Quantum dot particles (Qdots)
Qdots are three-dimensionally constrained, stable, water-soluble nanostructures, made from crystals of semiconductor material such as cadmium selenide encased in a zinc sulphide shell. The particles are nanoscopic in size and have been likened to �molecular LEDs�.
Key features of Qdots:
1) can be attached directly to biological materials
2) potential of tuneable fluorophores rather than fixed wavelength emission of conventional dyes
3) enhanced sensitivity due to photostability
4) potential for multiplexing and high throughput screening
A practical application for Qdots is the creation of microscopic barcodes. Polymeric microbeads are impregnated with quantum dots. When attached to DNA probes or to antibodies, a bead can bind to a target molecule, thereby tagging it and allowing the multiplex coding of biomolecules.
(Click 
for a schematic representation of Qdot microbeads).
For more information visit the web site of the Quantum Dot Corporation : (http://www.qdots.com)
Smart probes
Smart probes represent a development of hairpin oligonucleotide-based probe technologies. They are similar to Molecular Beacons, except that complementary guanosine residues are used to quench the fluorophore moiety.
(Click for a diagram of the process)
As in the case of Molecular Beacons, the probe possesses a stem loop structure, whereby the loop is complementary with the target sequence and the stem is formed by annealing two complementary arm sequences together. However, these new probes are only labelled at one end with a fluorescent dye, oxazine dye JA242. A key feature of this type of probe is that unlabelled probes do not contribute to the measured signal, thereby, making this probe format suitable for single molecule detection assays.
Atto-Tec GmbH is currently marketing this technology as �GenePin� probes (http://www.atto-tec.com/).
For more information on these and other novel technologies visit the UK Bio-measurement network and down load the following report from the Document Library:
'Survey on emerging technologies potential for highly sensitive detection.'