Table 1: Surface elemental concentration (in At.%) of C, O, Si, and N, as determined by XPS on aminated glass and PEG-modified surfaces using various star PEG coupling concentrations.

SurfaceO%C%Si%N%

Aminated glass40.936.617.04.8
0.55% PEG 38.344.512.73.7
1.66% PEG 37.446.811.83.3
5% PEG 36.150.310.13.1
15% PEG 37.448.111.12.8