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BIOSENSORS. Prepared by: Samaneh Rahamooz Haghighi PHD student. may2015. Biosensors Section 1. SENSOR. A small device used for direct measurement of a physical quantity of an analyte in a sample matrix Response is continuous and reversible Sample is not perturbed
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BIOSENSORS • Prepared by: • SamanehRahamoozHaghighi • PHD student may2015
SENSOR • A small device used for direct measurement of a physical quantity of an analyte in a sample matrix • Response is continuous and reversible • Sample is not perturbed • Does not require sample collection and preparation • Consists of a transduction element covered by a recognition layer • Recognition layer may be chemical or biological • Recognition layer interacts with target analyte • Transduction element translates the chemical changes into electrical signals
History of Biosensors Dr. Leland Clark Jr “Father of the biosensor” • First described in 1962 by Dr. Leland Clark • 1969 a sensor was invented to detect urea • 1972 the first glucose biosensor commercialized by Yellow Springs Instruments
1980’s ---- Biosensors Would Solve the World's Analytical Needs Industry-- process monitoring and control, particularly food and drink Medicine -- diagnostics, metabolites, hormones Military -- battlefield monitoring of poison gases, nerve agents & people Domestic -- home monitoring of non acute conditions
Introduction • Biosensors ~ $3B • 90% → Glucose testing • 8% - 10% increase in industry per year
Market Size of Biosensors • $7.3 Billion in 2003 • $10.2 Billion in 2007 with a growth rate of about 10.4%
Biosensor Development • 1916 First report on the immobilization of proteins: adsorption of invertase on activated charcoal. • 1956 Invention of the first oxygen electrode [Leland Clark] • 1962 First description of a biosensor: an amperometric enzyme electrode for glucose. [Leland Clark, New York Academy of Sciences Symposium] • 1969 First potentiometric biosensor: urease immobilized on an ammonia electrode to detect urea. [Guilbault and Montalvo] • 1970 Invention of the Ion-Selective Field-Effect Transistor (ISFET).
History of Biosensors • 1975 First commercial biosensor ( Yellow springs Instruments glucose biosensor) • 1975 First microbe based biosensor, First immunosensor • 1976 First bedside artificial pancreas (Miles) • 1980 First fibre optic pH sensor for in vivo blood gases (Peterson) • 1982 First fibre optic-based biosensor • 1983 First surface plasmon resonance (SPR) immunosensor • 1984 First mediated amperometric biosensor: ferrocene used with glucose oxidase for glucose detection
1987 Blood-glucose biosensor launched by MediSenseExacTech • SPR based biosensor by Pharmacia BIACore • 1992 Hand held blood biosensor by i-STAT • 1996 Launching of Glucocard • 1998 Blood glucose biosensor launch by LifeScanFastTake • 1998 Launch of LifeScanFastTake blood glucose biosensor • 1998 Merger of Roche and Boehringer Mannheim to form Roche Diagnostics 1 LifeScan purchases Inverness Medical's glucose testing business for $1.3billion • 2001 To 2015 Microorganism and nano technology to biosensors Quantomdots, nanoparicles, nanowire, nanotube, etc
Your welcome To this subject
What are biosensors? • Devices that analyze biological samples to better understand structure and function and for diagnostics • Uses for biosensors Molecule analysis (DNA and proteins) Food safety Diagnostics Medical monitoring Detection of biological weapons Rapid analysis and detection
Biosensors • Advantages Rapid detection Small volumes of samples needed Can be used by the patient (blood glucose monitor) • Disadvantages Cost May require expertise to use Sample collection can be painful
Types of biosensors • Electrochemical • Temperature sensitive • Photosensitive • Pressure sensitive • Motion sensitive • Chemical sensitive
Category biosensors for biochemical and biological function and structure Biocatalytic (eg, enzymes) Immunological (eg, antibodies) (DNANucleic acid (eg,
Common biosensors • Blood glucose monitors • Heart and blood pressure monitors • Pacemakers • HIV and pregnancy tests
Blood glucose monitors • Used by diabetics to measure blood glucose concentration • Helps patients determine their insulin dose • Uses electrochemistry for detection
A biosensor consists of two components: a bioreceptor and a transducer. The bioreceptor is a biomolecule that recognizes the target analyte whereas the transducer converts the recognition event into a measurable signal. biosensors:
Schematic illustration of a Biosensor bioreceptor transducer amplification signal prossing monitor
Introduction • Bioreceptor: Incorporation of a biomolecule in order to detect something RecognitionLayer Species to be detected (analyte) Transducer Electronics Signal
bio sample :Analyte glutamic acid lactic acid Penicillin toxin many amino acids Peptide vitamin aspirin phosphate Sugar urea cholesterol ethanol
bioreceptor • Enzyme • Antibody • (DNA) • (receptor) • (microorganism) • ( tissue) • (cell) • (organel)
Bioreceptors • Enzyme Enzyme is a large protein molecule that acts as a catalyst in chemical reactions. Enzymes are often chosen as bioreceptors based on their specific binding capabilities as well as their catalytic activity
Enzymes are folded polypeptides (polymers of amino acids) which catalyze chemical reactions without being used up in the conversion of substrates to products. Enzyme Enzymes are proteins with high catalytic activity and selectivity towards substrates.
Advantage and disadvantage of Enzyme Advantage connected to the object High selection catalytic activity increase sensitivity Fastly performance highest consumption Disadvantage Expensive When immobilization enzyme on transducer, loses part of its activitiesBecause inactivity , shortly lose its activities
Bioreceptors • Antibody Antibodies are biological molecules that exhibit very specific binding capabilities for specific structure (antigens). • Antigen membrane It can be recognized by antibody.
biosensors-based antibody also called Immunosensors Antibodies usually immobilize on level of transducer by the amino, carboxyl, aldehyde, sulfide groups. Bonding antibodies to the antigen is stronger and more specific than bonding substrate of the enzyme,.
Advantage High selectiveVery sensitiveTheir bond is very strong. Disadvantage Loss of catalytic effect
Bioreceptors • DNA structure Another biorecognition mechanism involves hybridization of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), which are the building blocks of genetics. Four chemical bases: • adenine(A), guanine (G), • cytosine (C), thymine (T)
Principles of DNA biosensors (Target Sequence) Nucleic acid hybridization Probe DNA is useful for recognation genetic disease , cancer, viral infection
Mark Antibody Probe DNA
The complementarity of adenine-thymine and cytosine-guanosine pairing in DNA forms the basis for the specificity of biorecognition in DNA biosensors (Fig. 2).
Introduction to Biosensors Bioreceptor Transducer Absorption Fluorescence Antibody Optical Interference potentiometric Enzyme Electrochemical amperometric conductimetric Nucleic Acid (DNA) Mass based Cell Temperature based Dielectric properties Electric & Magnetic Permeability properties MIP Voltage or Current
Discriminative Membrance and membranceproce are essential component of a biosensors Selective prevalence Prevent foulingEliminate interferenceControl Emission of analyte Preserving the environment enzymes Protection against mechanical stresses
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