03-08-2012, 11:56 AM
BIOSENSOR
biosensors.ppt (Size: 188 KB / Downloads: 47)
INTRODUCTION
It is an analytical device which converts a biological response into an electrical signal.
It detects, records, and transmits information regarding a physiological change or process.
It determines the presence and concentration of a specific substance in any test solution.
BIO-ELEMENT
Function
To interact specifically with a target compound i.e. the compound to be detected.
It must be capable of detecting the presence of a target compound in the test solution.
The ability of a bio-element to interact specifically with target compound (specificity) is the basis for biosensor.
RESPONSE FROM BIO-ELEMENT
Heat absorbed (or liberated ) during the interaction.
Movement of electrons produced in a radox reaction.
Light absorbed (or liberated ) during the interaction.
Effect due to mass of reactants or products.
TYPES OF BIOSENSOR
Electrochemical biosensor
Optical biosensor
Thermal biosensor
Resonant biosensor
Ion-sensitive biosensor
ELECTROCHEMICAL BIOSENSOR
Principle
Many chemical reactions produce or consume ions or electrons which in turn cause some change in the electrical properties of the solution which can be sensed out and used as measuring parameter.
Classification
(1) Amperometric biosensor
(2) Conductimetric biosensor
(3) Potentiometric biosensor
GLUCOSE BIOSENSOR
Glucose reacts with glucose oxidase(GOD) to form gluconic acid. Two electrons & two protons are also produced.
Glucose mediator reacts with surrounding oxygen to form H2O2 and GOD.
Now this GOD can reacts with more glucose.
Higher the glucose content, higher the oxygen consumption.
Glucose content can be detected by Pt-electrode.
APPLICATIONS OF BIOSENSOR
In food industry, biosensors are used to monitor the freshness of food.
Drug discovery and evaluation of biological activity of new compounds.
Potentiometric biosensors are intended primarily for monitoring levels of carbon dioxide, ammonia, and other gases dissolved in blood and other liquids.
Environmental applications e.g. the detection of pesticides and river water contaminants.
Determination of drug residues in food, such as antibiotics and growth promoters.
Glucose monitoring in diabetes patients.
Analytical measurement of folic acid, biotin, vitamin B12 and pantothenic acid.
Enzyme-based biosensors are used for continuous monitoring of compounds such as methanol, acetonitrile, phenolics in process streams, effluents and groundwater.
CONCLUSION
From all these studies, I conclude that biosensors are cheap, small, and portable devices.
They are capable of being used by semi-skilled operators.
biosensors.ppt (Size: 188 KB / Downloads: 47)
INTRODUCTION
It is an analytical device which converts a biological response into an electrical signal.
It detects, records, and transmits information regarding a physiological change or process.
It determines the presence and concentration of a specific substance in any test solution.
BIO-ELEMENT
Function
To interact specifically with a target compound i.e. the compound to be detected.
It must be capable of detecting the presence of a target compound in the test solution.
The ability of a bio-element to interact specifically with target compound (specificity) is the basis for biosensor.
RESPONSE FROM BIO-ELEMENT
Heat absorbed (or liberated ) during the interaction.
Movement of electrons produced in a radox reaction.
Light absorbed (or liberated ) during the interaction.
Effect due to mass of reactants or products.
TYPES OF BIOSENSOR
Electrochemical biosensor
Optical biosensor
Thermal biosensor
Resonant biosensor
Ion-sensitive biosensor
ELECTROCHEMICAL BIOSENSOR
Principle
Many chemical reactions produce or consume ions or electrons which in turn cause some change in the electrical properties of the solution which can be sensed out and used as measuring parameter.
Classification
(1) Amperometric biosensor
(2) Conductimetric biosensor
(3) Potentiometric biosensor
GLUCOSE BIOSENSOR
Glucose reacts with glucose oxidase(GOD) to form gluconic acid. Two electrons & two protons are also produced.
Glucose mediator reacts with surrounding oxygen to form H2O2 and GOD.
Now this GOD can reacts with more glucose.
Higher the glucose content, higher the oxygen consumption.
Glucose content can be detected by Pt-electrode.
APPLICATIONS OF BIOSENSOR
In food industry, biosensors are used to monitor the freshness of food.
Drug discovery and evaluation of biological activity of new compounds.
Potentiometric biosensors are intended primarily for monitoring levels of carbon dioxide, ammonia, and other gases dissolved in blood and other liquids.
Environmental applications e.g. the detection of pesticides and river water contaminants.
Determination of drug residues in food, such as antibiotics and growth promoters.
Glucose monitoring in diabetes patients.
Analytical measurement of folic acid, biotin, vitamin B12 and pantothenic acid.
Enzyme-based biosensors are used for continuous monitoring of compounds such as methanol, acetonitrile, phenolics in process streams, effluents and groundwater.
CONCLUSION
From all these studies, I conclude that biosensors are cheap, small, and portable devices.
They are capable of being used by semi-skilled operators.