Presentation on theme: "بنام خداوند جان آفرین Nano Particles in Nano-Biotechnology"— Presentation transcript:
1بنام خداوند جان آفرین Nano Particles in Nano-Biotechnology Spring Semester Course (1389)M. Habibi-Rezaei
2What is Nanotechnology Semiconducting metal junction formed by two carbon nanotubesAn engineered DNA strandpRNA tiny motorNanotechnology is the creation of functional materials, devices and systems, through the understanding and control of matter at dimensions in the nanometer scale length (1-100 nm), where new functionalities and properties of matter are observed and harnessed for a broad range of applications
310 millions times smaller What is Nanoscaleww.mathworks.comFullerenes C6022 cm12,756 Km0.7 nm1.27 × 107 m0.22 m0.7 × 10-9 m10 millions times smaller1 billion times smaller
4Nanoscale Size EffectRealization of miniaturized devices and systems while providing more functionalityAttainment of high surface area to volume ratioManifestation of novel phenomena and properties, including changes in:- Physical Properties (e.g. melting point)- Chemical Properties (e.g. reactivity)- Electrical Properties (e.g. conductivity)- Mechanical Properties (e.g. strength)- Optical Properties (e.g. light emission)
5Nanotechnology Applications Information TechnologyEnergyMore efficient and cost effective technologies for energy productionSolar cellsFuel cellsBatteriesBio fuelsSmaller, faster, more energy efficient and powerful computing and other IT-based systemsConsumer GoodsMedicineFoods and beveragesAdvanced packaging materials, sensors, and lab-on-chips for food quality testingAppliances and textilesStain proof, water proof and wrinkle free textilesHousehold and cosmeticsSelf-cleaning and scratch free products, paints, and better cosmeticsCancer treatmentBone treatmentDrug deliveryAppetite controlDrug developmentMedical toolsDiagnostic testsImaging
6Nanoscale Materials Bionanomaterials ProteinBionanomaterialsBiological materials utilized in nanotechnology- Proteins, enzymes, DNA, RNA, peptidesSynthetic nanomaterials utilized in biomedical applications- Polymers, porous silicon, carbonnanotubesCross-linked enzymes used as catalyst – Univ. of Connecticut, Storrs , 2007Enzymes are used as oxidation catalystsBone cell on porous silicon – Univ. of Rochester, 2007Porous silicon (PSi)Human cell on PSi
7Nanoscale MaterialsNanoscale materials have feature size less than 100 nm – utilized in nanoscale structures, devices and systems Nanoparticles and StructuresA 3-dimensional nanostructure grown by controlled nucleation of Silicon-carbide nanowires on Gallium catalyst particles– Univ. of Cambridge, 2007Gold nanoparticles– TU Dresden/ESRF, 2008Silver nanoparticles – Northwestern Univ., 2002A stadium shaped “quantum corral” made by positioning iron atoms on a copper surface – IBM Corp., 1993.
8Nanoparticles Introduction Diesel engines, among others, emit particles consisting of irregularly shaped solid carbon spherules agglomerated in clusters on which some hydrocarbons, sulphates and water condense. Particles are small existing in a sizes ranging from some nanometres to few micrometers.Exhaust particles have gained the attention of research groups due to environmental and health issues. These particles are believed to be harmfull to humans and animals, to moddify the radiative tranfer of the earth and to damage monuments architectural values.
