Ppt

3. Surface Plasmon Resonance
• Surface Plasmon are special
electromagnetic waves that can be
excited on the metal surface ( eg:
(Gold or Silver)
• These plasmons are generated at
the boundary of metal and extrenal
medium
• They propogate parallel to the
metal or dielectric surface.
• Plasmons are very sensitive to any
changes in boundary ( eg:
Adsorption of biomolecules to
metal surface.

4. Surface Plasmon Resonance
• They provide Label free, real time detection Of various bimolecular
reactions.
• Determine kinetics of the binding reactions
• Signals are Recorded in the form of sensogram
• It measures change in the refractive index of medium Directly in
contact with the surface.

5. PRINCIPLE
• The surface is typically a thin gold film on the glass
support.
• This forms the floor through which aqueous solution is
passed continuously
• Receptor molecules are immobilized on the sensor
surface.
• Analyte molecules are injected in the aqueous solution
through flow cell
• Polarised light is passes from lazer source which js
directed through prism .
• Surface plasmons are generated at critical angle of
incident light .
• During interaction between the immobilized receptor
and analyte molecule occours. Refractive index at the
gold film changes
• Change in refractive index is observed as increase in
intensity of signal ( measured in RU (resonance unit))

6. BIOCORE SYSTEM
• Biocore systsm utilises the natural
phenomenon of SPR measurement and
provides information in number of
application.
• Different types of chips are inserted in the
biocore system
• The SPR consist of 3 parts
1. Optical system( includes the light source)
2. Sensor system(Transform the sensitive
information to change in refractive index
of film)
3. Detection system( detect the intensity of
reflectes light)

7. Immobilization of
Ligands or receptors
• IMMOBILIZATION ON CM5 SENSOR
CHIPS
Immobilisation on Ni- NTA chips
• Surface has carboxymethylated dextran matrix
Which js preimmoblised with NTA ( nitroacetic
acid)
• Activate chips by passing nickle sulphate solution
on sensor chip NTA
• This is designed to bind histidine tagged
biomolecules to check interaction .
AMINE COUPLING
THIOL COUPLING
• ECD AND NHS are
used as reagents
• Protein ligand is
immobilized by linking
amine function group
on surface through an
amide linkage
• To remove non specific
binding ethanol is used
• Immobilisation of
ligand containing free
thiol group is done by
formation of disulfide
bond with sulfur matrix
on sensor chip
• Eg: