Surface patterning and fuctionalization of Nanoparticals

1. NANOBIOTECHNOLLOGY
Presentation topic: Surface patterning and functionalization
Presented by :Laiba Tariq
Roll No:5812
Bs chemistry 8th semester

2. FUNCTIONALIZATION AND SURFACE
PATTERNING
Contents
Functionalization
➢Introduction
➢Chemistry of functionalization
➢ Applictaions
➢Limitations
Surface patterning
➢Introduction
➢Techniques
➢Example

3. FUNCTIONALIZATION
Introduction:
• Functionalization is the introduction of organic molecules or polymers on the
surface of NPs.
• “To improve the properties of NPs and to make them biocompatible, it is necessary to
physically or chemically attach certain molecules or FGs to their surfaces this process
is called functionalization.”

4. CONTINUE……
• Surface coating of NPS
determine many of their
physical and chemical
properties, notably stability,
solubility and targeting.
• A coating that is multivalent
or polymeric confers high
stability.

5. WHY FUNCTIONALIZATION?
• There are limitations in the application of Nps.
• Surface modification help to tune their properties to suit different
applications.
• Surface modification can be used to prevent aggregation,improve
stability in suspension and enhace the compatibility of NPs with solid
matrices or biological environment

6. CHEMISTRY OF FUNCTIONALIZATION
• Non covalent binding:
Non covalent interection is based on van der waal forces. Great advantage of this type
of functionalization relies upon the possibility of attaching various groups without
disturbing π electronic cloud of substrate.

7. CHEMISTRY OF FUNCTIONALIZATION
• Covalent Binding:
Functionalization is also possible by direct binding of molecule of interest to the
reactive ligands on NP surface, facilitated by covalent conjugation.
• Amorphous Nanoparticle Coating:
Inorganic NPs like metal NPs have to be coated with silica or some other polymers
which can introduce functional groups to them. Surface coating also imparts
additional functionality to the NP as it allows targeting ligand/therapeutic
attachment.

8. MAGNETIC NP:
• The coating of the magnetic
cores is crucial for protection
against oxidation and
particle aggregation.
Applications:
• Such functionalized
magnetic NPs are used in
pre- or post-treatment
sequences in wastewater
remediation, the
degradation efficiency of
micropollutants can be
greatly improved by this
way.

9. GOLD NP:
• Gold nanoparticles (GNPs)
have been extensively
studied for many
applications due to their
unique electrical, chemical,
and optical properties.
Applications
• Functionalization facilitates
targeted delivery of these
nanoparticles to various cell
types, bioimaging, gene
delivery, drug delivery and
other therapeutic and
diagnostic applications.

10. SILICA NP
• A variety of surface
modifications to enhance
biocompatibility have been
employed often involving the
chemical attachment with
different molecules.
Application:
• They have been intensively
investigated for drug
delivery applications

11. LIMITATIONS OF FUNCTIONALIZATION:
• Yield is very low which would require very large setup to
commercialize the product.
• Functionalization involves a lot of repeated processing of the NPs
which further decreases the yield as in every chemical process we tend
to lose the particles.
• Require laser irradiation or other complex covalent bonding
techniques.

12. SURFACE PATTERNING
Controlling the nature and
properties of surfaces is essential to
position nanoparticles with desired
geometries and dimensions. The
surface properties of surfaces can
also be altered by patterning of
self-assembled monolayers.

13. TECHNIQUES USED FOR SURFACE
PATTERNING:
• Photolithograpy
• Electron beam lithography
• Ion beam lithography
• Dip pen nanolithography,
• Microcontact chemistry (μCC)

14. EXAMPLE: PATTERNING OF AU NPS ON
HYDROGEL
Step 1: Deposition of Au NPs on Silicon Wafers
Gold nanoparticles were synthesized by using sodium citrate and they were
deposited on silicon wafer by Immersion and by solvent evaporation methods.
Step2: Transfer of Au NPs on PEG hydrogel

15. Step 3: Transferring patterns of Au NPs on Si Wafer
Step 4: Transfer of pattern on Hrdrogel