CONTENTS
 Introduction
 What is biosensor?
 History
 Types
 Commercial Application
 Conclusion
 Biosensor is an analytical device, which converts a
biological response into electrical signal.
The term biosensor is often used to cover sensor devices
used in order to determine the conc. of substances and
other parameters of biological interest even where they
do not utilize a biological system directly
Biosensors are method of rapid, infield detection of
disease toxins such as pesticides and hazardous wastes.
They are becoming an increasingly popular analytical
tool
among
environment.
analytical
chemist
involved
with
Current Definition for
Biosensors:
A sensor that integrates a biological element with a physiochemical
transducer to produce an electronic signal proportional to a single analyte
which is then conveyed to a detector.
www.imec.be/ovinter/static_research/BioHome.shtml
HISTORY
 The father of biosensor is Prof. L.D. Clark.
 He made a landmark address in 1962 at a New
York Academy of Sciences Symposium in which
he described how to make electro chemical
sensor. He named it enzyme electrode.
• Guilbault
&
potentiometric
Montalvo
first
time
enzyme electrode.
gave
• In 1975 first time Glucose analyzer was
commercially available.
• In 1987 Medisense company introduced a pen
sized meter for home blood glucose monitoring.
Biosensor consist of THREE
part
1ST Component: Biological
Element
The component used to bind the target molecule.
Must be highly specific, stable under storage conditions, and immobilized.
Microorganism
Tissue
Cell
Organelle
Nucleic Acid
Enzyme
Enzyme Component
Receptor
Antibody
http://www.chemistry.wustl.edu/~edudev/LabTutorials/HIV/DrugStrategies.html
2ND Component: Physiochemical
Transducer
Acts as an interface, measuring the physical change that occurs with the reaction at
the bioreceptor then transforming that energy into measurable electrical output.
3RD Component: Detector
Signals from the transducer are passed to a
microprocessor where they are amplified and
analyzed.
The data is then converted to concentration units
and transferred to a display or/and data storage
device.
www.modernmike.com
Analyte
Biological
component
Signal
transducer
Recorder
What do they have in common?
Biosensor
Analyte / bioreceptor / transducer / processor
Nose
Small molecules / olfactory membrane / nerve cells / brain
Eye
Visible light / rods and cones / nerve cells / brain
TYPES OF BIOSENSOR ON THE BASIS OF
TRANSDUCER ELEMENT
1.OPTICAL
2.PIEZOELECTRIC
3.ELECTROCHEMICAL
4.THERMAL
OPTICAL
1.SURFACE PLASMON
 QUANTISATION OF ELECTRON
RESONANCE
PLASMA IS PLASMON
 EXCITATION OF SURFACE PLASMON
BY ELECTRONS OR PHOTONS
 CHANGE IN THE REFRACTIVE INDEX
OF SURFACE DUE TO ADDITION OF
FOREIGN PARTICLES
 MEASUREMENT OF THE ANGLE OF
MINIMUM REFLECTANCE AND
CHANGE IN THE SAME
SPR implementation
Incident Light
Reflected Light
I
Flow Cell
Molecules in solution exhibit changes in
refractive index and give rise to a
measurable SPR signal when binding occurs.
SPR implementation
Incident Light
Reflected Light
II
Flow Cell
Molecules in solution exhibit changes in
refractive index and give rise to a
measurable SPR signal when binding occurs.
2.Integrated optical
interferometric sensor
Reference
Sample
Integrated optical interferometric sensor
Reference
Sample
Pathogenic
Bacteria
Integrated optical interferometric sensor
Reference
Phase shift
of light
Sample
Binding to
Substrate
Interferometer
+
Constructive addition: Two light waves
with the same phase sum to give a
greater amplitude
Interferometer
+
Cancellation: Two light waves
that are 180o out of phase sum to
give zero amplitude
PIEZOELECTRIC
MECHANISM
 ORIGINAL POLARISATION IN THE
CRYSTAL + MECHANICAL STRESS
 CHANGE IN POLARISATION (REORIENTATION OF WIESS
DOMAIN,ETC.)
