nanomaterial presentation

8/11/2019 NANOMATERIAL PRESENTATION

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GRAPHENE MODIFIED NANOPOROUS

MEMBRANE BASED

NANOIMMUNOSENSOR FOR THE

SELECTIVE DETECTION OF CANCER

BIOMARKERS

SPEAKER-

ID.NO. -


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CONTENTS


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CONTENTS

INTRODUCTION TO BIOSENSOR

BIOSENSOR AND NANOTECHNOLOGY

BIOSENSOR AND CANCER

OBJECTIVES

CONCLUSION


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WHAT IS BIOSENSOR?

BIOSENSOR IS A SENSING DEVICE WHICH CAN

CONVERT A BIOLOGICAL RESPONSE INTO AN

ELECTRICAL SIGNAL.

THE NAME BIOSENSOR SIGNIFIES THAT THE

DIVECE IS A COMBINATION OF TWO PARTS :

1. BIOELEMENT

2. SENSOR - ELEMENT


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Components of biosensor

Fig. 1 Configuration of a biosensor showing biorecognition,

interface, and transduction elements.


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Principle of detection

A specific bio element recognizes a specificanalyte.

The sensor element transduces the change in the

biomolecule into an electrical signal that can beamplified, displayed, and analyzed.

The bioelement may be an enzyme, antibody, living

cells, tissue, etc. The sensing element may be electric current,

electric potential, intensity, mass, conductance,

impedance, temperature and so on.


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Kinds of biosensor

Electrochemical biosensor

Optical biosensor

Piezoelectr ic biosensor

Calor imetr ic biosensor


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History of biosensor development

Prof Leyland C Clark in 1956 - published his definitive paper onthe oxygen electrode.

In 1962 Clark and Lyons - enzyme electrode.

In 1969development of first potentiometric biosensor.

In 1974 - the use of thermal transducers for biosensors.

In 1975 - Divis suggested that bacteria could be used as the

biological element in microbial electrodes .


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Cont..

Since the early 1970 - building of immunosensor.

Peterson in 1980 - First fibre optic pH sensor.

In 1982 - First fibre optic-based biosensor for glucose detection.

In 1983 - First surface plasmon resonance (SPR) immunosensor.

In 1984 - First mediated amperometric biosensor.


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APPLICATION OF BIOSENSOR

P o i n t o f c a r e d i a g n o s t i c s .

B a c t e r i o lo g i c a l d e t e c t i o n

I n M e d i c a l C a r e

F o r d e t e r m i n at i o n o f f o o d q u a l i t y

E n v i r o n m e n t a l m o n i t o r i n g .

F o r I n d u s t r i a l P r o c e s s C o n t r o l .


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If I want to measure

something small, I

need something

small


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BIOSENSOR AND NANOTECHNOLOGY

Nanotechnology will enable us to design

sensors that are :

much smaller

less power hungry

more sensitive


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What Is Nanotechnology?

Richard Feynmans

(1918-1988)

A nanometre is 1/1,000,000,000 (1 billionth) of a metre, which is around

1/50,000 of the diameter of a human hair or the space occupied by 3-4 atomsplaced end-to-end.

A few carbon atoms on the

surface of highly oriented

pyrolytic graphite (HOPG). Image

obtained by Scanning Tunneling

Microscope (STM).

nanotechnology is a field to understand, create, and

use structures, devices and systems that have

fundamentally new properties and functions because

of their nanoscale structure.


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Tools In Nanotechnology

The main tools used in nanotechnology are four

main microscopes

1Transmission Electron Microscope (TEM)

2Atomic Force Microscope (AFM)

3Scanning Tunneling Microscope (STM)

3Scanning Electron Microscope (SEM)


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NANOMATERIALS Nanostructured materials have been successfully used in the last

years for the construction of fast, accurate and sensitive sensors as

they have excellent properties.

Carbon nanotubes, nanowires, and nanochannels, Quantum dots,

nanoparticles are all examples of nanomaterials.

(The small size of allows for a greater surface to volume ratio)

Carbon

nanotubes

Fullerene

Dendrimers


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Nanostructures Map


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Graphene oxide

Graphite when treated with strong oxidizers gives rise to the Graphite oxide,

which is a compound of carbon, oxygen, and hydrogenin variable ratios.

Manufacture of Graphene Oxide

Graphene Oxideis formed by oxidizing crystalline graphite with a mixture of

sodium nitrate (NaNO3 , sulfuric acid (H2SO4),and potassium permanganate(KMnO4).The oxidation method is also known as the Hummers method.

Structurally, the Graphene Oxideis similar to a graphene sheet with its base

having oxygen-containing groups. Since these groups have an high affinity to

water molecules, Graphene Oxideis hydrophilic and can be easily dissolved in

water.
http://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Hydrogenhttp://www.azonano.com/ads/abmc.aspx?b=5265http://www.azonano.com/ads/abmc.aspx?b=5265http://www.azonano.com/ads/abmc.aspx?b=5265http://www.azonano.com/ads/abmc.aspx?b=5265http://www.azonano.com/ads/abmc.aspx?b=5265http://www.azonano.com/ads/abmc.aspx?b=5265http://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Carbon


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Cont

Graphene Oxideis a poor conductor but when it undergoes treatment using

heat, light, or chemical reduction, most of graphene's properties are restored.

