Table 1.
XPS results for LKα14 adsorption onto methyl SAMs. The C, O, N, and S atomic percents were renormalized to 100 atomic % to show the composition of the organic overlayer (SAM plus peptide). The Au atomic % before renormalization and the N/Au ratio show the attenuation of the gold signal by the organic overlayer.
| Peptide Adsorption Concentration (mg/mL) | C atomic %* | O atomic %* | N atomic %* | S atomic %* | Au atomic % | N/Au ratio |
|---|---|---|---|---|---|---|
| 0.1 | 78.9 (2.3) | 15.1 (0.9) | 4.1 (0.4) | 1.9 (0.1) | 48.3 (1.4) | 0.043 (0.005) |
| 0.2 | 83.0 (10.4) | 10.3 (3.6) | 3.8 (1.5) | 2.1 (0.4) | 45.6 (5.3) | 0.050 (0.024) |
| 0.3 | 78.5 (10.2) | 12.2 (2.4) | 7.0 (2.1) | 1.6 (0.3) | 35.7 (7.3) | 0.14 (0.07) |
| 0.4 | 77.3 (2.7) | 12.6 (2.6) | 8.2 (1.7) | 1.4 (0.3) | 26.9 (3.9) | 0.23 (0.08) |
| 0.5 | 75.1 (7.3) | 14.4 (1.6) | 8.5 (1.6) | 1.4 (0.3) | 29.3 (6.7) | 0.22 (0.08) |
| 1 | 74.1 (3.7) | 14.7 (1.0) | 9.6 (0.7) | 1.1 (0.2) | 21.1 (3.4) | 0.37 (0.07) |
| Calculated Values for Monolayer | 83.1 | 6.5 | 8.4 | 2.0 | 34.3 | 0.16 |
| Calculated Values for Bilayer | 78.3 | 8.9 | 11.6 | 1.1 | 22.6 | 0.40 |
*
Renormalized to 100% without the Au signal.