Raman Spectroscopy and some experimental results - PowerPoint Presentation

Slide1

Raman Spectroscopy and some experimental results

ProfessorDr. HANS SCHUESSLER

By

Ansam Jameel Talib

Molecular Physics Course

Slide2

History of Raman Scattering1923

– Inelastic light scattering predicted by A. Smekel1928 – Landsberg and Mandelstam saw unexpected frequency shifts in scattering from quartz

1928

– C.V. Raman and K.S. Krishnan saw “feeble fluorescence” from neat solvents 1930 – C.V. Raman wins Nobel Prizehttp://www.aps.org/publications/apsnews/200902/physicshistory.cfm

C. V. Raman

http://bwtek.com/raman-theory-of-raman-scattering/Slide3

Raman Spectroscopya spectroscopic technique used to observe vibrational, rotational, and other low-frequency modes in a system.

Raman spectra are similar to infrared spectra .

Useful

for functional group detection and fingerprint regions that permit the identification of specific compounds.

The advantages:

small sample requirement, minimal sensitivity toward interference by water, and high conformational and environmental sensitivity.http://www.inphotonics.com/raman.htmSlide4

Can Raman spectra be obtained from solids, liquids and gasesSolids LiquidsGels

Slurriespowders films, etc. Raman spectra can even be obtained from some metals.

It is possible to obtain Raman spectra of gases.

However, since the concentration of molecules in gases is generally very low, this typically requires special equipment, such as long

pathlength

cells.https://depts.washington.edu/ntuf/facility/docs/NTUF-Raman-Tutorial.pdfSlide5

Types of Raman Spectroscopy

1- Surface-enhanced Raman spectroscopy (SERS)2- Resonance Raman spectroscopy 3- Angle-resolved Raman spectroscopy 4- Hyper Raman5- Spontaneous Raman spectroscopy (SRS)6- Optical tweezers Raman spectroscopy (OTRS) 7- Stimulated Raman spectroscopy8- Spatially offset Raman spectroscopy (SORS)

9- Coherent anti-Stokes Raman spectroscopy (CARS)

10- Raman optical activity (ROA)

11. Transmission Raman 12. Inverse Raman spectroscopy13- Tip-enhanced Raman spectroscopy (TERS)14- Surface plasmon polariton enhanced Raman scattering (SPPERS) 15- Stand-off Remote Raman 16- Confocal Ramanhttp://en.wikipedia.org/wiki/Raman_spectroscopySlide6

Tip-enhanced Raman spectroscopy (TERS)Tip-Enhanced Raman (TERS or

nanoRaman): chemical imaging at the nanoscaleTERS (or nano-Raman) brings you the best of both worlds: the chemical specificity of Raman spectroscopy with imaging at spatial resolution typically down to 10nm. This technique can be demonstrated on various samples ranging from nanotubes to DNA. TERS has been shown to have sensitivity down to the single molecule level and holds some promise for bioanalysis applications

http

://www.intechopen.com/books/electronic-properties-of-carbon-nanotubes/detection-of-carbon-nanotubes-using-tip-enhanced-raman-spectroscopy

http://www.intechopen.com/books/electronic-properties-of-carbon-nanotubes/detection-of-carbon-nanotubes-using-tip-enhanced-raman-spectroscopy

http://www.asdn.net/asdn/nanotools/spm.shtmlSlide7

Confocal Raman

Couples a Raman spectrometer to a standard optical microscope, allowing high magnification visualization of a sample and Raman analysis with a microscopic laser spot.  Raman microscopy is easy: simply place the sample under the microscope, focus, and make a measurement. Just adding a microscope to a Raman spectrometer does not give a controlled sampling volume - for this a spatial filter is required.  Confocal Raman microscopy refers to the ability to spatially filter the analysis volume of the sample, in the XY (lateral) and Z (depth) axes.

http://www.horiba.com/us/en/scientific/products/raman-spectroscopy/raman-academy/raman-faqs/what-is-confocal-raman-microscopy/Slide8

Confocal Principle

Laser (

λ

nm): power (

mW

)

405 nm : 0.65

mW

532 nm : 10.5

mW

660 nm : 12.3

mW

785 nm: 35.5

mW

The

LabRAM

HR Evaluation is an integrated Raman system. The microscope is coupled to a 800 mm focal length spectrograph equipped with two switchable gratings

