1 DEVELOPING THE NANOSCIENCE WORKFORCE OF THE FUTURE: LINKING NANOTECHNOLOGY AND RESEARCH TO THE ENVIRONMENT

2 KNOWLEDGE  TECHNOLOGYDISCOVERY  KNOWLEDGE KNOWLEDGE  TECHNOLOGY TECHNOLOGY  SOCIETY SOCIETY  DISCOVERY?? A cycle driven by curiosity and exploration, tempered by need and prejudice

3 application of science to developing new materials and processes by NANOSCALE CONCEPTS What is Nanotechnology? Nanotechnology is defined as the application of science to developing new materials and processes by manipulating molecular and atomic particles.

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5 Nanotechnology Will Change Our World

6 MULTI-DISCIPLINARY AND CREATIVITY Merrill-Lynch review

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8 Two approaches to manufacture of nanomaterials(RS&RAD, 2004) Bottom-Up Top-down Chemical Synthesis Self-assembly Positional assembly Lithography Cutting, Etching, Grinding Technique Particle molecules Crystals, Films, Tubes Electronic devices and chip masks Precision engineered surfaces Material Experimental atomic or molecular devices Cosmetics, Fuel additives Quantum well lasers, computer chips, Micro-electro-mechanical systems (MEMS) High quality optical mirrors Application Displays Independent approaches have converged in terms of feature size and quality achieved

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11 Inspection and Manipulation of Single MoleculesNEW MICROSCOPY OPENS THE WAY TO NANOTECHNOLOGY This is the size scale of interest to nanoscience and nanotechnology; ~ meters in length or less or about 1/10,000 width of a human hair

12 Founders – Atomic Force MethodGerd Binning Heinrich Rohrer

13 Atomic Force MicroscopyAFM invented in 1986 by g. Binning. STM in 1982 by H. Roher and G. Binning

14 Lateral Force Mode involvesonly x-y movement In contact mode x-y and z movement is involved

15 Modifying a “wire” Ros et al., PSI Annual Report, 1999.

16 Binding force measurementsRos et al., PSI Annual Report, 1999.

17 Nano wire manipulation on polymer film: The images are taken in intermittent contact mode while the wire has been moved successively with contact mode by applying a constant force of 2.2 nN. Scan field 400 nm X 550 nm, z-range nm (http://www.jpk.com/spm/gallery1.htm#litho)

18 (another form of carbon compound)WIRING: CARBON NANOTUBE (another form of carbon compound)

19 Columbia – Chem. Eng.

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23 Li and Tan, Nano Letters, 2 (2002) 315.

24 Li and Tan, Nano Letters, 2 (2002) 315.

25 INSTITUTE OF PHYSICS PUBLISHING NANOTECHNOLOGYNanotechnology 13 (2002) R15–R28 PII: S (02)52701-X TUTORIAL Natural strategies for the molecular engineer Philip Ball Nature, 4-6 Crinan St, London N1 9XW, UK Received 23 August 2002 Published 11 September 2002 Online at stacks.iop.org/Nano/13/R15

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28 Tools to measure position – THE “MOLECULAR RULER”Cardullo, Microscopy and Analysis, Issue 53 (2002) 5.

29 Inorganic Semiconductor Quantum Dots (QD)Colloidal semiconductor nanocrystals Unique optical properties arising from size effects Broad ABS spectra; narrow/symmetric emission spectra, stable, resistant to photobleaching, longer lived luminescnece than conventional fluorophores Different emissionwavelengths can be excited simultaneously at a single wavelength in the blue of UV and create a stoke’s shift on the order of nm Coating makes them aqueous soluble as well Wavelength tuning based on size Excitable in UV region FRET applications Multicolour detection Core/shell structure Functionalize surface with species capable of covalently binding DNA, dye

30 Quantum Dot Surface FunctionalizationCdSe/ZnS MAA, chloroform, Hunig’s base Core-shell nanocrystal Shell of a few atomic layers of a higher band-gap semiconductor-improves luminescence quantum yield TOPO-tri-n-octylphospine ligands—coordinate to the Cd centers through the P and P=O to stabilize particle growth and prevent aggregation andprovide someelectronic passivation Ligand exchange with thiol-alkyl-acids (MAA) (MPA) (MUA) where S- strongly coordinates with the Cd2+ or Zn+ EDC, amine terminated dye/DNA

31 QD-FRET-based strategy for two-colour nucleic acid detectionQD-FRET-based strategy for two-colour nucleic acid detection. a) Simultaneous and efficient excitation of green and red quantum dots in the ultraviolet-region without significant excitation of Cy3 or Alexa647 in solution. When probe oligonucleotides were conjugated to QDs, hybridization with a Cy3 or Alexa647 labeled target oligonucleotide yielded FRET sensitized emission from the dyes, which was used as the analytical signal. The green QD-Cy3 FRET pair utilized the SMN1 sequence and the red QD-Alexa647 pair utilized the LacZ sequence. b) A cartoon of the expected emission profiles, where the bracketed regions are of particular analytical interest.

32 Top Ten Nanotechnologies Contributing to Developing WorldHow much difference will the technology make in improving water, agriculture, nutrition, health, energy, and the environment in developing countries? Burden. Will it address the most pressing needs? Appropriateness. Will it be affordable, robust, and adjustable to settings in developing countries, and will it be socially, culturally, and politically acceptable? Feasibility. Can it realistically be developed and deployed in a time frame of ten years? Knowledge gap. Does the technology advance quality of life by creating new knowledge? Indirect benefits. Does it address issues such as capacity building and income generation that have indirect, positive effects on developing countries?

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34 Salamanca-Buentello F, Persad DL, Court EB, Martin DK, Daar AS, et alSalamanca-Buentello F, Persad DL, Court EB, Martin DK, Daar AS, et al. (2005) Nanotechnology and the Developing World. PLoS Med 2(5): e97

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