7 nanosensors
Download as PPTX, PDF14 likes13,566 views
Nanobiosensors use biological components on the nano-scale to detect target molecules. They consist of a bioreceptor element for molecular recognition connected to a transducer that converts the biological response into a measurable signal. Common transduction methods include optical, electrochemical and mechanical. Examples are nanowire field effect sensors that detect binding as a change in electrical conductivity, and cantilever sensors that detect binding as a change in resonant frequency through surface stress. Nanobiosensors show potential for applications in healthcare diagnostics, environmental monitoring, and more.
![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).
• 1972/5 First commercial biosensor: Yellow Springs Instruments glucose
biosensor.
• 1976 First bedside artificial pancreas [Clemens et al.]
• 1980 First fiber optic pH sensor for in vivo blood gases.
• 1982 First fiber optic-based biosensor for glucose
• 1983 First surface plasmon resonance (SPR) immunosensor.
• 1987 Launch of the blood glucose biosensor[ MediSense]](https://image.slidesharecdn.com/7-nanosensors-121127145044-phpapp02/85/7-nanosensors-6-320.jpg)
7 nanosensors
- 1. NANOBIOSENSORS biosensors on the nano-scale size
- 2. BIOSENSORS • 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 , receptor- hormone complex. • Selectivity and specificity depend on biological recognition systems connected to a suitable transducer.
- 6. 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). • 1972/5 First commercial biosensor: Yellow Springs Instruments glucose biosensor. • 1976 First bedside artificial pancreas [Clemens et al.] • 1980 First fiber optic pH sensor for in vivo blood gases. • 1982 First fiber optic-based biosensor for glucose • 1983 First surface plasmon resonance (SPR) immunosensor. • 1987 Launch of the blood glucose biosensor[ MediSense]
- 7. Theory
- 8. Biosensors Bio-receptor Transducer Molecular Optical DNA Bio-luminescence Protein Photoluminescence Glucose Electrical Etc….. Electronic Cell Electrochemical Bio-mimetic Mechanical Resonance Bending
- 9. Bio-receptor/ analyte complexes • Antibody/antigen interactions, • Nucleic acid interactions • Enzymatic interactions • Cellular interactions • Interactions using bio-mimetic materials (e.g. synthetic bio-receptors).
- 10. Signal transduction methods 1. Optical measurements - luminescence, absorption, surface plasmon resonance 2. Electrochemical - potentiometric, amperometric, etc. 3. Electrical – transistors, nano-wires, conductive gels etc. 4. Mass-sensitive measurements- surface acoustic wave, microcantilever, microbalance, etc.).
- 11. Electrical sensing Nano-bio interfacing how to translate the biological information onto electrical signal ? • Electrochemical – Redox reactions • Electrical – FET (Nano wires; Conducting Electro-active Polymers)
- 12. Electrical sensors FET based methods – FET – Field Effect Transistors ISFET – Ion Sensitive FET CHEMFET – Chemically Sensitive FET SAM-FET – Self Assembly Monolayer Based FET K Corrente elettrica
- 13. Nanowires Biosensors Field Effect Nanobiosensors (FET) • Functionalize the nano-wires • Binding to bio-molecules will affect the nano-wires conductivity.
- 14. Nanowire Field Effect Nanobiosensors (FET) Sensing Element Semiconductor channel (nanowire) of the transistor. • The semiconductor channel is fabricated using nanomaterials such carbon nanotubes, metal oxide nanowires or Si nanowires. • Very high surface to volume radio and very large portion of the atoms are located on the surface. Extremely sensitive to environment
- 15. NANOWIRE
- 16. NANOTUBE
- 20. NW grow across gap between electrodes Growing NW connect to the second electrode
- 21. Form trench in Si and NW grows NW connects to opposite Deposit catalyst perpendicular sidewall
- 24. Schematic shows two nanowire devices, 1 and 2, where the nanowires are modified with different antibody receptors. Specific binding of a single virus to the receptors on nanowire 2 produces a conductance change (Right) characteristic of the surface charge of the virus only in nanowire 2. When the virus unbinds from the surface the conductance returns to the baseline value.
- 33. Other optical methods • Surface Plasmon Resonance (SPR)
- 34. Surface Plasmon Resonance (SPR)
- 37. Bio-molecule sensing Detection of biomolecules by simple mechanical transduction: target molecule - cantilever surface is covered receptor molecule by receptor layer gold (functionalization) SiNx cantilever - biomolecular interaction between receptor and target molecules (molecular recognition) target binding deflection d - interaction between adsorbed molecules induces surface stress change bending of cantilever
- 39. resonance frequency mass-sensitive detector A 1 k f1 2 m eff f1 f1 f A 1 k m f2 2 m eff m f2 f2 f A mass sensitive resonator transforms an additional mass loading into a resonance frequency shift mass sensor B. Kim et al, Institut für Angewandte Physik - Universität Tübingen
- 40. Magnetic sensing • magnetic fields to sense magnetic nano- particles that have been attached to biological molecules.
- 41. Stabilization of Magnetic Particles with various Streptavidin Conc. Ligand-functionalized Magnetic nano - particle Analyte 10 min reaction None 1 ng/ml 100 ng/ml 100 g/ml Cleaning 5 min deposition Anti-analyte Antibody T. Osaka, 2006
- 42. Magnetic sensing Sensing plate Magnetic head Activated pixel Idle pixel Magnetic field sensor Magnetic sensing
- 43. Magnetic-optic sensing Polarization Sensing plate Optics Detector Light source Activated pixel Idle pixel Polarizer
- 44. Applications of Nanobiosensors Biological Applications • DNA Sensors; Genetic monitoring, disease • Immunosensors; HIV, Hepatitis,other viral diseas, drug testing, environmental monitoring… • Cell-based Sensors; functional sensors, drug testing… • Point-of-care sensors; blood, urine, electrolytes, gases, steroids, drugs, hormones, proteins, other… • Bacteria Sensors; (E-coli, streptococcus, other): food industry, medicine, environmental, other. • Enzyme sensors; diabetics, drug testing, other. Environmental Applications • Detection of environmental pollution and toxicity • Agricultural monitoring • Ground water screening • Ocean monitoring
- 45. Optical detection of analyte binding
- 46. Fluorescence sensors • Biological materials – using photo-biochemical reaction – – Photo induced luminescence – photoluminescence – example: Green Fluorescent Proteins (GFP) – Chemically induced florescence – Bioluminescence - Example: Lux • Physical effects – Luminescence from nano- structured materials – Semiconductor nano-particles,