Chemical reduction is normally done using hydrazine.

It is possible to deposit Graphene Oxidefilms on any substrate, and then

convert it into a conductor. These coatings may be used in solar cells, flexible

electronics, chemical sensors, liquid crystal devices

Graphene, which is a conductor, graphene oxide is a semiconductors and can

replace silicon in electronics applications.
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cont..

Applications of Graphene Oxide

Graphene oxidefinds application in the

following fields:

Transparent conductive films

Paper-like and composite materials

Energy-related materials Biological and medical applications.
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Graphene

Graphene, is one of the allotropic forms of carbon.

It is a one-atom-thick planar sheet of carbon atoms that are densely packed in a honeycombcrystal lattice.

Graphite itself consists of many graphene sheets stacked together.

The carbon-carbon bond length in graphene is approximately 0.142 nm.


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Graphene production

Researchers obtained relatively large graphene sheets bymechanical exfoliation (repeated peeling) of 3D graphitecrystals.

Another method is to heat silicon carbide to high temperatures(1100C) to reduce it to graphene.

Graphene has excellent properties like:

Its entire volume is exposed to its surrounding.

High electrical conductivity.


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Nanofabrication methods


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BIOSENSOR AND CANCER

Cancer is an abnormal and an uncontrolled cell growth

due to an accumulation of specific genetic andepigenetic defects.

Biosensor technology has the potential to provide: fast and accurate detection.

reliable imaging of cancer cells.

monitoring of angiogenesis and cancer metastasis.

ability to determine the effectiveness of anticancer

chemotherapy agents.


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Preexisting technology

Existing cancer screening methods include:

(1) the CA 15.3 test and mammography to detect breast

cancer in women.

(2) prostate-specific antigen (PSA) level detection in blood

sample for men to detect prostate cancer.

(3) blood detection for colon cancer.

(4) endoscopy, CT scans, X-ray, ultrasound imaging andMRI for various cancer detection.


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Cont

These traditional diagnostic methods however

are not very powerful methods :-

as they can not detect cancer at very early

stages.

some of the screening methods are quite costly

and not available for many people.

so use of biosensors to detect cancer biomarkers

in serum has spread widely.


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Biomarkers

In terms of cancer, the analyte being detected by

the biosensor is a tumor biomarker.

A biomarker is an indicator of a biological state of

disease.

Biomarkers can be DNA, RNA, or protein (i.e.,

hormone, antibody, oncogene, or tumor

suppressor).


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OBJECTIVES

Surface modification of nanoporous membrane by

graphene oxide

Characterization of graphene coated nanoporous

membrane by SEM

Immobilization of antibody on nanoporous membrane

Characterization of immobilized nanoporous

membrane.

Fabrication of nanoimmunosensor.

Detection of sample.

Standardization of protocol of nanoimmunosensors


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Surface modification of nanoporous

membrane by graphene oxide

(1)Coating of the graphene oxide onto the

nanoporous membrane by drop coating method.

Drop wise graphene is poured onto the membrane.

A thin film is obtained onto the membrane surface.


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CH R CTERIZ TION OF GR PHENE CO TED

MEMBR NE BY SEM

The membranes categorized in two different classes-

(1) PCTE membrane was used as such

(2) PCTE membrane coated with graphene nanolayer over

the one surface of membrane with the help of drop coating

method.


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Functionalization of graphene

modified membrane


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cont...

Graphene is incubated with linker molecule in

dimethylformamide (DMF).

The linker-modified graphene then incubated with

antibody in Na2CO3-NaHCO3 buffer solution (pH 9.0)

overnight at 40

C, followed by rinsing with DI water andphosphate buffered saline solution (PBS).

Raman spectroscopy in particular has been found to be a

valuable tool to elucidate the structural properties of

graphene.


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Cont

Fig. 1 (A) Raman map and spectrum of graphene film. The map isconstructed by plotting the peak width at half height of the 2D-band as

the pixel intensity. Scale bar 0.8 mm. (B) AFM image of the graphene

film. Scale bar 500 nm.

This journal is The Royal Society of Chemistry 2011 J. Mater.


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CHARACTERIZATION OF IMMOILIZED GRAPHENE

Electron microscopy (TEM and SEM) and

atomic force microscopy have been used to

characterize the graphene.


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ST ND RDIZ TION OF PROTOCOL OF

N NOIMMUNOSENSOR

(A)Recording of amperometric data.

(B)Digitalization of signals and recording.


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CONCLUSION


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conclusion

In present work a graphene modified PCTE (polycarbonate Track

Etch)membrane is used in nanoimmunosensors which can be employed todetect specific cell membrane-associated target antigens.

The morphology of graphene modified nanoporous membrane was

characterized by Scanning Electron Microscopy and chemical analysis was

completed by FTIR (Fourier Transform Infrared Spectroscopy) prior to use in

nanobiosensor.

This antibody immobilized membrane structure was then tested with a no.

of few antigens and cross checked by structurally related antigens for

specificity.


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