9Nanotechnology in Health Care Thermal ablation of cancer cellsNanoshells have metallic outer layer and silica coreSelectively attracted to cancer shells either through a phenomena called enhanced permeation retention or due to some molecules coated on the shellsThe nanoshells are heated with an external energy source killing the cancer cellsThermal ablation of cancer cells assisted by nanoshells coated with metallic layer and an external energy source – National Cancer Institute
10Nanoscale Processes and Fabrication Top-down ApproachesBottom-up ApproachesOptical and x-ray lithographyLayer-by-layer self assemblyE-beam and ion-beam lithographyMolecular self assemblyScanning probe lithographyDirect assemblyAtomic force microscopic lithographyCoating and growthMaterial removal and deposition(Chemical, mechanical, or ultrasonic)Colloidal aggregationPrinting and imprinting
12Outline Motivation History Colloids Nucleation Growth Coagulation ProcedureViewing the particles
13Motivation Some quacks still assert profound medicinal properties Spherical nanoparticles can serve as biological tags for tracking purposesThe red color in stained glass windows is due to colloidal goldCan be used for a new ultrasensitive and selective detection scheme for DNAGold nanorods can be bar-coded Au/PtOU NanoLab/NSF NUE/Bumm & Johnson
14History Alchemists believed Au sols might be the “elixir of life” Faraday researched many of the properties of colloidal gold in the 1850’s.Mie’s theory of light scattering was developed to explain the color of colloidal gold.Medical applications were developed that diagnosed certain diseases based on the interaction of colloidal gold and spinal fluidsThe first comprehensive investigation using the electron microscope began in 1948 at Princeton University and RCA Labs
15The Optics of Gold and Silver Nanoparticles The color of the sol arises from a combination of absorption and scattering of light and depends on particle sizeMore specifically it is due to a resonance of the free electrons in the metal particle. The light’s electromagnetic field causes them to slosh back and forth (plasmon oscillations).At a characteristic frequency which depends of the size and the metal, the sloshing is the most intense. This is the frequency where plasmon oscillations are excited.The plasmon resonance is easily seen in the extinction spectrum of the sol.OU NanoLab/NSF NUE/Bumm & Johnson
16ColloidsA colloid is a homogeneous dispersion of particles in a solution which are so small as to not settle out easily.A sol is a specific type of colloid characterized as a solid dispersed in a liquid.The colloid is stabilized by electric charges on its surface due to adsorbed ions. The charge causes the particles to repell each other. The both the Gold and Silver sols used here have a negative charge.The particles experience the constant buffeting of Brownian motion which also helps to keep them in suspension.Formulation of Au nanoparticles is a three step process: nucleation, growth, and coagulation
17NucleationNucleation is the creation of nuclei upon which growth can occur.This is a redox reaction: oxidation of the citrate ion produces the necessary reducing reagent for the gold: acetone dicarboxylic acid.The acetone dicarboxylic acid is the limiting reagent for nucleationThe formation of this molecule in the solution creates an induction period before which no product can be seen.The nature of the nucleation curve is evidence of an autocatalytic reaction.That is to say it has a rapid growth after the induction period followed by a linear portion and then decay
18Nucleation (cont.)A type of polymerization (complexation) occurs in which the gold ions coordinate with acetone dicarboxylic acid and join together.When the “polymer,” or complex, reaches a critical mass that is just greater its thermodynamic stability, reduction to metallic gold occurs, yielding the nuclei .Reduction is the rate determining step in the kinetics of the reaction.The less citrate in the mixture, the larger the particles will be in size
19GrowthGrowth is the addition of more gold particles to the existing nuclei.The process of growth stops when all of the gold is used.The rate of growth is a first order in the gold nuclei size.Having the equation dD/dt = kD, where k is a constant whose value is independent of particle size
20CoagulationCreation of the larger gold particles, such as 20 nm, requires a coagulation of multiple (smaller) twins of various shapesA conglomeration of multiple nuclei into particles can be large enough to disturb the stability and fall out of the colloidControl of the coagulation process during preparation determines the size, structure, and size distribution of the particleOnce the preparation of the gold nanoparticles is complete, the absence of coagulation insures its stability
21Procedure Bring to a boil 50 ml of 0.25 mM chlorauric acid solution Add 160 μl to 1.0 ml of 34 mM sodium citrate solution to the boiling solution while stirringAfter a minute will be faint blue and then darkening over 5 min to a brilliant redThe size of the gold nanoparticles can be controlled by varying the amount of sodium citrate solution.The following procedure can grow controlled sizes from 147 nm (0.16 ml) down to 16 nm (1.0 ml).
22Uses of Silver Nanoparticles No more smelly socks - inhibits bacteria that causes foot odour by resisting stains and water absorbance.Antibacterial properties added to athletic wear, bandages (especially burn victims) and cleaning products.Sterilizes water better than chlorine.Curtains embedded with Ag nanoparticles reduce infectious microbes in hospitals.Deactivates HIV by inhibiting the virus from attaching to the host with undetectable levels of cytoxicity.Two brands of sock lost nearly 100% of their silver content within four washings, while two other brands lost less than 1% over the same number of washings.
