logging in or signing up Quantum Dot Sensors rithraj Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 4026 Category: Science & Tech.. License: All Rights Reserved Like it (6) Dislike it (0) Added: December 05, 2008 This Presentation is Public Favorites: 2 Presentation Description this is a seminar delivered by Rithesh Raj about different kind of modern sensors based on quantum dots . Comments Posting comment... Premium member Presentation Transcript Slide 1: Quantum Dot sensors RITHESH RAJ D REG.NO. 07MSS022 email . rithraj@gmail.com Introduction : Introduction Quantum Dots are small particles of a semiconductor material. Typical dimensions ranging for most of the systems from 1 nm to 10 nm Just as in an atom, the energy levels are quantized due to the confinement of electrons. Properties of quantum dots : Properties of quantum dots Unique Spectral properties Broad absorption Narrow emission Wavelength depends on size Properties of quantum dots Broad excitation spectrum, narrow emission spectrum: : Properties of quantum dots Broad excitation spectrum, narrow emission spectrum: Visible spectrum : Visible spectrum Ten distinguishable emission colors of ZnS-capped CdSe QDs excited with a near-UV lamp. Properties of quantum dots : Properties of quantum dots Photostability QDs will absorb any photon with energy hν > E1S1s High quantum yield emission broadening Structure : Structure Core CdSe, CdTe, PbS, PbSe, InGaP Shell ZnS, CdS Coating Water soluble lipid coating for in vivo applications Structure : Structure Size Scale : Size Scale Temperature sensor : Temperature sensor core-shell CdSe/ZnS nanocrystals entrapped in – PLMA Source 488nm laser Photoluminescence intensity increased in the order of -1.3% per ºC. Chemical sensors : Chemical sensors the luminescence of core QDs can be very sensitive to the surrounding chemical environment. CdS nanoparticles- Zn2+, Cu2+ polyphosphate-capped QD thioglycerol-capped QD Biosensors : Biosensors Making hydrophobic quantum dots bio-compatible Various methods for making them water-soluble Derivatizing surface with mercaptoacetic acid Encapsulating in phospholipid micelles Derivatizing surface with DHLA Coating them with amine-modified polyacrylic acid Slide 15: Quantum dots and imaging Wu et al. 2003 Slide 16: Quantum dots v/s other fluorescent probes Photostability (quantum dots do not photobleach) Red: qdot 605 Conjugate Green: Alexa488 Conjugate Wu et al. 2003 Slide 17: Quantum dots v/s other fluorescent probes Brighter than other fluorophores Larson et al. 2003 Quantum dots Fluorescein Optical Fiber Sensor Using Quantum Dots : Optical Fiber Sensor Using Quantum Dots CdSe QD-doped phosphate glass was used as the sensing mechanism. a white light source. The temperature dependent absorption spectra was then monitored using a second fiber Spectral Bar Codes : Spectral Bar Codes Slide 20: Conclusion Quantum Dots are amazing little wonders that allow us to tune them and attach them how we wish. We can use them for detections of almost anything we might want to find. In the years to come they have a great potential to become as integrated in to our lives. References : References Optical Fiber Sensing Using Quantum Dots by Pedro Jorge, Manuel António Martins, Tito Trindade, José Luís Santos and Faramarz Quantum Dots by Chance Harenza QUANTUM DOTS BASED RAD-HARD COMPUTING AND SENSORS by A. Fijany, G. Klimeck, R. Leon Thank you : ? Thank you You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
Quantum Dot Sensors rithraj Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 4026 Category: Science & Tech.. License: All Rights Reserved Like it (6) Dislike it (0) Added: December 05, 2008 This Presentation is Public Favorites: 2 Presentation Description this is a seminar delivered by Rithesh Raj about different kind of modern sensors based on quantum dots . Comments Posting comment... Premium member Presentation Transcript Slide 1: Quantum Dot sensors RITHESH RAJ D REG.NO. 07MSS022 email . rithraj@gmail.com Introduction : Introduction Quantum Dots are small particles of a semiconductor material. Typical dimensions ranging for most of the systems from 1 nm to 10 nm Just as in an atom, the energy levels are quantized due to the confinement of electrons. Properties of quantum dots : Properties of quantum dots Unique Spectral properties Broad absorption Narrow emission Wavelength depends on size Properties of quantum dots Broad excitation spectrum, narrow emission spectrum: : Properties of quantum dots Broad excitation spectrum, narrow emission spectrum: Visible spectrum : Visible spectrum Ten distinguishable emission colors of ZnS-capped CdSe QDs excited with a near-UV lamp. Properties of quantum dots : Properties of quantum dots Photostability QDs will absorb any photon with energy hν > E1S1s High quantum yield emission broadening Structure : Structure Core CdSe, CdTe, PbS, PbSe, InGaP Shell ZnS, CdS Coating Water soluble lipid coating for in vivo applications Structure : Structure Size Scale : Size Scale Temperature sensor : Temperature sensor core-shell CdSe/ZnS nanocrystals entrapped in – PLMA Source 488nm laser Photoluminescence intensity increased in the order of -1.3% per ºC. Chemical sensors : Chemical sensors the luminescence of core QDs can be very sensitive to the surrounding chemical environment. CdS nanoparticles- Zn2+, Cu2+ polyphosphate-capped QD thioglycerol-capped QD Biosensors : Biosensors Making hydrophobic quantum dots bio-compatible Various methods for making them water-soluble Derivatizing surface with mercaptoacetic acid Encapsulating in phospholipid micelles Derivatizing surface with DHLA Coating them with amine-modified polyacrylic acid Slide 15: Quantum dots and imaging Wu et al. 2003 Slide 16: Quantum dots v/s other fluorescent probes Photostability (quantum dots do not photobleach) Red: qdot 605 Conjugate Green: Alexa488 Conjugate Wu et al. 2003 Slide 17: Quantum dots v/s other fluorescent probes Brighter than other fluorophores Larson et al. 2003 Quantum dots Fluorescein Optical Fiber Sensor Using Quantum Dots : Optical Fiber Sensor Using Quantum Dots CdSe QD-doped phosphate glass was used as the sensing mechanism. a white light source. The temperature dependent absorption spectra was then monitored using a second fiber Spectral Bar Codes : Spectral Bar Codes Slide 20: Conclusion Quantum Dots are amazing little wonders that allow us to tune them and attach them how we wish. We can use them for detections of almost anything we might want to find. In the years to come they have a great potential to become as integrated in to our lives. References : References Optical Fiber Sensing Using Quantum Dots by Pedro Jorge, Manuel António Martins, Tito Trindade, José Luís Santos and Faramarz Quantum Dots by Chance Harenza QUANTUM DOTS BASED RAD-HARD COMPUTING AND SENSORS by A. Fijany, G. Klimeck, R. Leon Thank you : ? Thank you