Table 1:
Rest potentials measured vs an Ag/AgCl reference with a 3M KCl bridge, converted to NHE by adding 210 mV.
| Description | Pt (mV vs NHE) | Pd(mV vs NHE) | Au(mV vs NHE) | |
|---|---|---|---|---|
| UHV1 | Plasma-cleaned films in UHV | 435±1251 | 395±125 | 695±125 |
| Bare chip 1 mM PB | Films under 1 mM phosphate buffer | 566.8±3.82 | 540.7±17 | 388.4±4.3 |
| Chip/SH-btn | Functionalized with thiolated biotin | 585.3±0.2 | 482.3±0.1 | 242.5±0.7 |
| Chip/SH-btn/SA | As above bound by streptavidin | 578.9±0.4 | 460.5±1.9 | 236.8±0.6 |
| Chip/SH-btn/SA/ϕ29 | As above bound by a doubly-biotinylated ϕ29 polymerase | 564.4±2.8 | 393.4±0.2 | 199.8±2.8 |
| Bare chip (repeat) | Films under 1 mM phosphate buffer | 567.6±3.3 | 558.5±1.8 | 417.2±1.8 |
| Chip/SH-DNP | Functionalized with thiolated DNP | 534.0±4.1 | 508.3±0.7 | 266.4±1.0 |
| Chip/SH-DNP/Ab | As above + anti-DNP IgE | 537.8±0.7 | 438.1±0.3 | 256.1±0.2 |
1
UHV data were measured to ±4 meV: the error quoted here (125 meV) represents the spread of values currently accepted for the work function of the NHE.
2
Errors reflect stability of rest potential measurement. Repeat measurement (see bare chip repeat) indicates a run-to-run variation of ±5% (the error bars used in Figure 2b).