Luminescent sensors and photonic switches*
A. Prasanna de Silva**, David B. Fox, Thomas S. Moody, and Sheenagh
M. Weir
School of Chemistry, Queen's University, Belfast BT9
5AG, Northern Ireland
Abstract: The principles of photochemistry continue to fuel
progress in luminescent sensors and photonic switches. Examples of sensors
based on photoinduced electron transfer (PET) are discussed, including
those which form the basis of successful systems used in physiology
and medicine. More complex formats usually involve multiple receptors.
One progression takes us to lanthanide complexes enabled with sensory
capabilities. Another path takes us to molecular-scale implementation
of logic gates such as AND and INHIBIT. Such luminescent switches can
be enriched by combination with nonluminescent cousins. The latter are
based on internal charge-transfer excited states (ICT). An example of
rudimentary arithmetic at the molecular scale is presented by running
a luminescent AND gate in parallel with a nonluminescent XOR gate. Thus,
small molecules can process small numbers for the first time outside
of our brains.
*Lecture presented at the XVIIIth IUPAC Symposium on
Photochemistry, Dresden, German , 22-27 July 2000.Other presentations
are published in this issue, pp.395-548.
**Corresponding author
