Thyroxine capped silver nanoparticles were synthesized using a one-step photochemical method. Characterization showed the nanoparticles were spherical, ranging from 12-16 nm in size, with a surface plasmon resonance peak at 418 nm. Fourier transform infrared spectroscopy indicated the thyroxine involved amine and hydroxyl groups in reducing silver nitrate. The nanoparticles were stable for 20 days at temperatures from 4-50°C.

1. Photochemistry Mediated Synthesis and
Characterization of Thyroxine Capped
Silver Nanoparticles
Submitted by
R.Priyanka
M.Sc Biotechnology
Department of Biotechnology
University of Madras

2. INTRODUCTION
• Nanotechnology is the branch of science, technology and
engineering that deals with the study of imaging, measuring,
modeling and manipulating of single molecules in nanometer
scale

3. NANOPARTICLES
• The term “nano” is derived from Greek word “nanos” which
means extremely small
• It deals with matter of size 1 billionth meter or 10-9 m
• Nanoparticle size ranges from 1 to 100nm

4. Types of Nanoparticles
Metal Nanoparticles
• Silver Nanoparticles
• Gold
• Magnetic Nanoparticles
• Silica
• Zinc oxide
• Titanium dioxide
• Copper
Polymer Nanoparticles
• Chitosan
• Fibrin etc…

5. Methods of Nanoparticles Synthesis
• Methods for nanoparticles synthesis includes Top-Down method and
Bottom-Up method
• Top-Down method includes formation of nanoparticles from bulk material
by grinding or milling
• Bottom-Up method includes the atom arrangement to generate
nanostructures
• These methods can be achieved by using physical, chemical and
biological.

6. Application of Nanoparticles
• Bioimaging
• Sensing
• Catalysis
• Cancer treatment
• Drug delivery
• Cosmetics
• Biomedical…etc

7. Silver nanoparticles
• Silver nanoparticles (AgNPs) are one of the noble metal nanoparticles
studied due to their amenability of synthesis, functionalization and ease of
detection
• AgNPs have unique optical, electrical, and thermal properties
• Exhibit high plasmon efficiency
• More sensitive towards localized surface plasmon resonance
• Less time consuming, economic and more ecofriendly
• It is used in electronics, food industry, cosmetics, photochemical,
biomedicine and chemistry.

8. Thyroxine
• Thyroxine is a hormone which is naturally secreted in our body by thyroid gland
• Normal range of T4 hormone is 4.5 to 12 µg/dl.
• Deficiency of thyroxine is managed by oral administration of thyroxin drugs
• In this study we have synthesized AgNPs using commercially available thyroxine, which act
as reducing and capping agent

9. Objective
 Synthesis of silver nanoparticles using thyroxine as a reducing and capping agent
through the one step photochemical method
 Characterization of synthesized silver nanoparticles (Thy-AgNPs)
1. UV-Spectroscopy Analysis
2. Fourier Transforms-Infra Red Spectroscopy (FT-IR)
3. High Resolution Transmission Electron Microscopy(HR-TEM)
4. Field Emission Scanning Electron Microscopy(FE-SEM)
5. Dynamic Light Scattering (DLS)
6. Zeta potential

10. Synthesis of silver nanoparticles (AgNPs)
• 20 ml of silver nitrate (1mM) was taken and 800µl of 24 µM Thyroxine
(concentration 18.75 µg/ml, pH:7) was added and mixed well , placed it in
sunlight .
• After 15 minutes, the colorless solution was changed to yellow color that indicates
the synthesis of AgNPs.

11. Characterization-UV Spectroscopy
The synthesized AgNPs was primarily subjected to UV
Spectroscopy analysis and the corresponding SPR was 418 nm,
which confirmed the AgNPs formation

12. Standardization of AgNPs synthesis
Standardization of AgNPs synthesis using different concentration of Thyroxine
AgNPs synthesis were standardized using different concentration of Thyroxine namely 75µg/ml (96µM),
37.5µg/ml (48µM), 18.75µg/ml (24µM), 9.37µg/ml (12µM). The corresponding SPR recorded, among that
18.75µg/ml concentration of thyroxine gave better synthesis of AgNPS (418nm), remaining concentration gave
broad SPR peak

13. Standardization of AgNPs synthesis
Standardization of AgNPs synthesis using different pH of Thyroxine
AgNPs synthesis were standardized using different pH of Thyroxine (pH: 7,8,9,10)
and corresponding SPR recorded, among that pH 7 of thyroxine gave better
synthesis of AgNPS , remaining gave broad SPR peak

14. Stability analysis of AgNPs at different temperature
Stability of AgNPs were analyzed at different temperature (4°C, RT, 40°C, 50°C) for
6 hours after that corresponding SPR were recorded and the synthesized AgNPs were
very stable at all above temperatures (4 °C to 50°C)

15. Stability analysis of AgNPs
• Stability of AgNPs were analyzed at different duration (0,10,
20 days) and corresponding SPR were recorded and the
synthesized AgNPs were very stable at all above durations

16. Fourier Transforms-Infra Red Spectroscopy (FT-IR)
Here the peak of synthesized Thyroxine capped Silver
nanoparticles shows Amine group and hydroxyl group are
involved in the reduction of silver nitrate solution.

17. a) FE-SEM analysis of AgNPs b) EDX analysis of AgNPs
The synthesized silver nanoparticles was coated on the aluminum foil then allowed to dry
and subjected to FE-SEM analysis. The synthesized AgNPs was spherical shape
It was further subjected to EDX analysis that confirms the presence of AgNPs
Field Emission Scanning Electron Microscope (FE-SEM)

18. AgNPs solution was placed on the copper grid and allowed to dry in room
temperature for 2 hours. The grid was then examined under the HR-TEM
analysis. The synthesized nanoparticles were spherical shaped and size ranging
from 12 to 16 nm
HR-TEM Analysis of AgNPs
HR-TEM and SAED pattern of AgNPs

19. Dynamic Light Scattering (DLS)Analysis
AgNPs solution was diluted with double distilled water and
examined under the zeta sizer and different size (d.nm) of the
nanoparticles were measured. The size ranges from 10 to 90 nm,
and the average size of AgNPs was 32.67 d.nm.

20. -potential
• AgNPs solution was diluted with double distilled water and examined
under the zeta sizer for measurements of net charge of the nanoparticles,
the synthesised AgNPs net charge was -9.40mV.

21. Conclusion
• Novel thyroxine capped silver nanoparticles was
successfully synthesized in cost effective one step
photochemical method
• The stability of synthesized AgNPs were analyzed in
different temperatures and time duration
• Characterization of nanoparticles that includes size,
shape, average diameter size, net charge, functional
group analysis also carried out.

22. Future studies
• Bioimaging
•Antibacterial activity against potential human pathogenic
bacteria and fungi
• Sensing application in biological and environmental systems