Term Paper (1st Semester)
Amity School of Engineering and Technology
Amity University Uttar Pradesh
BIOSENSORS : A REVIEW
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
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.
History of biosensors
1962 – Leland C. Clark first described a biosensor as an
enzyme electrode for glucose 
1969 – First potentiometric biosensor
1970s–Ion Selective Field Effect Transistor, Fiber Optic
1980s–First Surface Plasmon Resonance Immunosensor
1990s – SPR based and handheld 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
WORKING: BIOSENSOR SYSTEMS
Biological materials used: enzymes/substrate, antibody/ antigen and nucleic
acids/complementary sequences, microorganisms, animal or plant whole cells and
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).
BASED ON BIORECOGNIZATION ELEMENTS
Biologics such as enzymes, antibodies, DNA, receptors and even
biological cells and microorganisms that selectively recognize an
(i) Catalytic biosensors
(ii) Affinity biosensors
BASED ON TRANSDUCTION ELEMENTS
RESONANT BIOSENSORS: Measures change in mass
ELECTROCHEMICAL BIOSENSORS: Measures change in electric
distribution. Further classified into Amperometric, Conductimetric and
OPTICAL DETECTION BIOSENSORS: Measures change in light
THERMAL DETECTION BASED BIOSENSORS: Measures change in heat
ION SENSITIVE BIOSENSORS
CHARACTERISTICS OF BIOSENSORS
LINEARITY: Linearity of the sensor should be high for the detection of high
SENSITIVITY: Value of the electrode response per substrate concentration.
SELECTIVITY: Chemicals Interference must be minimized for obtaining the
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
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
Pharmaceutical and drug analysis
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  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
 R. S. Marks et. al., “Handbook of Biosensors and Biochips”, John Wiley
& Sons, Ltd., 1st
 P. N. Prasad, “Introduction to Biophotonics”, John Wiley & Sons, Inc.,
 Arnold, M.A Meyerhoff, M.E. Recent Advances in the Development and
Applications of Biosensing Probes. Crit. Rev. Anal. Chem., 20, 149–196,
 Clark, L.C.; Lyons, C. Electrode systems for continuous monitoring
Ann. N. Y. Acad. Sci., 102, 29–45, 1962
 C. Aston, “Biological warfare canaries,” IEEE Spectr., vol. 38, no. 10, pp.
35–40, Oct. 2001.