Biosensors

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biosensors, types of biosensors

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Biosensors

  1. 1. BIOSENSORS BY, A. POOJA SHUKLA M. Tech (I yr) 1821310006 SRM UNIVERSITY
  2. 2. WHAT IS SENSOR…?? A sensor is a converter that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument.
  3. 3.  Nanosensors are any biological, chemical, or surgical sensory points used to convey information about nanoparticles to the macroscopic world.  medicinal purposes  nanoproducts, such as computer chips that work at the nanoscale and nanorobots. WHAT IS NANO - SENSOR…??
  4. 4. WHAT IS BIO - SENSOR…?? A biosensor is an analytical device, used for the detection of an analyte, that combines a biological component with a physicochemical detector.
  5. 5. Father of the Biosensor Professor Leland C Clark Jnr 1918–2005  A device incorporating a biological sensing element either intimately connected to or integrated within a transducer.  Recognition based on affinity between complementary structures like:  enzyme-substrate, antibody-antigen and receptor-hormone complex.  Selectivity and specificity depend on biological recognition systems connected to a suitable transducer. BIO - SENSOR…??
  6. 6.  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 - SENSOR…??
  7. 7. Basic priciple of biosensor involved in three element :-  First biological recognization element which highly specific towards the biological material analytes produces.  Second transducesrs detect and transduces signal from biological target - receptor molecule to electrical signal which is due to reaction occur.  Third after transduction sinal from biological to electrical signal where its amplification is necessary and takes place and read out in detector after processing the values are displayed for monitor and controlling the system . BASIC PRINCIPLE OF BIOSENSOR
  8. 8. BASIC PRINCIPLE OF BIOSENSOR
  9. 9.  The biological material is immobilized and a contact is made between the immobilized biological material and the transducer  The analyte binds to the biological material to form a bound analyte which in turn produces the electronic response that can be measured.  Sometimes the analyte is converted to a product which could be associated with the release of heat, gas (oxygen), electrons or hydrogen ions. The transducer then converts the product linked changes into electrical signals which can be amplified and measured BASIC PRINCIPLE OF BIOSENSOR
  10. 10. Detector COMPONENTS OF BIOSENSOR
  11. 11. Microorganism Tissue Cell Organelle Nucleic Acid Enzyme Enzyme Component Receptor Antibody The component used to bind the target molecule. Must be highly specific, stable under storage conditions, and immobilized. 1st COMPONENT – BIOLOGICAL ELEMENT
  12. 12.  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. 1st COMPONENT – BIOLOGICAL ELEMENT
  13. 13. Acts as an interface, measuring the physical change that occurs with the reaction at the bioreceptor then transforming that energy into measurable electrical output. 2nd COMPONENT – PHYSIOCHEMICAL TRANSDUCER
  14. 14. Signals from the transducer are passed to a microprocessor where they are amplified and analyzed. The data is then converted to concentration units and transferred to a display or/and data storage device. 3rd COMPONENT – DETECTOR
  15. 15. PRINCIPLE OF DETECTION PIEZOELECTRIC Measures change in mass ELECTRO-MECHANICAL Measures change in electric distribution OPTICAL Measures change in light intensity CALORIMETRIC Measures change in heat
  16. 16. a- Bio-element b- Transducer Figure. Schematic Diagram of Biosensor c- Amplifier d- Processor e- Display WORKING OF BIOSENSOR
  17. 17.  Biosensors basically involve the quantitative analysis of various substances by converting their biological actions into measurable signals.  Generally the performance of the biosensors is mostly dependent on the specificity and sensitivity of the biological reaction, besides the stability of the enzyme. HOW DOES THEY WORK…??
  18. 18. Analyte Sample handling/preparation Detection Signal Analysis Response HOW DOES THEY WORK…??
  19. 19.  The output signal must be relevant to measurement environment.  The functional surface must be compatible with the transducer.  High specificity and selectivity (low interference).  Sufficient sensitivity and resolution . IDEAL BIOSENSOR
  20. 20.  Sufficient accuracy and repeatability  Sufficient speed of response  Sufficient dynamic range.  Insensitivity to environmental interference or their effects must be compensated IDEAL BIOSENSOR
  21. 21. 1. LINEARITY - Linearity of the sensor should be high for the detection of high substrate concentration. 2. SENSITIVITY - Value of the electrode response per substrate concentration. 3. SELECTIVITY - Chemicals Interference must be minimised for obtaining the correct result. 4. RESPONSE TIME - Time necessary for having 95% of the response. BASIC CHARACTERISTICS OF BIOSENSOR
  22. 22. BIOSENSOR TECHNOLOGY
  23. 23.  Based on bioreceptors Enzyme biosensor Microbial biosensor Affinity biosensor  Based on transducer Potentiometric Amperometric conductometric Optical Acoustic or piezoelectric etc. TYPES OF BIOSENSOR
  24. 24. • Colorimetric for color: Measure change in light adsorption as reactants are converted to products. • Photometric for light intensity: Photon output for a luminescent or fluorescent process can be detected with photomultiplier tubes or photodiode systems. OPTICAL BIOSENSORS
  25. 25. If the enzyme catalyzed reaction is exothermic, two thermistors may be used to measure the difference in resistance between reactant and product and hence the analyte concentration. CALORIMETRIC BIOSENSORS
