
Characterization of AgNPs synthesized using Characterization of AgNPs synthesized using A. A. niloticanilotica
Phytoconstituents of Acacia nilotica Effect of concentration of Acacia nilotica extract
Visual observation at various pH
Characterization of AgNPs synthesized using Characterization of AgNPs synthesized using A. A. niloticanilotica
FT-IR spectra of Acacia nilotica and synthesized AgNPs HR-TEM images of AgNPs synthesized using
A. nilotica
Ag+
H2O
GC/AgNPsCl
CH3
TolueneBenzyl chloride
Acacia nilotica pods
AgNPs
AgNPsAgNPs
AgNPs
AgNPs
Electrocatalytic activity of AgNPs
Role of AgNPs synthesized using Role of AgNPs synthesized using A. nilotica A. nilotica on reduction of on reduction of benzyl chloridebenzyl chloride
Electrode Potential (V) Current density × 10-
5 (A)GC -0.81 -6.14
Bulk silver -0.78 -7.19GC/AgNPs -0.74 -8.22
Negative shift of reduction potential of GC/AgNPs
Indicates the catalytic activity of biogenic AgNPs
HO
HO
H3C CH3
O
OHHO
H
HH3C CH3
Arjunic acid
HO
CH3 CH3 HHO
H H CH3
HO
CH3
H3C CH3
OH
O
CH3
CH3
Arjunolic acid
HO
OH
HO
CH3
CH3
CH3
CH3
H3C CH3
HO
O
OH
Arjungenin
Terminalia cuneata
Major Phytoconstituents -Terminalia cuneata
Synthesis of AgNPs using Synthesis of AgNPs using Terminalia cuneataTerminalia cuneata(Revision submitted to Colloids and Surfaces: B)
200 300 400 500 600 700 8000.00
0.05
0.10
0.15
0.20
Abs
orba
nce
Wavelength ( (nm))
0.50 ml (413 nm) 1.00 ml (415 nm) 1.75 ml (415 nm) 2.00 ml (415 nm) 2.50 ml (415 nm)
200 300 400 500 600 700 8000.0
0.5
Abs
orba
nce
Wavelength ( (nm))
0.50 ml (422 nm) 1.00 ml (422 nm) 1.75 ml (423 nm) 2.00 ml (424 nm) 2.50 ml (426 nm)
200 300 400 500 600 700 8000.0
0.5
pH - 9
pH - 8
pH - 7
pH - 5
Abs
orba
nce
Wavelength ( (nm))
417 nm 417 nm 416 nm 416 nm 413 nm
pH - 6
200 300 400 500 600 700 8000.0
0.5
1.0
Abs
orba
nce
Wavelength ( (nm))
420 nm 418 nm 417 nm 412 nm 399 & 545 nm
pH - 9
pH - 8
pH - 7
pH - 6
pH - 5
Synthesis of AgNPs at 10 min usingTerminalia cuneataSynthesis of AgNPs at 24 h usingTerminalia cuneata
Efeect of pH on AgNPs synthesis – at 10 min Efeect of pH on AgNPs synthesis – at 24 h
Absorbance increasesRed shift – Size increases
Λmax- 413 – Mostly spherical
Red shift – Size increases
Blue shift – Size decreases Blue shift – Size decreases & anisotropic
Characterization of AgNPs synthesized using Characterization of AgNPs synthesized using Terminalia Terminalia cuneatacuneata
4000 3500 3000 2500 2000 1500 1000 5000
20
40
60
80
% T
Wavenumber (cm-1)
A B
3385
1625
1440
1383
1050
30 40 50 60 70 80
0
1000
2000
3000
4000
5000
6000
7000
Cou
nts
2
38.2 (1 1 1)
44.5 (2 0 0)
64.5 (2 2 0)
77.6 (3 1 1)
FT-IR spectra of AgNPs synthesized by T. cuneata extract
XRD pattern of AgNPs synthesized by T. cuneata extract
Characterization of AgNPs synthesized using Characterization of AgNPs synthesized using Terminalia Terminalia cuneatacuneata
HR-TEM images of synthesized AgNPS using T. cuneata (Average size 40 nm)
Characterization of AgNPs synthesized using Characterization of AgNPs synthesized using Terminalia Terminalia cuneatacuneata
Na+
Na+
SO
O
-O
SO
OO-
N
NO
N
N O
Disodium 4,4'-bis[(4-ethoxyphenyl)azo]stilbene-2,2'-disulphonate
H2
H2
H2
H2
NaBH4
AgNPs
NH2O
2
Na+
Na+
SO
O
-O
SO
OO-
NH2
NH2
Disodium (E )-6,6'-(ethene-1,2-diyl)bis(3-aminobenzenesulfonate)4-ethoxyaniline
Catalytic action of AgNPs synthesized using Terminalia cuneata on the reduction of Direct Yellow 12
300 400 500
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Abs
orba
nce
Wavelength () (nm)
Initial
5 mins
10 mins
40 mins
.
.
.
