پاورپوینت بیوسنسورهای بر پایه گرافن به زبان انگلیسی

Graphene Based Biosensors
By Fatemeh Khaleghi

Dr.yousefpour

Semnan University
Shahrivar 1392
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What is a biosensor?
Man-made biosensors
Disease Diagnostic
Security
A device for detecting biological compounds
2

Construction of a biosensor
Biological element
transducer
Processing system
Enzymes

Nucleic acids

Abtibodies

Cells

Biomimetic materials
Electrochemical

Optical

Piezoelectric

Calorimetric

Processor

Amplifier

Screen
3

Biological element

Enzymes

Nucleic acids

Antibodies
Cells
Biomimetic materials
Different Types of Biosensors
4

Different Types of Biosensors
Transduction systems

Electrochemical

Optical
Piezoelectric
Calorimetric
conductometric
amperometric
potensiometric
V
I
Luminescent emmission
Reflection
Absorption
5

Performance of a biosensor
Linear range
Signal to noise ratio
Selectivity
Sensitivity
Limit of detection
6

Graphene
The lightest
The most conducting
More strength than even diamond
flexible
Tunable band gap
transparent
A new material for biosensing
7

Graphene Based Electrochemical biosensors
Electrode
It does not contain impurities
It is made of graphite
It has a large density of edge-plane-like defects
It is the most conducting material
It has a large surface area
It has an antifouling property
It naturally contains functionalized groups
8

A typical cyclic voltammogram of graphene
Zhou et.al
Comparable potential window with GC and graphite, while better ET
9

Graphene Based Electrochemical biosensors
CNT
10

Graphene Based Electrochemical biosensors
neurotransmitter
Different molecular structure
11

Graphene Based Electrochemical biosensors
enzymatic
Non-enzymatic
For detection of:
-glucose
-NADH
-Hb
-HRP
-cholestrol
Disadvantages:
-instability
-high price
-complex immobilization techniques
-be affected by pH, temperature

For detection of:
-H2O2
-AA
-DA
-UA

12

Graphene field effect transistors
Field Effect
13

Graphene field effect transistors
Charge entrapment in SiO2
Problem
Suspending of graphene
Solution
×
14

Graphene field effect transistors
15

Graphene based optical biosensors
2D nature
Raman activity
Flourscence Resonance Energy Transfer
tranparency
Tunable optical properties
Optical biosensors
16

Biocompatibility of Graphene biosensors
Chang et al
GO hardly enters cells and shows good biocompatibility
Liu et al
Good adhesion of ARPE cells showing excellent biocompatibility
Agarwal et al
Successful proliferation of PC12 cells for reduced GO
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Concluding remarks
-The graphene based biosensors have exhibited good sensitivity and selectivity towards the detection of glucose, cholesterol, Hb, H2O2, small biomolecules, DNA, heavy metal ions and, poisonous gaseous molecules.

-Not only is graphene superior to carbon nanotubes in most types of electrochemical
sensing, but it also may prove to be a less expensive option making it an attractive alternative for large-scale manufacturing.

-Studies have yielded positive reports of graphene's ability to support cell proliferation

-From a fundamental perspective, some of graphene's intrinsic characteristics as well as biosensing capabilities merit much further study
18

Thanks for your attention
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