This document discusses the evaluation of the antimicrobial activity of ZnO nanoparticles. It begins with an introduction to nanoparticles and their size-dependent properties. It then reviews literature on the various applications of nanoparticles in biomedical, environmental, and industrial fields. Specifically, it discusses how ZnO nanoparticles have shown antibacterial effects against various microorganisms. The document concludes by outlining several references used in the literature review.

1. EVALUATION OF ANTIMICROBIAL ACTIVITY OF ZnO
NANOPARTICLE
A Dissertation submitted in partial fulfillment of the requirements for the
degree of
Bachelor of Technology
In
Biotechnology
By
Ashwani Pratap Yadav
Roll No. 1000154020
Under the supervision of
Er. Kritika Tiwary
Anand Engineering College, Agra
Agra-282002, Uttar Pradesh, India
August 2013

2. INTRODUCTION
Nanoparticle research is currently an area of intense scientific research, due to a wide variety of
potential applications in biomedical, optical, and electronic fields. Nanoparticles are of great scientific
interest as they are effectively a bridge between bulk materials and atomic or molecular structures.
A bulk material should have constant physical properties regardless of its size, but at the nano -scale
this is often not the case.
Size-dependent properties are observed such as quantum confinement in semiconductor particles,
surface plasmon resonance in some metal particles and superparamagnetism in magnetic materials. The
properties of materials change as their size approaches the nanoscale and as the percentage of atoms at
the surface of a material becomes significant.
For bulk materials larger than one micrometre the percentage of atoms at the surface is minuscule
relative to the total number of atoms of the material.
The interesting and sometimes unexpected properties of nanoparticles are not partly due to the aspects
of the surface of the material dominating the properties in lieu of the bulk properties. Nanoparticles
exhibit a number of special properties relative to bulk material
● Definitions
Definition by size
- Particles having sizes less than 0.1 (100nm)
1st generation nanoparticles: <100nm
2nd generation nanoparticles: <10nm
- Lower limit of nanoparticles: ~1nm
Other names of nanoparticles
- ultrafine particles, clusters, nanocrystals, quantumdots
colloids, aerosols, hydrosols, organosols..
Size Ranges of Particle
- Coarse particles : >10_m
- Fine particles : ~1 _m
- Ultrafine (nano) particles : <0.1 (100nm)
Definition by properties
: whose properties becomes discontinuous as the bulk contracts
- less than the characteristic length of some phenomena
Mean free path of gases, wavelength of light, electron wave,
distance between electro-hole pair (exciton)
Characteristics of nanoparticles
-Difficult to produce by breakdown process:
-Formation by growth (buildup or bottoms-up)
-Small size effect (quantumsize effect)
-Contain very small number of atoms(or molecules): size effect
-Electronic states quite different from those of bulk: size effect
-Large surface effect
- Contain large portion of surface atoms(or molecules) : High surface

3. activity
● Field of Nanoparticle Technology
(1) Design and preparation of nanoparticles with high functionality
Properties which are modified:-
Size, shape, chemical properties, crystallinity, structures if composites
Tech. to modify above properties :-
Bottom-up: nucleation and growth in liquid phase and/or gas phase
Top-down: ultrafine milling
Mixed: spray pyrolysis in aerosol phase
(2) Characterization of nanoparticles
Size and morphology(shape): TEM (Transmission electron microscopy), SEM (Scanning Electron
microscopy), STM , LPA, DMA
Chemical/crystalline properties: FT-IR, NMR, ACP-IES, XRD
Surface properties: BET, XPS, Auger, AFM
Composite structures: TEM, element mapping
(3) Dynamics of nanoparticles
- Movement of nanoparticles
- Formation and growth of nanoparticles
(4) Handling (Unit Operation) of Nanoparticles
- Storage, transport, crushing and mixing
- Separation
(5) Dispersion, Consolidation and Device (Value Addition) Technology
- Particle-particle interaction
- Surface modifications
- Assembly: 1-, 2-dimensional, porous, densification
- Device for application
(6) Adverse Effect of Nanoparticles
- Dust explosions
- Respiration hazards/Effect in human bodies
- Particle contamination and cleaning in industries
Anti-bacterial activity
Antibacterial activity is basically the capability of a substance/compound to destroy the bacteria or to
suppress the growth and reproduction of the bacteria. The compound may be a drug or plant/animal
extract or some metal oxides (like ZnO). We are going to use nano particle for the estimation of anti-
microbial activity.
REVIEW OF LITERATURE
Despite views that nanotechnology is a far-fetched idea with no near-term applications, nanoparticles,
nanopowders and nanotubes already play a significant role in industry, environmental remediation,
medicine, science and even in the household. The majority of nanotechnologies commercially used
today are based on such nano-sized particles. Rare earth nanoparticles and rare earth oxide
nanopowders are finding application in uses as varied as enhanced fiber optic amplification (EDFA) to
the removal of phosphate in the blood of patients with Hyperphosphatemi (R.G . Osifchinm et al.,
1996). Iron Nanoparticles, Iron Oxide Nanopowder, Cobalt Nanoparticles, and several other elemental