.

http://

www.horiba.comSlide9

Ansam J. Talib1

, Sandra C. Bustamante1 , Zachary N. Liege 1,2

, Sarah Ritter

1

, Alexander Sinyukov1

, Dmitri V. Voronine1,2, Alexei V. Sokolov1,2,

Kenith Meissner

1

and

Marlan

O. Scully

1,2,3

1

Texas A&M University,

2

Baylor University,

3

Princeton University

Raman

Spectroscopy

and Imaging of Red Blood CellsSlide10

MotivationsToday, more than 340 million people

suffer from diabetes and this number doubles every 15 years.*

In the USA, 30 million people have diabetes and 87 million more have pre-diabetes.

Common diabetic monitoring procedures include

checking blood sugar levels multiple times a day by finger pricks using

a glucose meter or an implantable glucose biosensor.**

*Danani

G, Finucane

MM, et al. National,

regional,and

global trends in fasting plasma

gluocose

and diabetes prevalence since 1980: systematic analysis of health examination surveys and epidemiological studies with 370 country- years and 2.7 million participants. The Lancet 2011; 378:31-40.

**

Vashist

SK. Non-invasive glucose monitoring

technologyin

diabetes management: A review. Anal

Chim

Acta

2012;750:16-27.

http://

www.medicalmalpracticeinquirer.com/assets_c/2011/01/iStock_000004641088Large-thumb-300x200-6230.jpgSlide11

Goals of the projectOur long-term goal is to develop red blood cells (erythrocytes) loaded with a fluorescent dye (

erythrosensors), which can be detected with a light source through the skin and can be used as biocompatible glucose bio-sensors (because such cells will stay in circulation instead of triggering an immune response, and getting out of circulation

).

The specific aim is to measure

the difference between FITC-ghost glygly and normal red blood cells.Slide12

Red blood cells (RBCs)RBCs (also called erythrocytes) are the most common type of blood cells

and are the vertebrate organism's principal means of delivering oxygen to body tissues.RBCs are the most abundant cells in blood, with a shape of a biconcave disk with a flattened center (look like donuts).

RBCs

contain a special protein called

hemoglobin, which helps carrying oxygen.http://bio662.dyndns.info/s3b/b3n/b3n02BloodCirculation/b3n02eBldC112BloodCells.htmSlide13

Cell MembranesRBC membrane plays many roles that aid in regulating their surface deformability, flexibility, adhesion to other cells and immune

recognition.They can be squeezed to 3 microns.

Membranes of RBC

100x Slide14

Fluorescein isothiocyanate (FITC)

Fluorescein (mistakenly abbreviated by its commonly-used reactive isothiocyanate form, FITC) is a small organic molecule, and is typically conjugated to proteins via primary amines. Usually, between 3 and 6 FITC molecules are conjugated to each antibody

In cellular biology, FITC is often used to label and track cells

Excitation: max = 495 nm

Emission: max = 525

nm http://www.sigmaaldrich.com/content/dam/sigmaaldrich/docs/Sigma/Product_Information_Sheet/f7250pis.pdfSlide15

RBC

Membranes

of RBC

FITC ghost Slide16

Raman Spectrum of Hemoglobin

Laser 532 nm

Slit 200

Grating 600 gr/mm

Objective 50xSlide17

Optical image and Raman spectrum of RBC

Laser 532 nm

Slit 200

Grating 600 gr/mm

Objective 50

xObjective 50xSlide18

Raman Images of RBC

Bimolecular class: Unknown

Trp

: tryptophan

C-N stretch

Cytochrome- like moiety

(resonance enhanced)

Protein

Slide19

Raman Spectrum of FITC Ghost Cells

Laser 532 nm

Slit 200

Grating 600 gr/mm

Objective 50xSlide20

Optical and Raman Images of FITC Ghost Cells

Laser 532 nm

Slit 200

Grating 600 gr/mm

Objective 50xSlide21

RBC Slide22

ConclusionsConfocal microscopy will allow us to investigate the vesicle size and shape of RBCs and FITC ghost.We can get a clear understanding for the distribution of the hemoglobin inside the RBCs and the FITC-ghost.

TERS of RBCsSlide23

Thanks For Your ATTENTION !!!!