Macromolecular Adsorption


Introduction:

With support from the Polymer MRSEC at the University of Massachusetts, we have been engaged in studies of the adsorption of macromolecules (polymers and molecules of biological interest) onto surfaces by means of the techniques of surface plasmon rsonance (SPR).

These studies have recently been directed at the adsorption of a positively charged polyelectrolyte [6-6] ionene bromide onto a self assembled monolayer surface of selectable charge density comprised of undecanethiol (UDT) and mercapto-undecanoic acid (MUA). We find that there is a threshold for enhanced dadsorption when the positive charge spacing on the polyelectrolyte matches the average (negative) charge spacing in the self assembled monolayer[1].

Earlier studies have involved the kintics of adsorption of RABSA to substrates previously decorated with BSA [2-4]. We are also engaged in attempts to image structures adsorbed to the substrates. The goal is to observe orientational phase transitions on the substrates.

Future directions are expected to involve imaging of orientational transitions of macromolecules at surfaces, adsorption of polyelectrolytes onto surfaces with patterned charge distributions, and studies of molecular rearrangements at membrane surfaces.


References:

[1] J.R. Rahn and R.B. Hallock, submitted to Macromolecules.
[2] C.S. Mayo and R.B. Hallock, J. Immuno. Meth. 120, 105 (1989).
[3] C.S. Mayo and R.B. Hallock, Rev. Sci. Instrum. 60, 739 (1989).
[4] J.R. Rahn and R.B. Hallock , Langmuir 11, 650 (1995).