4. nanoparticles and alloys form a group of "Magnetic Nanoparticles" with promising application in
medical treatment of cancer, magnetic storage and magnetic resonance imaging (MRI) (G.Schmid et
al., 1992).
The biomedical and bio-science fields have found near limitless uses for nanoparticles. Nanoparticles
made of peroxalate ester polymers with a fluorescent dye (pentacene) encapsulated into the polymer
have been found to be capable of detecting cancer (Y.Z. Huang et al, 1993). This is due to the fact that
hydrogen peroxide is generated in human cells that are precancerous. The dye in the nanoparticles
fluoresces when they come in contact with the hydrogen peroxide which can then be detected as
light on medical imaging equipment. Artificial bone composites are now being manufactured from
calcium phosphate nanocrystals (H. Liedberg et al, 1987).These composites are made of the same
mineral as natural bone, yet have strength in compression equal to stainless steel. Tungsten Oxide
Nanoparticles are being used in dental imaging because they are sufficiently radiopaque (impervious to
radiation) for high quality X-ray resolution (M. Ge,B.Zhong et al., 2001). The group of Magnetic
Nanoparticles discussed above is being used to both kill cancer cells in malignant tumors and in MRI
medical imaging. Coat tungsten particles with DNA and inject them into plant cells or plant embryos.
Some genetic material will remain in the cells and transform them. This method allows transformation
of plant plastids. The transformation efficiency is lower than in agro bacterial mediated transformation.
The anti-bacterial and antimicrobial effects of many nanoparticles are well understood technology.
Fluorescent nanoparticles are being used by biologists to stain and label cellular components (E.
Papaconstantinou et al., 2002). By changing the size of the quantum dot the color emitted can be
controlled. With a single light source, one can see the entire range of visible colors, an advantage over
traditional organic dyes. While there has been news of the possible environmental effects of
nanotechnology, such as predictions of "gray goo" formation, to date Nanotechnology has been the
source of several environmental cleanup products. For example, Nickel Nanocrystals are a reagent for
the dehalogenation of trichloroethylene (TCE) , a common groundwater environmental remediation
contaminant (Lan Y QuJ et al, 2006). Nanotechnology is expected to open some new aspects to fight
and prevent diseases using atomic scale tailoring of materials. The ability to uncover the structure and
function of biosystems at the nanoscale, stimulates research leading to improvement in biology,
biotechnology, medicine and healthcare. The size of nanomaterials is similar to that of most biological
molecules and structures; therefore, nanomaterials can be useful for both in vivo and in vitro
biomedical research and applications. The integration of nanomaterials with biology has led to the
development of diagnostic devices, contras agents, analytical tools, physical therapy applications, and
drug delivery vehicles. In all the nanomaterials with antibacterial properties, metallic nanoparticles are
the best. Nanoparticles increase chemical activity due to crystallographic surface structure
with their large surface to volume ratio. The importance of bactericidal nanomaterials study is because
of the increase in new resistant strains of bacteria against most potent antibiotics. This has
promoted research in the well known activity of silver ions and silver-based compounds, including
silver nanoparticles. This effect was size and dose dependent and was more pronounced against gram-
negative bacteria than gram-positive organisms (Salopak- Sondi et al , 2004). The re-emergence of
infectious diseases poses a serious threat to public health worldwide, and the increasing rate of the
appearance of antibiotic-resistant strains in a short period of time within both Gram-positive and Gram-
negative microorganisms is a major public health concern. Alternative therapeutics to control and
prevent the spread of infections in both community and hospital environments are required Although
various classes of antibiotics (penicillin and derivatives) were discovered in 1940s and 1950s, in the
past 40 years only two antibiotics representing new chemical classes (namely linezolid and
daptomycin) have reached the market to treat multiple antibiotic – resistant Gram-positive infections.
Recent advances in the fields of nanotechnology, particularly the ability to prepare highly ionic metal
oxide nano particulates of any size and shape, may lead to the development of new antibacterial agents
(Lowy et al, 1998). It is is found that nearly all the nonoparticles have toxicological and antibacterial
effect on a wide range of micro organisms (Koper et al., 2002). Mostly Silver, Zinc oxide, Cesium etc
nano particles show very good effects in low concentrations ranging from 10μg/ml to 200μg/ml.
Besides it is also found that nano particle size and structure and purity also plays very important role in
its bactericidal effect. Although metals and metal oxides such as ZnO are known to be toxic to host
human cells at relatively high concentrations, they are not expected to be toxic at very low
concentrations (Tiller et al., 2001). In fact, it has been shown that ZnO protects against intestinal
diseases by protecting intestinal cells from E.coli (ETEC) infection by inhibiting the adhesion and
internalization of bacteria Therefore, substantial bacterial grow that lower concentrations of ZnO
suggest that ZnO nano particles may not be toxic for various. The nano particles mainly form pits on