Degradation of Dirct Yellow-12 by AgNPS synthesized by T. cuneata follow Langmuir-Hinshelwood model
OH
OH
HO O
OH
OH
Catechin
OH
OH
HO O
OH
OH
Epicatechin
OOH
HO O
OH
Apigenin
O
O
HO
HO
Methyl 3,4-dihydroxybenzoate
O
O
HO
HO
3,4-dihydroxyphenyl acetate
O
OH
O
OH
HO
OH
OH
OH
OH
OH
HOOH
Procyanindin B2
OHO
OH
OH
OOH
OH
Taxifolin
Tamarindus indica
Phytoconstituents of T. indica seed coat
Synthesis of AgNPs using Synthesis of AgNPs using Tamarindus indicaTamarindus indica(Submitted to Spectroscopy Letters)
200 300 400 500 600 700 8000.00
0.05
0.10
0.15
0.20
0.25
Abs
orba
nce
Wavelength ( (nm))
0.10 ml (437 nm) 0.25 ml (437 nm) 0.50 ml (437 nm) 1.00 ml (439 nm) 2.00 ml (441 nm)
200 300 400 500 600 700 8000.0
0.1
0.2
0.3
0.4
0.5
Abs
orba
nce
Wavelength ( (nm))
0.10 ml (441 nm) 0.25 ml (432 nm) 0.50 ml (434 nm) 1.00 ml (438 nm) 2.00 ml (aggregated)
200 300 400 500 600 700 8000.00
0.05
0.10
0.15
0.20
0.25
0.30
Abs
orba
nce
Wavelength () (nm)
433 nm 432 nm 428 nm 423 nm 414 nm
pH - 5
pH - 6
pH - 7
pH - 8
pH - 9
200 300 400 500 600 700 8000.0
0.5
Abs
orba
nce
Wavelength ( (nm))
448 nm 430 nm 428 nm 419 nm 398 nm & 555 nm
pH - 7
pH - 6
pH - 5
pH - 8
pH - 9
Synthesis of AgNPs at 10 min using T. indica Synthesis of AgNPs at 24 h using T. indicaEffect of pH on AgNPs synthesis – at 10 min Effect of pH on AgNPs synthesis – at 24 h
Red shift – Size increases
Blue shift – Size decreases
Red shift – Size increases
Blue shift – Size decreases
Characterization of AgNPs synthesized using Characterization of AgNPs synthesized using Tamarindus Tamarindus indicaindica
4000 3500 3000 2500 2000 1500 1000 500
60
80
100
120
% T
Wavenumber (cm-1)
3417
3409
29192850
29212863
1619
1635
1384
1112
1112A
B
FT-IR spectra of AgNPs synthesized by T. indica extract
HR-TEM images of synthesized AgNPS using T. indica (30 nm) Spherical
Characterization of AgNPs synthesized using Characterization of AgNPs synthesized using Tamarindus Tamarindus indicaindica
10 20 30 40 50 60 700
500
1000
1500
2000
2500
3000
Cou
nts
2
38.23 (111)
44.62 (200)
64.51 (220)
XRD patterns of AgNPs synthesized by T. indica extract DLS (30 nm) Zeta potential (-35 mV) of AgNPs synthesized by T. indica
200 300 400 500 600-0.2
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
Abs
orba
nce
Wavelength () (nm)
412 nm282 nm
224 nm
300 400 500 6000.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
Initial 2 min 5 min10 min15 min30 min35 min40 min45 min
Abs
orba
nce
Wavelength () (nm)
394 nm
380 nm282 nm
UV-Vis spectra of 2–nitro aniline Reduction of 2–nitro aniline by AgNPs synthesized by T. indica
Characterization of AgNPs synthesized using Characterization of AgNPs synthesized using Tamarindus Tamarindus indicaindica
O
OH
O
O
HO
Syringic acid
OHO
HO
p-coumaric acid
O
OH
OH
HOOH
OH
OH
Epigallocatechin
Anacardium occidentale Anacardium occidentale –seed coat
Phytoconstituents of Anacardium occidentale
Synthesis of AgNPs using Synthesis of AgNPs using Anacardium occidentaleAnacardium occidentale(Revision submitted to Process Biochemistry)
•Red shift was observed at different times
•Particle size increased with increase of concentration of extract
Effect of Concentration of Extract
Blue shift – Size decreases
Characterization of AgNPs synthesized using Characterization of AgNPs synthesized using Anacardium Anacardium occidentaleoccidentale
UV-Vis spectroscopy
Effect of pH•Blue shift was observed at different times
•Particle size decreased with change of pH from acidic to basic
4000 3500 3000 2500 2000 1500 1000 5000
20
40
60
80
100
% T
rans
mitt
ance
Wave Number (cm-1)
A. occidentale extract AgNPs synthesized using A. occidentale
3395
2925
1614
1519
1450
1384
1143
835
A
B
10 20 30 40 50 60 70 800
200
400
600
800
1000
1200
1400
Cou
nts
2
Ag (111)
Ag (200)
Ag (220)
HR-TEM images of synthesized AgNPS using A. occidentale (40 nm)
FT-IR spectra of AgNPs synthesized by A. occidentale extract XRD pattern of AgNPs synthesized by A. occidentale extract
Characterization of AgNPs synthesized using Characterization of AgNPs synthesized using Anacardium Anacardium occidentaleoccidentale
Electrode Potential (V) Current density × 10-5 (A)
GC 0.73 2.12
Bulk silver 0.69 2.98
GC/AgNPs 0.60 5.03
Cyclic voltammogram of electrocatalytic oxidation of hydrazine hydrate in K2SO4 at GC, bulk silver and GC
