In another development, Goddard et al. (Barish &
Goddard, 2011; Tian, Decker, & Goddard, 2012) modified
the surface of LDPE by grafting a biocompatible polymer
(polyethylene glycol, PEG) to its ozone-treated surface.
The resulting surface was then functionalized with a range
of amine-terminated bioactive molecules. Ethylenediamine
or polyethyleneimine was covalently attached to the PEGgrafted
film and the metal chelator poly(acrylic acid)
(PAA) was attached to the amines to increase the number
of available carboxylic acids. The final material showed
to have a higher affinity to Fe3þ than Fe2þ with the optimum
binding pH at 5.0.