Biosensors (BT 440)

Course Instructor
Dr. Ashish A Prabhu
Assistant Professor
Department of Biotechnology
1 NIT Warangal
 Syllabus
 Unit 1:General principles: A historical perspective; Signal transduction; Physico-chemical and
biological transducers; Sensor types and technologies, Definitions and Concepts Terminology
and working vocabulary; Main technical definitions: calibration, selectivity, sensitivity,
reproducibility, detection limits, response time.
 Unit 2:Physico-chemical transducers: Electrochemical transducers (amperometric,
potentiometric, conductimetric); optical transducers (absorption, fluorescence, SPR); Thermal
transducers; piezoelectric transducers.
 Unit 3:Biorecognition systems: Enzymes; Oligonucleotides and Nucleic Acids; Lipids
(LangmuirBlodgett bilayers, Phospholipids, Liposomes); Membrane receptors and
transporters; Tissue and organelles (animal and plant tissue); Cell culture; Immunoreceptors;
Chemoreceptors; Limitations & problems. Immobilization of biomolecules.
 Unit 4:Biosensor Engineering: Methods for biosensors fabrication: self-assembled monolayers,
screen printing, photolithography, micro-contact printing, MEMS.
 Unit 5:Engineering concepts for mass production. Application of modern sensor technologies:
Clinical chemistry; Test-strips for glucose monitoring; Urea determination.
 Unit 6: Implantable sensors for long-term monitoring; Environmental monitoring;
Technological process control; Food quality control; Forensic science benefits; Problems &
2 limitations.
Course Outcome
 Understand biosensing and transducing techniques.
 Understand principles of linking cell components and biological
pathways with energy transduction, sensing and detection.
 Demonstrate appreciation for the technical limits of performance
of biosensor
 Apply principles of engineering to develop bioanalytical devices
and design of biosensors

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Referred Readings
 Donald G. Buerk, Biosensors: Theory and Applications, CRC
Press, 2009
 Alice Cunningham, Introduction to Bioanalytical Sensors, John
Wiley& Sons, 1998.
 Brian R. Eggins, Chemical Sensors and Biosensors, John Wiley&
Sons, 2003
 Recent Publications highlighting the applications of biosensors

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What is biosensors?
 A biosensor is a device that measures
biological or chemical reactions by
generating signals proportional to the
concentration of an analyte in the reaction.
 The term ‘‘biosensor’’ was coined by
Cammann, and its definition was introduced
by IUPAC (International Union of Pure and
Applied Chemistry).
 Biosensors are employed in applications
such as disease monitoring, drug discovery,
and detection of pollutants, disease-causing
micro-organisms and markers that are
indicators of a disease in bodily fluids
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(blood, urine, saliva, sweat).
Nose as a sensor

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Basic terminologies in biosensors
 Analyte: A substance of interest that
needs detection.
 Bioreceptor: A molecule that specifically
Analytes
recognizes the analyte is known as a
bioreceptor.
 Bio-recognition: The process of signal
generation (in the form of light, heat, pH,
charge or mass change, etc.) upon
Bioreceptors
interaction of the bioreceptor with the
analyte.
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Basic terminologies in biosensors
 Transducer: The transducer is an element that
converts one form of energy into another. In a
biosensor the role of the transducer is to convert the
bio-recognition event into a measurable signal. This
process of energy conversion is known as Transducers
signalization.
 Electronics: This is the part of a biosensor that
processes the transduced signal and prepares it for
display. Signal Processor
 Display: The display consists of a user interpretation
system such as the liquid crystal display of a
computer or a direct printer that generates numbers
or curves understandable by the user.
8 Display
Basic Components in biosensors

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Schematic representation of Biosensor

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 Key Milestones

1956
Leland C. Clark,
Biosensors for oxygen
determination
Amperometric enzyme
1962
electrode for the detection of
glucose by Leland
Clark
Potentiometric biosensor to
1969 detect urea by Guilbault
and Montalvo
First commercial biosensor
was developed by Yellow 1975
Spring Instruments

1992 Handheld blood biosensor by i-STAT

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 Coupling of Bio and sensor
elements

Membrane entrapment Physical Adsoprtion

Matrix entrapment Covalent bonding

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 Parameters of the biosensors
 Selectivity: Selectivity is the ability of a bioreceptor to detect a specific
analyte in a sample containing other admixtures and contaminants.
 Reproducibility: Reproducibility is the ability of the biosensor to
generate identical responses for a duplicated experimental set-up.
 Stability : Susceptibility for the external disturbance
 Sensitivity : The minimum amount of analyte that can be detected by a
biosensor defines its limit of detection (LOD) or sensitivity.
 Linearity: Linearity is the attribute that shows the accuracy of the
measured response.
 Accuracy
 Nature of Solution
 Response time
 Recovery time
 Working life time
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Applications of Biosensors

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 Application of Biosensors (Contd)

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 Challenges in biosensors research
• Identification of the market that is interested in a biosensor for a specific
analyte of interest.
• Clear-cut advantages over existing methods for analyses of that analyte.
• Testing the performance of the biosensor both in use and after storage.
Response of a biosensor after 6 months of storage is the absolute
minimum for any practical commercial application.
• Stability, costs and ease of manufacturing each component of the
biosensor.
• Hazards and ethics associated with the use of the developed biosensor.

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 Market of Biosensors

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 Thank You

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