23Seeing is believing Tunability can make silver nanoparticles with various sizes.each size can absorb light differently.can make them for the visible spectrum.Left to Right10 nm30 nm100 nm
28Relative Size of Nanoparticles Nanoparticle with a 2 nm core and an octanethiol functionalized monolayer
29Making Gold Nanoparticles AuCl4- salts are reduced using NaBH4 in the presence of thiol capping ligandsThe core size of the particles formed can be varied from <1 nm to ~ 8 nmThe surface functionality can be controlled through the choice of thiols
30Fluorophores and Drugs Selectively Dissociate Inside Cells
32Nanotechnology in Health Care TreatmentTargeted drug deliveryNanoparticles containing drugs are coated with targeting agents (e.g. conjugated antibodies)The nanoparticles circulate through the blood vessels and reach the target cellsDrugs are released directly into the targeted cellsTargeted drug delivery – Targeted drug delivery using a multicomponent nanoparticle containing therapeutic as well as biological surface modifying agents – Mauro Ferrari, Univ. of Cal. Berkley
33Nanoscale Devices and Integrated Nanosystems NanochipCurrently available microprocessors use resolutions as small as 32 nmHouses up to a billion transistors in a single chipMEMS based nanochips have future capability of 2 nm cell leading to 1TB memory per chipA MEMS based nanochip– Nanochip Inc., 2006Nanoelectromechanical System (NEMS) SensorsNEMS technology enables creation of ultra small and highly sensitive sensors for various applicationsThe NEMS force sensor shown in the figure is applicable in pathogenic bacteria detectionA NEMS bacteria sensor– Nano Lett., 2006, DOI: /nl060275y
34Nanoscale Devices and Integrated Nanosystems Nanophotonic SystemsNanophotonic systems work with light signals vs. electrical signals in electronic systemsEnable parallel processing that means higher computing capability in a smaller chipEnable realization of optical systems on semiconductor chipA silicon processor featuring on-chip nanophotonic network – IBM Corp., 2008Fuel CellsFuel cells use hydrogen and air as fuels and produce water as by productThe technology uses a nanomaterial membrane to produce electricitySchematic of a fuel cell– Energy solution center Inc.500 W fuel cell – H2economy.com
35Nanoscale Devices and Integrated Nanosystems Lab on ChipA lab on chip integrates one or more laboratory operation on a single chipProvides fast result and easy operationApplications: Biochemical analysis (DNA/protein/cell analysis) and bio-defenseLab on chip gene analysis device – IBN Singapore, 2008Drug Delivery SystemsImpact of nanotechnology on drug delivery systems:Targeted drug deliveryImproved delivery of poorly water soluble drugsCo-delivery of two or more drugsImaging of drug delivery sites using imaging modalitiesTargeted drug delivery– ACS Nano 2009, DOI: /nn900002m
36Nanotechnology in Health Care Nanotechnology offers tools and techniques for more effective detection, diagnosis and treatment of diseasesDetection and DiagnosisLab on chips help detection and diagnosis of diseases more efficientlyNanowire and cantilever lab on chips help in early detection of cancer biomarkersThe microfluidic channel with nanowire sensor can detect the presence of altered genes associated with cancer – J. Heath, Cali. Insti. of TechnologyThe nanoscale cantilever detects the presence and concentration of various molecular expressions of a cancer cell – A. Majumdar, Univ. of Cal. at Berkeley
37Nanotechnology Health and Environmental Concerns Human and the environment come under exposure to nanomaterials at different stages of the product cycleNanomaterials have large surface to volume ratio and novel physical as well as chemical properties which may cause them to pose hazards to humans and the environmentHealth and the environmental impacts associated with the exposure to many of the engineered nanomaterials are still uncertainThe environmental fate and associated risk of waste nanomaterials should be assessed – e.g. toxic transformation, and interactions with organic and inorganic materialsExposure of human and the environment to nanomaterials at different stages of product life cycle – US environmental protection agency, 2007 (epc.gov)