Advances in Fingerprint Technology.pdf

Figure 6.19 Photoluminescence of fingerprint (on aluminum foil) developed by
diimide-mediated CdS/generation 3.5 dendrimer treatment (see text).
10 –2 M diimide to 2.4 × 10 –4 M dendrimer) was intended to minimize the
formation of ester in the fingerprint residue itself upon subsequent sample
immersion. The ester formed would tie up the amino acid of the fingerprint
that otherwise would react with dendrimer. The heating step was essential.
Without it, fingerprint development was only faint. The diimide reacts with
aluminum foil to give it a tarnished appearance, much like tarnished silver.
Without the heating step, this tarnishing resulted upon immersion of aluminum
foil samples. One can thus presume that the counterproductive reaction
with fatty acid of the fingerprint residue also occurs. With heating, on the
other hand, no foil tarnishing was seen, indicating that the diimide had been
tied up by the dendrimer, as desired. Formation of the CdS/dendrimer nanocomposite
followed by diimide addition (prior to fingerprint sample immersion)
was not successful, perhaps because of excessive aggregation prior to
the addition of the diimide. Although the above-described fingerprint labeling
by dendrimer, as mediated by carbodiimide, has only been explored for
feasibility to date, rather than having reached the practical recipe stage, a
reasonable grasp of the underlying chemistry has hopefully emerged.
Incorporation of Lanthanide Complexes into Dendrimers 21
Because dendrimers have many voids (of varying sizes), one can envision
intercalation of molecules in the dendrimer (i.e., their placement into voids