Carbon nanotubes have potential applications in biosensor development due to their electrical and physical properties. A biosensor consists of a biological recognition component and a transducer. Carbon nanotubes can act as both the immobilization platform for the biological recognition element and as an electronic mediator in the transducer. Their high conductivity and surface area make them suitable for creating bionanoelectroanalytical devices with applications in food analysis, medical diagnosis, environmental monitoring and other fields.

1. APPLICATION OF CARBON
NANOTUBE IN
BIOSENSOR

2.  A sensor is an instrument that responds to a physical stimulus (such as
heat, light, sound, pressure, magnetism, or motion)
 It collects and measures data regarding some property of a phenomenon,
object, or material.
 Sensors are an important part to any measurement and automation
application.
 The sensor is responsible for converting some type of physical
phenomenon into a quantity measurable by a data acquisition (DAQ)
system.
Sensor

3. 3
Biosensor ???
Analyte
Biomolecule Transducer SIGNAL

5. Components of a Biosensor

6. Biosensors Timeline
1916 First report on immobilization of proteins : adsorption of
invertase on activated charcoal
1922 First glass pH electrode
1956 Clark published his definitive paper on the oxygen
electrode.
1962 First description of a biosensor: an amperometric enzyme
electrode for glucose (Clark)
1969 Guilbault and Montalvo – First potentiometric biosensor:
urease immobilized on an ammonia electrode to detect urea
1970 Bergveld – ion selective Field Effect Transistor (ISFET)

7. Biosensors Timeline
1975 Lubbers and Opitz described a fiber-optic sensor with
immobilized indicator to measure carbon dioxide or
oxygen.
1975 First commercial biosensor ( Yellow springs Instruments
glucose biosensor)
1975 First microbe based biosensor, First immunosensor
1980 First fiber optic pH sensor for in vivo blood gases
(Peterson)
1982 First fiber optic-based biosensor for glucose
1983 First surface Plasmon resonance (SPR)
immunosensor
1984 First mediated amperometric biosensor: ferrocene used
with glucose oxidase for glucose detection
1987 Blood-glucose biosensor launched by MediSense

8. Biosensors Timeline
1990 SPR based biosensor by Pharmacia BIACore
1992 Hand held blood biosensor by i-STAT
1996 Launching of Glucocard
1998 Blood glucose biosensor launch by LifeScan FastTake
1998 Roche Diagnostics by Merger of Roche and Boehringer
mannheim
Current Quantum dots, nanoparticles, nanowire, nanotube, etc.

9. BIOSENSOR
Analyte
Sample
handling/
preparation
Detection
Signal
Analysis
Response

10. BIOSENSOR
 The Analyte (What do you want to detect)
Molecule - Protein, toxin, peptide, vitamin, sugar, metal ion
 Sample handling (How to deliver the analyte to the sensitive
region?)
(Micro) fluidics-Concentration
increase/decrease),Filtration/selection
 Detection/Recognition
((How do you specifically recognize the analyte?)
 SignalSignal
((How do you know there was a detection?)

11. Example of biosensors
Pregnancy test
Detects the hCG protein in urine.
Glucose monitoring device (for diabetes patients)
Monitors the glucose level in the blood.

12. Example of biosensorsExample of biosensors
Infectous disease
biosensor from RBS
Old time coal miners’ biosensor

13.  Nano sensors deliver real-time information about the antibodies to
antigens, cell receptors to their glands, and DNA and RNA to nucleic
acid with a complimentary sequence.
 Sensitivity of the conventional biosensors is in the range between 103
and 104
colony forming units (CFU)/ml.
 The dimensional compatibility of nanostructured materials renders
nanotechnology as an obvious choice derived from its ability to detect
~ 1 CFU/ml sensitivity.
 Reduced detection time than conventional methods.
Size and Compatibility

14. Scheme 1. Representation of recognition process and application of Biosensor
Applications
Environmental
Food
Medical diagnosis
Recognition principle Transducing mechanism
Luminescence
Absorption
Polarization
Fluorescence
Conductometric
Amperometric
Potentiometric
Ion-sensitive
Acoustic wave
Microbalance
Resonant
Antibodies
Enzyme
Organelle
Vitamins
pH
Immunological
analytes
Cell or tissue
Volatile gases &
vapors ions
Biosensors
DNA
Antibody/antigen
Molecular recognition
Enzymatic
Optical
Mass
Electrochemical
Piezoelectric
Thermal

15. • Carbon Nanotubes… a brief introduction
• Types of CNTs
• Applications of CNTs
•Summary
Carbon Nanotube

16. What arecarbon nanotubes?
Carbon nanotubes are carbon cylinders made up of one or more
rolled up graphene sheets, closed off at either end by half
spheres in the shape of a soccer ball.

17. Salient features of CNTs
• 100 times stronger than Steel and 1/6th
the weight of steel.
(Tensile strength value, 63 GPa, exceeds that of any reported
valuefor any typeof material.
•Applications for very light-weight, high-strength cables and
composites, where the carbon nanotubes are the load-carrying
element.)
• Electrical conductivity as high as copper, thermal conductivity
ashigh asdiamond.
• Average diameter of 1.2 – 1.4 nm (10000 times smaller than a
human hair).

18. On thebasisof their physical properties two different form of
CNTscan bedistinguished :
Types of Carbon nanotubes

19. Single wall carbon nanotubes

20. Multiwall carbon nanotubes
 MWCNTs consist of multiple rolled-up graphene sheets in
two different structures called
 Russian doll model: where graphene sheet are rolled up in
concentric cylinders .
 Parchment model : where one graphene sheet is rolled like a
scroll of parchment .

21. Applicationsof Carbon Nanotubes
Nanotubes can be opened and filled with
materials such as biological molecules,
raising the possibility of applications in
biotechnology.

22. Summary
 Carbon nanotubesarerolled up graphenesheets.
 Biosensorsarebio analytical devicesconsisting of abio receptor
and atransducer.
 CNT playsdual rolein abiosensor both asimmobilization matrices
and aselectron mediator.
 Thehigh conductivity and high surface-areaof CNTsmakethem a
better material for bionanoelectroanalytical devices.

23. Application of Biosensors
 Food Analysis
 Study of biomolecules and their interaction
 Drug Development
 Crime detection
 Medical diagnosis (both clinical and laboratory use)(both clinical and laboratory use)
 Environmental field monitoring
 Quality control
 Industrial Process Control
 Detection systems for biological warfare agents
 Manufacturing of pharmaceuticals and replacement
organs

24. References
1. Eugenii Katz and Itamar Willner ,“Biomolecule-Functionalized
Carbon Nanotubes: Applications in Nanobioelectronics”
ChemPhysChem 2004, 5, 1084 -1104.
2. Pejcic B, De Marco R, Parkinson G., “The role of biosensors in
the detection of emerging infectious diseases", Royal society of
chemistry,2006,131,1079-1090.