1. The presentation discusses using UV-Visible spectroscopy to analyze various nanomaterials and nanoparticles. 2. UV-Visible spectroscopy can be used to determine the formation and reduction of graphene oxide as well as monitor the formation of nanocomposites with changes in absorbance peaks. 3. The technique is also applied to study the effects of nanoparticle size, shape, aggregation state, and ligand binding on localized surface plasmon resonance peaks.

2. Presentation Topic:
Muhammad Aadil
PhD research Scholar
Session (2017-2020)
DEPARTMENT OF CHEMISTRY
The Islamia University of Bahawalpur
UV-Visible Spectroscopy

3. What is Spectroscopy?
Source
Matter
EMR
Absorbance
Transmittance
Excited Fluorescence
Scattering
Reflection
UV Spectroscopy: Techniques, instrumentation and data handling
by B.J. Clark, T. Frost, M.A. Russell

4. Conformation of Formation of rGO from GO
Green synthesis of graphene and its cytotoxic effects in human breast cancer cells by Sangiliyandi Gurunathan
Jae Woong Han,Vasuki Eppakayala and Jin-Hoi Kim
The π-π* transition in GO
give λmax at 230nm. The
Reduction of GO to rGO
cause restoration of C=C
conjugation structure so
λmax shifting to 265nm.
Application of UV-Visible in Nanoscience

5. Spectroscopic investigation on graphe ne-copper nanocomposites with strong UV emission and highcatalytic activity
Formation of Nanocomposite
with Cu nanoparticles cause
hypochromic effect and
Hypsochromic effect.
Composite Formation

6. UV/VIS/IR SPECTROSCOPY ANALYSIS OF NANOPARTICLES
Aggregation of GNPs results red-shift in the spectrum, as
well as broadening of adsorption peaks, and decrease in
peak intensities. Aggregation states can visibly detected
by a change in color of the solution from red to blue/purple

7. To Check Stability of Nanopartilces

8. Gold nanoparticles size dependant surface Plasmon resonance
Localized surface Plasmon resonance (LSPR), that is, the collective
oscillation of electrons in the conduction band of gold nanoparticles in
resonance with a specific wavelength (500nm-600nm) of incident light.

9. Binding of Ligand to the nanoparticles surface
Binding of ligands to GNPs, shift the LSPR spectrum toward red region. This shift
is a result of an increase in the local refractive index at the gold nanopartilces
surface due to points of "unevenness" at the particle surface.

10. Gold nanoparticles shape dependant surface Plasmon resonance
The peak absorbance wavelength increases with particle diameter, and for
uneven shaped particles such as gold nanourchins, the absorbance spectrum
shifts significantly into the far-red region of the spectrum when compared to a
spherical particle of the same diameter.

11. Gold nanoparticles shape dependant surface
Plasmon resonance
If the particles would not be spherical then absorption
band would appear at longer wavelengths while it
gradually shift to shorter wavelengths as the particles
become more spherical.
(Chakraborty, 1998; Baia et al., 2006).

12. Verification of full reduction
The electronic transitions involving the Ag+ ion give rise
to absorption bands located between 200 and 230 nm,
whereas the electronic transitions of metallic Ag○ appear in
the 400-500 nm spectral range.
( )
Reduction of Silver Ions by Cell Free Extracts of Westiellopsis sp.Lakshmi PT, Priyanka D, Annamalai A - Int J Biomater
(2015