A presentation on biosensors and its application,all datas r mainly collected from google search,and from some books by or teachers. Hope it will help you...leave your rply,, :)

1. By
JOY KARMAKAR
DEPARTMENT OF
INSTRUMENTATION SCIENCE
JADAVPUR UNIVERSITY

2.  A sensor is an object whose purpose is to
detect events or changes in its environment,
and then provide a corresponding output.
 e.g Pressure sensor, Ultrasonic sensor , Humidity Sensor , Gas
Sensor , Motion Sensor ,Biosensor , Acceleration sensor ,
Displacement sensor etc.
 A transducer is a device that converts one
form of energy to another.
 e.g pressure sensor might detect pressure (a mechanical form of
energy) and convert it to electrical signal for display at a remote
gauge.
 A sensor is a type of transducer.

3.  Accuracy (how much accurate reading it produces)
 Precision (how close is the measured value to the true
value)
 Resolution ( smallest incremental change in the input
that will produce a detectable change in the output)
 Sensitivity (ratio of incremental output to incremental
input)
 Selectivity and specificity (depends on the unwanted
signals)
 Non linearity (deviation from linearity, i.e deviation
from best fit straight line obtained by regression
analysis)
 Hysteresis

4.  A biosensor is an analytical
device, used for the detection of
an analyte, that combines a
biological component with
a physicochemical detector.

5.  Professor Leland C Clark Jnr is
known as the father of the
biosensor . On 15 April 1956 the
biosensor that he invented was
named after him as “Clark
electrode”(measured oxygen level
in blood).
 1975 Clark’s ideas became
commercial reality with the
successful re-launch of the
Yellow Springs Instrument
Company (Ohio) glucose analyser
based on the amperometric
detection of H2O2
 1977 Karl Cammann introduced
the term “biosensor” (1918-2005)

9. SENSING ELEMENTS
Enzymes
Enzymes are proteins with high catalytic activity and selectivity towards
substrates . They have been used for decades to assay the concentration of
diverse analytes. Their commercial availability at high purity levels makes
them very attractive for mass production of enzyme sensors. Enzymes have
been immobilized at the surface of the transducer by adsorption, covalent
attachment, entrapment in a gel or an electrochemically generated polymer,
in bilipid membranes or in solution behind a selective membrane. Enzymes
are commonly coupled to electrochemical and fiber optic transducers.

10. Antibodies
Antibodies are proteins that show outstanding selectivity. Molecules
larger than about 10kDa can stimulate an immune response.
Many antibodies are commercially available and commonly used in
immunoassays. Antibodies are usually immobilized on the surface of
the transducer by covalent attachment by conjugation of amino,
carboxyl, aldehyde, or sulfhydryl groups. The surface of the transducer
must be previously functionalized with an amino, carboxyl, hydroxyl, or
other group.

11. Microbes
The use of micro-organisms as biological elements in biosensors is
based on the measurement of their metabolism. Microbial cells have the
advantage of being cheaper than enzymes or antibodies,
can be more stable, and can carry out several complex reactions
involving enzymes and cofactors. Conversely, they are less selective
than enzymes, they have longer response and recovery times, and may
require more frequent calibration.

12. TRANSDUCING ELEMENTS
Principle of detection

13. PIEZOELECTRIC
 Materials
Quartz , Tourmaline,
Rochelle salt ,
Lithium Sulphate ,
Barium Titanate
 Shows
piezoelectric
effects i.e electric
polarisation
produced by
mechanical strain
in the crystal.
A piezoelectric disk
generates a voltage when
deformed (change in shape
is greatly exaggerated)

14. AMPLIFIER
An amplifier, is an
electronic device that
increases the power of
a signal
 Power amplifier
 Transistors
amplifier
 Operational
amplifier etc
OP-AMP

15. A/D CONVERTER
 Counter
controlled A/D
converter
 Successive
approximation
A/D converter
 Flash/parallel
A/D converter
 Dual slope A/D
converter
:
4DIGIT 7 SEGMENT DISPLAY

16. APPLICATIONS
 Glucose monitoring , pregnancy test in diabetes patients ←historical market
driver
 Environmental applications e.g. the detection of pesticides and river water
contaminants such as heavy metal ions
 Remote sensing of airborne bacteria e.g. in counter-bioterrorist activities
 Remote sensing of water quality in coastal waters by describing online
different aspects of clam ethology (biological rhythms, growth rates,
spawning or death records) in groups of abandoned bivalves around the
world
 Determining levels of toxic substances before and after bioremediation
 Routine analytical measurement of folic acid, biotin, vitamin B12 and
pantothenic acid as an alternative to microbiological assay
 Drug discovery and evaluation of biological activity of new compounds
 Detection of toxic metabolites such as mycotoxins

17. GLUCOSE MONITORING IN BLOOD

18. IN AGRICULTURE,FOOD INDUSTRY
 DETECTION OF VIRAL FUNGAL BACTERIAL DISEASE
OF PLANTS
 DETECTION OF FOOD, TOTAL MICROBES IN SOFT
DRINKS
 DETERMINE FRESHNESS OF FRUIT,MEAT,FISH ETC.
OPTICAL BIOSENSOR USES CYANIDE TO
GLOW BACTERIA AND DETECT IT

19. Tattoo biosensor warns when athletes
are about to ‘hit the wall’

20. Disadvantages
 1. Heat sterilization is not possible because of
denaturaization of biological material,
 2. Stability of biological material (such as enzyme, cell,
antibody, tissue, etc.), depends on the natural properties
of the molecule that can be denaturalized under
environmental conditions (pH, temperature or ions)
 3. The cells in the biosensor can become intoxicated by
other molecules that are capable of diffusing through the
membrane
 4.Fabrication is Costly

21. CONCLUSION
We can say that developing a biosensor is related with
interdisciplinary study as Biology, Biochemistry, Chemistry,
Electrochemistry, Physics, Kinetics and Mass transfer
knowledge is required for this study.
Proportional to the technological development and increase of
interdisciplinary studies biosensors are being more useful and
having more usage areas day by day.
Recent development topics which are
Electrochemical biosensor ,Fiber-optic biosensor
Carbon Nanotube , Protein Engineering for biosensors
Wireless Biosensors Networks
So in near future the fabrication and use of Biosensors is going
to be revolutionary.

22. BIBLIOGRAPHY
• www.wikipedia.org
• http://cdn.intechopen.com/pdfs/37345/InTech-
Biosensors_and_their_principles.pdf
• Sensors and Transducers book by D Patranabis
• http://biosensor.se/
• http://www.biosensors-congress.elsevier.com/
• Fundamental prinples of Electronics by Dr B. Ghosh