5. the cell membrane of micro organisms by disintegration the protein structure and deposit in the pits.
This causes the death of the organism. In a study about mechanistic action of nano particles
(Zinc Oxide was used), ZnO induced toxicity in cells, leading to the generation of reactive oxygen
species (ROS), oxidant injury, excitation of inflammation, and cell death. (Roselli et al., 2003).
Nanoparticle metal oxides represent a new class of important materials that are increasingly being
developed for use inresearch and health-related applications .Highly ionic metal oxides are interesting
not only fortheirwide variety of physical And chemical properties but also for their antibacterial
activity .Although the invitro antibacterial activity and efficacy of regular zinc oxides have been
investigated, little is known about the antibacterial activity of nanoparticles of ZnO. Preliminary
growth analysis data suggest that nano particles of ZnO have significantly higher antibacterial effects
on Staphylococcusaureus than do five other metal oxide nano particles (Zaoutis et al., 2006). In
addition, studies have clearly demonstrated that ZnO nanoparticles have a wide range of antibacterial
effects on a number of other .The antibacterial activity of ZnO may be dependent on the size and the
presence of normal visible light (Tiller et al., 2001;Lin e tal.,2002;Stoimenov et al.,2002;Kuhn et
al.,2003;Sawai,2003;Sunada et al.,2003;Sondi & Salopak-Sondi,2004;Lewis&Klibanov,2005;Rosi&
Mirkin,2005;Ma et al.,2006;Thill et al.,2006). The data suggest that ZnO nanoparticles have a potential
application as a bacteriostatic agent invisible light and may have future applications in the development
of derivative agents to control the spread of bacteria. Each organisminherits its DNA from its parents.
Since DNA is replicated with each generation, any given sequence can be passed on to the next
generation. An RFLP is a sequence of DNA that has a restriction site on each end with a "target"
sequence in between. A target sequence is any segment of DNA that bind to a probe by forming
complementary base pairs. A probe is a sequence of single-stranded DNA that has been tagged with
radioactivity or an enzyme so that the probe can be detected. When a probe base pairs to its target, the
investigatorcan detect this binding and know where the target sequence is since the probe is detectable.
RFLP produces a series of bands when a Southern blot is performed with a particular combination of
restriction enzyme and probe sequence (Gaballa & Helmann,1998;Lindsay&Foster,2001).
APPLICATION
● On the basis of state:-
Dispersed state
Fillers, paints, ferrofluids, magnetic recording media, drugs, cosmetics,
phosphors, rocket propellant, fuel additives
Consolidated state
- Porous structure
Catalysts, electrodes of solar cells and fuel cells, sensors, adsorbents,
synthetic bone, self-cleaning glass
- Ordered assembly
Quantum electronic device, photonic crystals, DNA chips, biosensors
- Dense phase
Flexible/dense ceramics and insulators, harder metal, CNT in tennis
Racquet
● On the basis of fields are:-
Biomedicals
- Pharmacy in a cell- controlled release
- Solubilized therapeutic drugs
- Tagging of DNA and DNA chips
Information Tech
- Information storage (nanoparticles, nanopens)
- Chemical/Optical computers(2-D,3-D assembly- photonic crystals)
- Quantum (molecular) electronic devices
Materials
- Flexible/dense ceramics and insulators: replacing metals
- Harder metal materials(5 times that of normal metals)