 PRODUCTION OF VOLTAGE DUE TO
CHANGE IN SURFACE CHARGE
DENSITY
Naturally-occurring crystals
•Berlinite (AlPO ), a rare phosphate
mineral that is structurally identical to
quartz
•Cane sugar
•Quartz
•Rochelle salt
•Topaz
•Tourmaline-group mineralsedit
•Other natural materials
•Tendon
•Silk
•Wood due to piezoelectric texture
•Enamel
•Dentin
4
 Man-made crystals
 Gallium orthophosphate (GaPO4), a quartz analogic crystal
 Langasite (La3Ga5SiO14 ), a quartz analogic crystal
 Man-made ceramics
 Barium titanate (BaTiO3)—

Lead titanate (PbTiO3 )
 Potassium niobate (KNbO3)
 Lithium niobate (LiNbO3)
 Lithium tantalate (LiTaO3)
 Sodium tungstate (Na2WO3)
 Ba2NaNb5O5
 Pb2KNb5O15
If the enzyme catalyzed reaction is exothermic, two thermistors may be
used to measure the difference in resistance between reactant and product
and, hence, the analyte concentration.
www4.tsl.uu.se/~Atlas/DCS/DCSIL/therm.html
ELECTROCHEMICAL BIOSENSORS
 Potentiometric for voltage: Change in
distribution of charge is detected using ion-selective
electrodes, such as pH-meters.
•Amperometric for applied current: Movement
of e- in redox
reactions detected when a potential is applied
between two electrodes.
http://www.lsbu.ac.uk/biology/enztech/index.html
ON THE BASIS OF BIOLOGICAL ORGANISMS
BIOSENSOR ARE CLASSIFIED.
 Bacterial biosensors.
 Antibodies (Immunosensors)
 Tissue
 Enzymes
BACTERIAL BIOSENSORS
Majority of luminous
bacteria are found in nature
in marine environments and in
association in symbiosis with
host organisms
Bacterial luciferase is the
enzyme that catalyses light
emission at the heart of
bacterial luminescence.
The catalytic machinery
includes
enzymes
that
supply and regenerate the
substrates
of
bacterial
luciferase.
The DNA sequences coding
the
proteins
in
the
luminescent
system
are
called the lux genes.
WORKES ON THE PRINCIPLE OF BIOLUMINISENCE
Bacterial luciferase is the
enzyme that catalyses light
emission at the heart of
bacterial luminescence.
The catalytic machinery
includes enzymes that supply
and regenerate the
substrates of bacterial
luciferase.
The DNA sequences coding
the proteins in the
luminescent system are
called the lux genes.
Trial materials, January 2006
Biosensors
TOXIN
luciferase
-CHO
reductase
Trial materials, January 2006
COOH
Biosensors
Photobacterium phosphoreum
is a type of bacterium which
displays luminescence i.e. it
gives out visible light (shines)
o Toxins (or poisons) reduce
Photobacterium’s ability
to respire
How brightly it shines
depends on how well the
bacterium can respire
o Therefore it
cannot shine so
brightly
o You can use
Photobacterium to
detect (sense) toxins
Trial materials, January 2006
Biosensors
IMMUNOSENSOR
There are several applications of
biosensors in food analysis. In food
industry optic coated with antibodies are
commonly used to detect pathogens and
food toxins. The light system in these
biosensors has been fluorescence, since
this type of optical measurement can
greatly amplify the signal.
A range of immuno- and ligand-binding
assays for the detection and
measurement of small molecules such as
water-soluble vitamins and chemical
contaminants (drug residues) such as
sulfonamides and Beta-agonists have
been developed for use on SPR based
sensor systems, often adapted from
existing ELISA or other immunological
 .
BIOSENSORS IN DETECTING
METALLIC ION (by Tuan VoDinh)
BIOSENSORS AS
MICROCALORIMETER
 CONCEPT OF MICROCANTILEVER
 MEASURING SMALL VOLUME
REACTION TEMPERATURE
BIOSENSORS AS MEDICAL
TELESENSORS
 BODY TEMPERATURE (by Tom
Ferrell)
 BLOOD PRESSURE (piezoelectric)
 OXYGEN LEVEL(optical)
 PULSE RATE(Piezoelectric)
BIOSENSORS IN CANCER
DETECTION
 Here's how it works. Laser light of the
appropriate wavelength is directed to the
inner surface of the esophagus by means
of a fiber-optic device that is swallowed by
the patient. The epithelial cells and tissue
inside the esophagus fluoresce when exc
ited by the laser light. When the
esophagus interior is illuminated with blue
light [410 nanometers (nm)], the normal
tissue emits light at wavelengths different
from those emitted by the cancer cells
Laser fluorescence diagnosis
is accurate in over 98% of
the cases
SOME MORE CANCER
DETECTION METHODS
BIOSENSORS IN REMOTE
SENSING OF BACTERIA
 Air borne bacteria can be detected
by
illuminating with laser light.
