Nanosensors for medicines<br />
Definition of Nanosensors<br /><ul><li>Nanosensor: an extremely small device capable of detecting and responding to physic...
Physical Stimuli: biological and chemical substances, displacement, motion, force, mass, acoustic, thermal, and electromag...
History:
Material first reported in 1956 by Uhlir as an effect from electrochemical polishing studies using a low current density.
Chemical etching with HF/HNO3 also produced porous silicon.
Crystalline etch channels found in early 1970’s by Theunissen.
Pickering et. al. first noted photoluminescence at room temperature.
Canham observed room temperature fluorescence in 1990 and suggested Quantum Confinement as origin of fluorescence.</li></l...
Nanobiosensors <br /><ul><li>A chemical or biological sensor is a device that responds to varying concentrations of a sing...
 Fundamentally, a biosensor is derived from the coupling of a ligand–receptor binding reaction to a signal transducer.</li...
Nano-metals have peculiar optical proprieties due to the size confinement
 Metal nanoparticles have colours that are dependent on their size and surrounding
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Nanosensors for medicines

Nanosensors for medicines
Published on: Mar 3, 2016
Published in: Education      
Source: www.slideshare.net


Transcripts - Nanosensors for medicines

  • 1. Nanosensors for medicines<br />
  • 2. Definition of Nanosensors<br /><ul><li>Nanosensor: an extremely small device capable of detecting and responding to physical stimuli with dimensions on the order of one billionth of a meter
  • 3. Physical Stimuli: biological and chemical substances, displacement, motion, force, mass, acoustic, thermal, and electromagnetic</li></li></ul><li>Current Nanosensors Device<br />Nanostructured materials - e.g. porous silicon<br />Nanoparticles<br />Nanoprobes<br />Nanowirenanosensors<br />Nanosystems<br /><ul><li>Cantilevers, NEMS</li></li></ul><li>Porous Silicon<br /><ul><li>Description: Porous silicon is identical to the silicon used in many technological applications today, but its surface contains tiny pores ranging from < 2nm to microns, that can absorb and emit light.
  • 4. History:
  • 5. Material first reported in 1956 by Uhlir as an effect from electrochemical polishing studies using a low current density.
  • 6. Chemical etching with HF/HNO3 also produced porous silicon.
  • 7. Crystalline etch channels found in early 1970’s by Theunissen.
  • 8. Pickering et. al. first noted photoluminescence at room temperature.
  • 9. Canham observed room temperature fluorescence in 1990 and suggested Quantum Confinement as origin of fluorescence.</li></li></ul><li>Classification of porous silicon<br />A: Nanoporous silicon - (features < 5nm)<br />B: Mesoporous silicon - (features 5nm - 100nm)<br />C: Macroporous silicon - (features > 100nm)<br />D: Pores generated by electrical breakdown<br />
  • 10. Nanobiosensors <br /><ul><li>A chemical or biological sensor is a device that responds to varying concentrations of a single analyte or a specific class of chemicals.
  • 11. Fundamentally, a biosensor is derived from the coupling of a ligand–receptor binding reaction to a signal transducer.</li></li></ul><li>Colorimetric Gold Nanosensor<br /><ul><li>Gold at the nanoscale has different properties than bulk gold
  • 12. Nano-metals have peculiar optical proprieties due to the size confinement
  • 13. Metal nanoparticles have colours that are dependent on their size and surrounding
  • 14. This allows using solutions of metal nanoparticles (colloids) as sensors</li></li></ul><li>Colorimetric Gold Nanosensor for Medicines<br />The energy of LSPR's is sensitive to the dielectric functionof the material and the surroundings and to the shape and size of the nanoparticle:<br /><ul><li> distance between nanoparticles in the colloid (aggregation)
  • 15. attachment of a ligand on the surface of the nanoparticles</li></ul>Metal colloids can be used as sensors:<br /><ul><li>In a surface plasmonic sensor, metal nanoparticles are immobilized on a surface. The sensing results in a change in refractive index which determines a change in the LSPR signal.</li></li></ul><li>Colorimetric Gold Nanosensor for Medicines<br /><ul><li>Metal colloids can be used as sensors:
  • 16. In a surface plasmonic sensor, metal nanoparticles are immobilized on a surface. The sensing results in a change in refractive index which determines a change in the LSPR signal.</li></li></ul><li>Nanoprobes<br /><ul><li>PEEBBLE probes (Probe Embedded By Biologically Localized Encapsulation)
  • 17. Sphere shaped 10nm+
  • 18. pH, calcium, magnesium, oxygen, potassium</li></li></ul><li>Nanoprobe<br />Nanosensor Probes Single Living Cells<br /><ul><li>A 50-nm-diameter nanosensor probe carrying a laser beam (blue) penetrates a living cell to detect the presence of a product indicating that the cell has been exposed to a cancer-causing substance.
  • 19. This nanosensor of high selectivity and sensitivity was developed by a research group led by Tuan Vo-Dinh and his coworkers Guy Griffin and Brian Cullum.</li></li></ul><li>NanowireNanosensor for Pharmaceutical Industry<br />NW Nanosensorfor pH detection <br /><ul><li>A: Schematic illustrating the conversion of a NWFET into NW nanosensors for pH sensing. The NW is contacted with two electrodes, a source (S) and drain (D), for measuring conductance. Zoom of the APTES-modified SiNW surface illustrating changes in the surface charge state with pH.
  • 20. B: Real-time detection of the conductance for an APTES modified SiNW for pHs from 2 to 9
  • 21. C: Plot of the conductance versus Ph
  • 22. D: The conductance of unmodified SiNW (red) versus pH.</li></li></ul><li>NanowireNanosensor for Pharmaceutical Industry<br />