DNA biosensors

1. DNA biosensors

2. Principles of DNA biosensors
Nucleic acid hybridization
 Perfect match
stable dsDNA, strong hybridization
 One or more base mismatches
weak hybridization

3.  Forms of DNA Biosensors
• Electrodes
• Chips
• Crystals
 Types of DNA Based Biosensors
• Optical
• Electrochemical
• Piezoelectric

4.  simple adsorption
onto carbon surfaces
Immobilization of DNA Probe
onto Transducer Surface

5. Immobilization of DNA Probe
onto Transducer Surface
 Thiolated DNAfor self assembly onto gold (or platinum) transducers

6. Covalent linkage to the gold surface via functional alkanethiol-based
monolayers
Immobilization of DNA Probe
onto Transducer Surface

7. Use of biotinylated DNA for complex formation with a surface-
confined avidin or streptavidin
Immobilization of DNA Probe
onto Transducer Surface

8. Covalent (carbodiimide) coupling to functional groups on carbon
electrodes for carboxyl groups supplying.
Immobilization of DNA Probe
onto Transducer Surfacecarbonelectrodes

9. Immobilization method of DNA probes
on functionalized surfaces.

10. Immobilization method of functional DNA
on functionalized DNA Chip surfaces.