modified AgNPsVoltammeteric data for the oxidation of hydrazine at GC,
bulk silver and GC/AgNPs in K2SO4
Negative shift of oxidation potential indicates the catalytic activity of biogenic AgNPs
Electrocatalytic oxidation of hydrazine hydrate by AgNPs
N2H4 + H2O N2H3 (ads) + H3O+ + e-
N2H3 (ads) 3H2O+ N2 3H3O++ 3e-+
OHO
OH O
OH
OCH3
OH
Isorhamnetin
OH
OOH
HO O
OH
OH
Quercetin
OH
OH
HO O
OH
OH
(+)-Catechin
OH
HO
OH
Resveratrol
O
HO
O
OH
Ferulic acid
O
OH
O
OH
Vanillic acid
Areca catecheu
Chemical constituents present in the Areca catechu nut
Synthesis of AgNPs using Areca catechu nut
(Submitted to Spectrochimica Acta A)
Characterization of AgNPs synthesized using Areca catechu nut
Average particle size 40 nm
Electrode Potential (V) Current density × 10-4 (A)
GC 1.29 1.77
Bulk silver 0.71 2.39
GC/AgNPs 0.52 4.14
CV of electrocatalytic oxidation of glucose in NaOH at GC, bulk silver and GC modified AgNPs CV data of oxidation of glucose at GC, bulk silver and
GC/AgNPs in NaOH
Electrocatalytic oxidation of glucose in NaOH
CO H
OHR
OH-
CO
ROH + H+ + e-
CO
ROH
OH-
CO
RO + H+ + e-
H2OR'COOH
Negative shift of oxidation potential indicates the catalytic activity of biogenic AgNPs
Synthesis of silver Synthesis of silver nanoparticles using nanoparticles using
microorganismsmicroorganisms Synthesis of silver nanoparticles using Penicillium fungi, Bacillus strain, Synthesis of silver nanoparticles using Penicillium fungi, Bacillus strain,
marine bacterium (Idiomarina sp. PR58-8) Pseudomonas fluorescens has marine bacterium (Idiomarina sp. PR58-8) Pseudomonas fluorescens has also been reported. also been reported.
The extracellular mechanism of silver nanoparticle creation was The extracellular mechanism of silver nanoparticle creation was investigated by regular methods viz., UV-Vis spectroscopy, FT-IR, TEM, DLS, investigated by regular methods viz., UV-Vis spectroscopy, FT-IR, TEM, DLS, zeta potential and XRDzeta potential and XRD
Irradiation methodsIrradiation methods
Laser ablation methodLaser ablation method Microwave irradiationMicrowave irradiation Sun light exposureSun light exposure
– Highly stable nanoparticlesHighly stable nanoparticles– High purityHigh purity
Other Applications of biogenic Other Applications of biogenic nanoparticlesnanoparticles
Antibacterial agentsAntibacterial agents Antiviral agentsAntiviral agents Anti-oxidantsAnti-oxidants Anti biofilm Anti biofilm Larvicidal agentsLarvicidal agents Disinfection of waterDisinfection of water Decrease of biofoulingDecrease of biofouling Wettability of hairWettability of hair
•All the plant extracts chosen for the present study act as good reducing agents and protecting
agents for the formation and stabilization of AgNPs.
•Upon increasing the concentration of the chosen plant extracts, the size of AgNps increased,
as evident from the results of UV-Vis spectroscopic studies.
•In the AgNPs synthesis, pH played a crucial role to control the size and shape of AgNPs.
•In neutral pH, the synthesized AgNPs are highly stable when compared with other pH ranges.
Moreover, the sizes of the AgNPs were decreased on changing the pH from acidic to basic in
the case of studied extracts.
•The synthesized AgNPs using all the chosen plant extracts were found to have the absorbance
in the wavelength of 400-450 nm which suggested the spherical shape of biogenic AgNPs.
ConclusionsConclusions
•The phytoconstituents (mainly tannins and polyphenols) present in all the studied
plant extracts were responsible
for reduction of Ag+ and protection of AgNPs which was analyzed by FT-IR studies.
•The average size distribution of AgNPs (synthesized using all the extracts) was
found to be 20-50 nm in size as studied using DLS measurement.
•The high negative zeta potential (~30-40 mV) of synthesized AgNPs suggested the
high stability.
•HR-TEM and EDS profile corroborated the results of DLS studies
ConclusionsConclusions
To ConcludeTo Conclude
It is true that there is plenty of room It is true that there is plenty of room at the bottom at the bottom
Future will see Biogenic Future will see Biogenic nanotechnology in Medicine, nanotechnology in Medicine, Environment and other domainsEnvironment and other domains
Thank UThank UOlny post by Maruthupandi M Indian-TN-MDU