BIOSENSOR : BIOSENSOR PREPARED BY
B.E. CHEMICAL 4TH
ROLL NO. 24
SCET, SURAT GUIDED BY
SCET, SURAT CONTENTS : CONTENTS Introduction
Basic components of Biosensor
Working of Biosensor
Types of Biosensor
Applications of Biosensor
References INTRODUCTION : 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
It determines the presence and concentration of a specific substance in any test solution. BASIC COMPONENTS : BASIC COMPONENTS Bio-element
Transducer component BIO-ELEMENT : BIO-ELEMENT It is a typically complex chemical system usually extracted or derived directly from a biological organism.
Polysaccharide Nucleic Acid BIO-ELEMENT : 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. TRANSDUCER : TRANSDUCER Function :
To convert biological response in to an electrical signal.
Piezoelectric WORKING OF BIOSENSOR : WORKING OF BIOSENSOR a- Bio-element
Figure. Schematic Diagram of Biosensor c- Amplifier
e- Display RESPONSE FROM BIO-ELEMENT : 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 : TYPES OF BIOSENSOR Electrochemical biosensor
Ion-sensitive biosensor ELECTROCHEMICAL 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.
(1) Amperometric biosensor
(2) Conductimetric biosensor
(3) Potentiometric biosensor AMPEROMETRIC BIOSENSOR : AMPEROMETRIC BIOSENSOR Measuring parameter : Electric current
Based on oxidase enzymes that generate H2O2 and consume oxygen.
Formation of H2O2 can be detected by the help of Pt-electrode. GLUCOSE 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 : 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.
CONTINEU…… Slide 15: 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 : 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. REFERENCES : REFERENCES International Union of Pure and Applied Chemistry. "Biosensor". Compendium of Chemical Terminology Internet edition.
Encyclopedia of chemical technology, by Kirth and Othmer (vol.4) page no.208-220 Slide 18: THANK YOU