  26. 26. For voltage: Change in distribution of charge is detected using ion-selective electrodes, such as pH- meters. POTENTIOMETRIC BIOSENSORS
  27. 27. The change in frequency is proportional to the mass of absorbed material. Piezo-electric devices use gold to detect the specific angle at which electron waves are emitted when the substance is exposed to laser light or crystals, such as quartz, which vibrate under the influence of an electric field. PIEZO - ELECTRIC BIOSENSORS
  28. 28.  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 ELECTROCHEMICAL BIOSENSORS
  29. 29. •Amperometric for applied current: Movement of e- in redox reactions detected when a potential is applied between two electrodes. •Potentiometric for voltage: Change in distribution of charge is detected using ion-selective electrodes, such as pH-meters. •Conductimetric for impedance ELECTROCHEMICAL BIOSENSORS
  30. 30.  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. AMPEROMETRIC BIOSENSORS
  31. 31.  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. GLUCOSE BIOSENSORS
  32. 32.  Steps involved in electrochemical DNA hybridization biosensors:  Formation of the DNA recognition layer  Actual hybridization event  Transformation of the hybridization event into an electrical signal ELECTROCHEMICAL DNA BIOSENSORS
  33. 33. Motivated by the application to clinical diagnosis and genome mutation detection  Electrodes  Chips  Crystals DNA BIOSENSORS TYPES
  34. 34. Pregnancy test - Detects the hCG protein in urine. EXAMPLE OF BIOSENSOR
  35. 35. Glucose monitoring device (for diabetes patients) Monitors the glucose level in the blood. EXAMPLE OF BIOSENSOR
  36. 36. BIOSENSORS AT NANOSCALE
  37. 37. WHAT IS NANO BIOSENSOR…?? Comparison of nano-rangeNano - very small Includes many fields Its the Miniatured Biology Nanotechnology- manipulating matter at nanoscale.  BIO-SENSOR AT NANOSCALE
  38. 38. Nanoparticles have novel property. Integration of material science, molecular engineering, chemistry and biotechnology. Improve the sensitivity and specificity of biomolecule detection Efficient biomolecular recognition, pathogenic diagnosis and environment monitoring. WHY NANO BIOSENSOR…??
  39. 39. PROPERTIES PARTICLES USED  Gold nanoparticle  Carbon Nanotubes  Magnetic particles  Quantum dots Unique • physical • chemical, • mechanical, • magnetic and • optical properties, • markedly enhance the sensitivity and specificity of detection. NANOPARTICLES…??
  40. 40.  Allows the placement of small structures with precision, simplicity and low cost.  Small particles high efficiency  Leads to economic growth  Enhances national security  Improves the quality of life  Job oppurtunities NEED FOR NANOPARTICLES…??
  41. 41. Material Medical •Stronger •End of Illnesses (i.e. cancer, heart disease) •Lighter •Universal Immunity (i.e. aids, flu) •Cheaper •Body Sculpting (i.e. change your appearance) •Durable •Precise ADVANTAGE OF USING NANOPARTICLES…??
  42. 42. Dr. Michael Strano at the University of Illinois, "We have developed molecular sheaths around the nanotube that respond to a particular chemical and modulate the nanotube's optical properties." CURRENT RESEARCH SPOT-NOSED Project: A layer of olfactory proteins on a nanoelectrode could react with low-concentration odorants. This technology could be used by doctors to diagnose diseases at earlier stages.
  43. 43. Nanosphere lithography (NSL) derived triangular Ag nanoparticles were used to detect streptavidin down to one picomolar concentrations. CURRENT RESEARCH The School of Biomedical Engineering has developed an anti-body based piezoelectric nanobiosensor to be used for anthrax, HIV hepatitis detection.
  44. 44.  Food Analysis  Study of biomolecules and their interaction  Drug Development  Crime detection  Medical diagnosis (both clinical and laboratory use)  Environmental field monitoring  Quality control  Industrial Process Control  Detection systems for biological warfare agents  Manufacturing of pharmaceuticals and replacement organs APPLICATIONS OF BIOSENSORS
  45. 45. NANO-NOSE:  Food quality check using nanoparticles.  Detection of various protein.  For detection of diseases.  Various proteins are sensed out in body fluids.  Advantage:  Highly sensitive  96% accuracy  Quick detection APPLICATIONS AT NANOSCALE
  46. 46. Biological Applications DNA Sensors: Genetic monitoring, disease diagnosis Immunosensors: HIV, Hepatitis, other viral diseases drug testing, environmental monitoring… CURRENT APPLICATIONS
  47. 47. Biological Application Cell-based Sensors: functional sensors, drug testing… Point-of-care sensors: blood, urine, electrolytes, gases, steroids,drugs, hormones, proteins, other… CURRENT APPLICATIONS
  48. 48. Biological Applications Bacteria Sensors: (E-coli, streptococcus, other): food industry,medicine, environmental, other. Enzyme sensors: diabetics, drug testing, other. CURRENT APPLICATIONS
  49. 49.  Health and safety issues  Nanoparticles can cause serious illness or damage human body.  Untraceable destructive weapons of mass destruction.  Social & Political issues  Advisability of increasing scope of the technology creates political dilemma  Creates social strife through increasing wealth gap  Loss of jobs (in manufacturing, farming, etc)  Carbon Nanotubes could cause infection of lungs  Oil & Diamonds could become worthless DISADVANTAGES
  50. 50.  Examples of Future Use of NT  Electronic Paper  Nokia Morph  Contact Lens FUTURE OF NANOBIOTECHNOLOGY
  51. 51. FUTURE OF NANOBIOTECHNOLOGY
  52. 52. THANK YOU…!!

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