6. - Nanometallic colloids as film precursors
- Fillers for improved polymers (stronger, lighter, wear resistant, tougher lame
retardant) - replacements for body parts and metals
- Unusual coloring in paints
- Smart magnetic fluids (vacuum seals, viscous dampers, cooling fluids, nanoscale
bearings, heat conductors, magnetic separations)
Energies
- Magnetic refrigeration (magnetocaloric effect)
- Nanostructured electrodes and magnetic metals with soft magnetic properties
- Better batteries- metal nanoparticles
Environmental/green chemistry
- solar cells (photovoltaic, water splitting)
- photo-remediation (pollutant destruction, water decontamination)
- Destructive adsorbents (acidic gases, polar organics)
- Self cleaning
Catalysis
- Chemical catalysts (particle size and dispersion, crystal faces, edges, corners,
defects)
-Sensors (porous aggregates of semiconductor particles)
REFERENCES:-
• AB. Roy VAL, Djuris and Chan WK, Gao J, LuiHF, Surya C .2003. Luminescent and structural
properties of ZnO nanorods prepared under different conditions. Appl Phys Lett 83:141–143.
• B.Doungporn Yiamsawas, Kanittha and Wiyong
Kangwansupamonkon .2009. Preparation of ZnO
Nanostructures by Solvothermal Method, Journal of
Microscopy Society of Thailand 23(1):75-78.
• Coleman V.A. and C. Jagadis.2006. Basic properties and
applications of ZnO,
• EA.Meulenkamp.1998. Synthesis and growth of ZnO
nanoparticles. J Phys Chem B 102:5566–5572.
• G.Priyanka. and Brain Peltee David W Brill, Wenjie
Huang, William P Johson and Anne J Aderson. 2009.
Antimicrobial activities of commercial Nanoparticles
against an environmental Soil microbe, Pseudomonas
Putida KT2440, Journal of Biological engineering 3:9
• G. Kodihalli. and Chandrappa.2009. A Hybrid
Electrochemical-Thermal Method for Preparation of
Large ZnO Nanoparticles. J Nanopart Res, 10.1007
ii
• G.Hengxiang. and Yunyao H, Qifeng W, Guojuan J, Zebo
F, Yinyue W .2004. Polycrystalline ZnO films deposited
on glass by RF reactive sputtering. Semicond Photonics
Technol. 10(2):97–10
• Hui Li .2009. Effects of In and Mg doping on
properties of ZnO nanoparticles by flame spray synthesis,
Journal Nanopart Res, 11:917–92.
• J Nicole. and Binta ray.koodali T. ranjit Adhar
C.mana.2007 .Nanoparticles suspension on a broad
spectrumof micro organism. FEMS
• K. Jong Pil .2010. Characteristics of ZnO Nano-Crystals
Grown on Al-doped ZnO Thin Films Deposited by using
the PLD Method, Journal of the Korean Physical Society,
56: 378-382

7. • L.Vayssieres.2003. Growth of arrayed nanorods and
nanowires of ZnO from aqueous solutions, Adv Mater.
15:464–466.
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