This last approach is most attractive since quantum dots offer
significant advantages over conventional fluorescent dyes since
they are brighter, more photostable materials with narrow
emission bands that can be excited by any wavelength greater
than the energy of their lowest transition.7 These properties also
allow optical barcoding6 of polymer supports by combining
different colour quantum dots with different intensity levels.
However, the approach described to generate the quantum dot
encoded materials simply involved embedding the quantum
dots into the outer layers of 1–2 mm resin beads then sealing
with a final silica layer. Whilst encoded materials of this type
appear to be ideal for the optical encoding of biomolecules6 the
method of quantum dots immobilisation is non-covalent in
nature and thus materials generated in this manner would not be
suitable for widespread application in solid phase organic
synthesis. We thus elected to establish the feasibility of
incorporating quantum dots covalently into the polymer
matrices of supports of the type used routinely in the solid phase
synthesis of combinatorial libraries.