A Descriptive Review over the field of Biosensors has been given here; its origin history events; its working principle; its classification based on various parameters; applications and future scope

1. Presentation On
Term Paper (1st Semester)
Amity School of Engineering and Technology
Amity University Uttar Pradesh
Lucknow
BIOSENSORS : A REVIEW
Adrija Chowdhury
M.Tech (OEOC)

2. INTRODUCTION
Biological and biochemical processes have a very important role on
medicine, biology and biotechnology.
It is very difficult to convert directly biological data to electrical
signal.
Biosensors can convert these signals over come this difficulty.
Sensors are being developed to address the need for real time
analytical measurements in the field.

3. History of biosensors
1962 – Leland C. Clark first described a biosensor as an
enzyme electrode for glucose [4]
1969 – First potentiometric biosensor
1970s–Ion Selective Field Effect Transistor, Fiber Optic
Sensor
1980s–First Surface Plasmon Resonance Immunosensor
(SPR)
1990s – SPR based and handheld biosensors
Current –nanobiosensors

4. BIOSENSORS
An analytical device which is used to determine the presence and
concentration of a specific substance in a biological analyte.
Other names immuno-sensors, optrodes, chemical canaries, resonant mirrors,
gluco-meters, biochips, bio-computers.
IUPAC: “A biosensor is a self-contained integrated device which is capable of
providing specific quantitative or semi-quantitative analytical information using
a biological recognition element (biochemical receptor) which is in direct spatial
contact with a transducer element” [1,2,5]
BIORECEPTOR + TRANSDUCER = BIOSENSOR
Biosensor ≠≠ Bio-analytical System

5. WORKING: BIOSENSOR SYSTEMS
Biological materials used: enzymes/substrate, antibody/ antigen and nucleic
acids/complementary sequences, microorganisms, animal or plant whole cells and
tissue slices.
sensing elements: electrochemical, optical, thermometric, piezoelectric.[3, 5]
Principle of detection: specific binding of the analyte of interest to the
complementary bio-recognition element.
Specific interaction results in a change in one or more physico-chemical
properties (pH change, electron transfer, mass change, heat transfer, uptake or
release of gases or specific ions).

6. Components of a Biosensor
Detector

7. IMMOBILIZATION TECHNIQUES ADOPTED
Physical Adsorption
Microencapsulation
Entrapment
Covalent Attachment/ Bonding
Cross-linking

8. CLASSIFICATION OF BIOSENSORS

9. BASED ON BIORECOGNIZATION ELEMENTS
Biologics such as enzymes, antibodies, DNA, receptors and even
biological cells and microorganisms that selectively recognize an
analyte.
Categorized as:-
(i) Catalytic biosensors
(ii) Affinity biosensors

10. BASED ON TRANSDUCTION ELEMENTS
RESONANT BIOSENSORS: Measures change in mass
ELECTROCHEMICAL BIOSENSORS: Measures change in electric
distribution. Further classified into Amperometric, Conductimetric and
Potentiometric ones.
OPTICAL DETECTION BIOSENSORS: Measures change in light
intensity
THERMAL DETECTION BASED BIOSENSORS: Measures change in heat
ION SENSITIVE BIOSENSORS

11. Sensing techniques BEING USED

12. CHARACTERISTICS OF BIOSENSORS
LINEARITY: Linearity of the sensor should be high for the detection of high
substrate concentration.
SENSITIVITY: Value of the electrode response per substrate concentration.
SELECTIVITY: Chemicals Interference must be minimized for obtaining the
correct result.
RESPONSE TIME: Time necessary for having 95% of the response.
ACCURACY: Around ±5%
RECOVERY TIME: Time before biosensor is ready to analyse the next sample;
should not be more than a few minutes.
WORKING LIFETIME: Determined by instability of the biological material;
vary from a few days to few months; Exactech glucose biosensor is usable for over
1 year.

13. APPLICATIONS OF BIOSENSORS
Healthcare (glucose, artificial pancreas)
Process control: fermentation control and analysis
Food and drink production and analysis
Pollution control and monitoring
Mining, industrial and toxic gases
Military applications
Pharmaceutical and drug analysis

14. CONCLUSION
With increasing threat of bioterrorism, the development of faster, reliable,
accurate, portable and low-cost biosensors has become much more
important than ever as they could play an important role in providing
powerful analytical tools to the agricultural diagnosis sector,
environmental safety, bioterrorism, biomedical research and drug
discovery where rapid, low cost, high sensitivity and specificity
measurements in field situations are required. The combination of
nanotechnology, molecular biology and photonics opens the possibility of
developing nano-devices [5] which have the potential for a wide variety
of diagnostic and therapeutic uses at the molecular and cellular level.
Optical nanosensors for living cell analysis are promising analytical tools
that needs to mature

15. REFERENCES
[1] R. S. Marks et. al., “Handbook of Biosensors and Biochips”, John Wiley
& Sons, Ltd., 1st
edition, 2007.
[2] P. N. Prasad, “Introduction to Biophotonics”, John Wiley & Sons, Inc.,
Publication, 1st
edition, 2003.
[3] Arnold, M.A Meyerhoff, M.E. Recent Advances in the Development and
Analytical
Applications of Biosensing Probes. Crit. Rev. Anal. Chem., 20, 149–196,
1988.
[4] Clark, L.C.; Lyons, C. Electrode systems for continuous monitoring
cardiovascular surgery.
Ann. N. Y. Acad. Sci., 102, 29–45, 1962
[5] C. Aston, “Biological warfare canaries,” IEEE Spectr., vol. 38, no. 10, pp.
35–40, Oct. 2001.

16. THANK YOU
Any queries ???