 Nanotechnology
is
helpful
in
conforming the test for bird flu.
• The
application
of
nanotechnology
to
biosensor design and fabrication promises to
revolutionize diagnostics and therapy at the
molecular and cellular level.
• The nanoprobes and nanosensors have the
potential for a wide variety of medical uses at
the cellular level with in the living cell.
• NASA
has
developed
a
revolutionary
nanotechnology-based biosensor that can
detect trace amounts of specific bacteria
viruses and parasites. That will used to help
prevent the spread of potentially deadly
biohazards in water, food and other
contaminated sources.
 Ultra sensitive carbon nanotubes are
used which can detect biohazards at
very low levels.
 Enzyme gold colloids have been used for
H2O2, Glucose, Xanthine, detection.
 Carbon
nanotubes
based
electro
chemiluminesence biosensors have used
for immobilization of biomolecules.
Potential Applications
•
•
•
•
Clinical diagnostics
Food and agricultural processes
Environmental (air, soil, and water) monitoring
Detection of warfare agents.
www.fuji-keizai.com/e/report/biosensor2004_e.html
APPLICATIONS IN A REVIEW
 There are many potential applications of
biosensors of various types. The main
requirements for a biosensor approach to
be valuable in terms of research and
commercial application. Some examples
are:
 Glucose monitoring in diabetes patients.
 Other medical health related targets.
 Warfare
 Environmental applications
Remote sensing of air borne bacteria
Determination of toxic substances before and after
bioremediation.
Detection of toxic metabolite such as mycotoxins.
There are several applications of biosensors in food
analysis. In food industry optic coated with antibodies
are commonly used to detect pathogens and food
toxins. The light system in these biosensors has been
flourosense, since this type of optical measurement
can greatly amplify the signal.
FUTURE OF BIOSENSORS:• A Soldier Could be wearing a wrist watch
device, with a network of small receptors if he
encounter with a particular pathogen anthrax or
small pox, receptors would bind to the pathogen
much like antibodies.
•In the mask, biosensors will be put against
harmful chemicals.
•Biosensors should be made smaller more
portable and can detect various agent for fall
protection.
•Wounded soldiers should be treated by
biomaterials- so that it can be compatible
with human body.
•Uniforms of the soldiers might be fitted
with protective armor as hard and light
weight can change the colour with
environment just like chameleon.
•Tanks and aircraft could be covered with
paint derived from a bacterial protein
capable of absorbing radiation, thus
enabling them to elude radar detection by
an enemy.
INNOVATIONS MARK BIOSENSOR
DEVELOPMENT
•A number of companies are exploring new designs,
improvements and upgrades for their biosensor
technologies.
•Biacore, now part of GE Health Care is upgrading it
product over the years a new hardware and software
make it much more accessible as a means of studying
molecular interactions. Peer reviewed studies using
the Bia core T 100 and Bia core A 100 systems.
Genetic and Biogen Idec and large no. of
academic institutions are having screening of
hybridomas for mAB selection and
immunogenicity studies
CURRENT SCENARIO
 A
number
of
companies
are
exploring
new
designs,
improvements and upgrade for their
biosensor technology are its ability
simple
and
quickly
measure
biological and chemical substances.
Conclusion
The possibilities are endless!
http://www.must.edu.my/~ccyeo/topics/biosensor.jpg
REFERENCES
1.
2.
3.
4.
5.
WWW.NANOWERK.COM/SPOTLIGHT
WWW.NCBI.NLM.NIH.GOY/PUBMED/15262314
WWW.WORLDFOODSCIENCE.ORG/CMS/PID
WWW.EMERSALDINSIGHT.COM
MAXWELL D., TAYLOR M.J., NIE S. SELF
ASSEMBLED NANOPARTICLE PROBES FOR
RECOGNITION AND DETECTION OF
BIOMOLECULES
6. WIKIPEDIA
7. SOLID STATE PHYSICS BY E. HALL, 2e