Biosensor By Devender Arora,,,

BIOSENSOR

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Devender Arora 

Gourav Girdhar 

Sonia

Yavika

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CONTENT DEFINITION PARTS IMPORTANCE

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Biosensor? 

What its mean?

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A Biosensor is an analytical device which convert a biological response into an electrical signal on which Biosensor Based<< >>Basic principle 

Biosensors Combine a biological compound with a transducer

Que: What is a transducer? Ans: Conventional enzyme electrodes use bulky electrochemical devices as transducers, such as the oxygen electrode and hydrogen electrode

It consists of 3 parts: 

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the sensitive biological element (biological material (eg. tissue, microorganisms, organelles, cell receptors, enzymes, antibodies, nucleic acids, etc), a biologically derived material or biomimic) The sensitive elements can be created by biological engineering. the transducer or the detector element (works in a physicochemical way; optical, piezoelectric, electrochemical, etc.) that transforms the signal resulting from the interaction of the analyte with the biological element into another signal (i.e., transducers) that can be more easily measured and quantified; associated electronics or signal processors that is primarily responsible for the display of the results in a user-friendly way

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Why biosensor are important ? biosensor are important? Biosensor are important?

1. Important tools in food safety, diagnostics, medical monitors, and detection systems for biological warfare agents.  2. important devices offering analytical simplicity both in and outside the analytical laboratory. 

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3. selective, rapid and sensitive instruments for determination of chemical and biochemical targets.

Classification -1 Types of Biological Recognition Name of the BIOSENSOR

Enzymes Proteins Antibodies DNA Organelles Microbial cells

Elements Enzyme electrode Immunosensor DNA sensor Microbial sensor

Classification-2 Types of Transducers Electrochemical

Measured Property Potentiometric Amperometric Voltametric Electrical Surface conductivity Electrolyte conductivity Optical Fluorescence Adsorption Reflection Mass sensitive Resonant frequency of piezocrytals Thermal Heat of reaction Heat of adsorption

Basic Characteristics of a biosensor 1. LINEARITY: Maximum linear value of the sensor calibration curve. Linearity of the sensor must be high for the detection of high substrate concentration. 2. SENSITIVITY: The value of the electrode response per substrate concentration. 3. SELECTIVITY: Interference of chemicals must be minimized for obtaining the correct result. 4. RESPONSE TIME: The necessary time for having 95% of the response.

Uses of Biosensors 1.Environmental Monitoring 2.Military 3.Law Enforcement 4.Medical

Present Applications of Biosensors 1. Medical Care (both clinical and laboratory use) 2. The determination of food quality 3. The detection of environmental pollutants 4. Industrial Process Control

Applications (cont’d.) 5. Biosensors in process control will be able to measure materials in the process flow of temperature, pressure and the acidity readings. 6. The development of biosensors in industry can improve manufacturing techniques, which would allow for a wider range of sensing molecules to be produced at a cheaper rate. 7. In the field of medicine, tumor cells are used as a biosensor to monitor chemotherapeutic drug susceptibilities. 8. Biosensors also play a role in the manufacturing of pharmaceuticals and replacement organs such as an artificial pancreas for diabetics.

A successful biosensor must possess at least some of the following beneficial features: The biocatalyst must be highly specific for the purpose of the analyses, be stable under normal storage conditions and, except in the case of colorimetric enzyme strips and dipsticks (see later), show good stability over a large number of assays (i.e. much greater than 100). The reaction should be as independent of such physical parameters as stirring, pH and temperature as is manageable. This would allow the analysis of samples with minimal pre-treatment. If the reaction involves cofactors or coenzymes these should, preferably, also be co-immobilised with the enzyme The response should be accurate, precise, reproducible and linear over the useful analytical range, without dilution or concentration. It should also be free from electrical noise. If the biosensor is to be used for invasive monitoring in clinical situations, the probe must be tiny and biocompatible, having no toxic or antigenic effects. If it is to be used in fermenters it should be sterilisable. This is preferably performed by autoclaving but no biosensor enzymes can presently withstand such drastic wet-heat treatment. In either case, the biosensor should not be prone to fouling or proteolysis. The complete biosensor should be cheap, small, portable and capable of being used by semi-skilled operators. There should be a market for the biosensor. There is clearly little purpose developing a biosensor if other factors (e.g. government subsidies, the continued employment of skilled analysts, or poor customer perception) encourage the use of traditional methods and discourage the decentralisation of laboratory testing.

Searching for biomarkers that can warn of diseases such as cancer while they are still in their earliest stage is likely to become far easier thanks to an innovative biosensor chip developed by Stanford University researchers. The magnetonanosensor has 64 sensors capable of detecting up to 64 different proteins. In the center of the chip is the well that holds the fluid of interest. The reader that measures the magnetic fields of the sensors is in the background. Thumb and fingers are courtesy of Richard Gaster, M.D./Ph.D. candidate in both bioengineering and the school of medicine. Credit: Linda Cicero, Stanford News Service The sensor is up to 1,000 times more sensitive than any technology now in clinical use, is accurate regardless of which bodily fluid is being analyzed and can detect biomarker proteins over a range of concentrations three times broader than any existing method, the researchers say. The magnetonanosensor has 64 sensors capable of detecting up to 64 different proteins. In the center of the chip is the well that holds the fluid of interest. The reader that measures the magnetic fields of the sensors is in the background. Thumb and fingers are courtesy of Richard Gaster, M.D./Ph.D. candidate in both bioengineering