IN THIS SECTION
Optical Biosensors & Biophotonics
Quantum dot switches for biomolecular sensing
Semiconductor quantum dots, such as ZnS-capped CdSe nanocrystals, are extremely attractive fluorescent probes for biosensing applications possessing: very high fluorescence yields, extinction coefficients several times higher than convention organic fluorophores, low photobleaching, but most importantly narrow, symmetric emission peaks (approx 25-35nm, full width at half maximum) which can be tuned as a function of the particle size. We have recently demonstrated that the emission of CdSe quantum dots linked to the 5’-end of a DNA sequence is efficiently quenched by hybridisation with a complementary DNA strand with a gold nanoparticle attached at the 3’-end; contact of the quantum dot and gold nanoparticle occurs.
Present activities include exploitation of the patterned surfaces for
- Biomolecular sensing of low copy numbers of DNA in integrated devices, (in collaboration with Prof. Tom Brown from Chemistry)
- Self-assembly strategies for nanophotonic/electronic devices (in collaboration with Prof. Jeremy Baumberg from Physics)
Copyright University of Southampton 2006