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By: Nidhi Vyas M.Sc. (pre) B.T.

Agenda • • • • • • •

Introduction Components Working Types Applications Future of biosensor Market of biosensor

Introduction /Definition • A biosensor is a device for the detection of an analyte that combines a biological component with a physicochemical detector component. OR • A biosensor is an analytical devices which employs a biological material to specifically interact with an analyte.

Biosensor consist by :-

Biosensor consists of 3 parts:• Sensitive biological element & analyte. • Transducer or the detector element. • Electronic or signal processor / Amplifier.

Components of biosensor:1.Analyte. 2.Biological material. 3.Transducer. 4.Amplifier. 5.LED screen/ PC.

Sensitive biological element:• Biological material a biologically derived material or can be created by biological engineering. • Biological material is like tissue, cell receptor, enzymes, antibodies, nucleic acid etc. • The biological component of biosensor performs the following two key function 1.It specifically recognizes the analyte . 2.Interacts with it in such a manner , which produces some physical change detectable by the transducer.

Transducer or the detector element:• The biological component interacts specifically to the analyte, which produced a physical change close to the transducer surface. • Transducer detects & measures this change and converts it into an electrical signal. • Transducer work in a physicochemical way, optical way, piezoelectric way, electrochemical way etc.

Analyte:• An analyte is a compound whose concentration is to be determined by the biosensor. • The nature of interaction between the analyte and the biological material used, the biosensor may be of two types – 1.The analyte may be converted into a new chemical molecule , such biosensor are called CATALYTIC BIOSENSOR. 2.The analyte may simply bind to the biological material, these biosensor are known as AFFINITY BIOSENSOR.

Immobilization of Biological element:• A biosensor makes use of a biological molecule (an enzyme ) that is immobilized to detect an analyte. • The immobilization permits repeated use of the costly biological molecule.

1)Diffusion of analyte 2)Reaction with bio. Element 3)Change in physicochemical properties 4)Change in optical/ electronic properties 5)Measurement, amplified and display

Working principle of biosensor:• The biosensor convert a chemical information flow, into an electrical information flow, which involves the following steps 1.The analyte diffuses from the solution to the surface of the biosensor. 2.The analyte react specifically & efficiently with the biological component of the biosensor. 3.This reaction change the physicochemical properties of the transducer surface. 4.This leads to a change in the optical/electronic properties of the transducer surface. 5.The change in optical/electronic properties is measured/ converted into electrical signal, which is amplified, processed and displayed.

Features of biosensor:A successful biosensor must have at least some of the following features – • Highly specific for analyte. • Independent of factors like stirring, pH, temp., etc. • Linear response, tiny and biocompatible. • Cheap, easy to use & durable/repeated use. • Cost is lower than that of conventional tests. • Require small sample volume. • Rapid, accurate, stable, & sterilizable.

Types of biosensor:• The biosensor are of the following five types – 1 Calorimetric. 2 Potentiometric. 3 Amperometric. 4 Optical. 5 Acoustic wave biosensor/Piezoelectric.

Types of biosensor, and the biological materials used in their construction:S.N.

Type of biosensor Type of change detected

Biological component

Example/ Remarks


Calorimetric/ thermometric



Can detect temp. difference of 0.0001 C



Consumption of a gas


Urea detection



Redox reaction


Glucose biosensor



Electrical conductivity


Urea detection



Fluorescence/ absorbance

Enzyme, Ab, DNA/RNA

Luciferase for bacteria detection



Resonant frequency


Cocaine detection


Whole cell

Based on 1, 2, 3 biosensor

Live/ dead Nicotinic acid microbial cells detection using Lact. arabinosus

Applications of Biosensor:• Biosensor can be used for many analytical problems, ranging from detection of industrial toxins and food contamination to monitoring the density of microbes in an industry and medical diagnostics. • Biosensor for medical diagnostics. • Biosensor for agriculture and food industry. • Biosensor for environment monitoring. • Toxicology tests using biosensor. • Biosensor for general industry. • Biosensor for military and defense industry.

Biosensor for medical diagnostics:• The most important application of biosensor is in the field of medical diagnostics. 1 Centralized tests in hospitals. 2 Tests in doctors clinics (form of portable biosensor ). 3 Tests by consumers ( by individuals ).

SPR Biosensor and it’s use :-


Glucose meter- for The DNA capture element measurement of glucose in instrument- for hereditary blood. diseases.

Biosensor for agriculture and food industry:• Various possible applications of biosensor in food industry and agriculture. 1 Detection of viral, fungal, bacterial diseases of plants. 2 In food industry, detection of total microbes and sugar quantification in soft drink. 3 Biosensor is also used to determine the freshness of fish, beef and other food items. Make bacteria glow by Optical biosensor.

Biosensor for environment monitoring:• Biosensor can also be used for monitoring the pollution level in the environment including air, land and water. • Biosensor can also be developed for monitoring the quality of water through tests for pollutants, chemical residues, pesticides, herbicides, toxins and microbes in water reservoirs.

Biosensor for Detection of pollution and chemicals of present in environment:-

Biosensor for general industry:(including fermentation industry) • Biosensor can also be used as analyzers for specific chemicals for process control in a variety of industries including pharmaceuticals, chemical petroleum, mining and construction industries. • In fermentation industry, biosensor can be used for monitoring the cultured microorganisms producing drugs, hormones, vaccines, single cell proteins etc. • Biosensor can also be developed for alerting workers for the presence of hazardous substances in the industrial atmosphere.

Biosensor for military and defense industry:• In military and defense organization, portable biosensor can be very useful for detection of toxic gases • And also in the agents of chemical warfare, such as mustard and nerve gas.

Commercial market of Biosensor:• Development of biosensor for commercial use is still in its infancy &has been rather slow, although research in this area predicts their use for solving many problems. • A medical diagnostics has a worldwide market of US $ 9 billion per annum.


bio sensors