Table 1.

Contact angle average ± standard deviation (N = 3) of three liquids (water (WCA), formamide and diiodomethane) and calculated surface energies (γ_SV) and their polar $\left({\gamma }_{\text{S}}^{\text{p}}\right)$ and dispersive $\left({\gamma }_{\text{S}}^{\text{d}}\right)$ components of Au, SS, Al₂O₃ and ZrO₂ sensors, without (w/o) and with (w/) pellicle, and of S. gordonii layer. Work of adhesion (W_ad) between sensors, without and with pellicle, and S. gordonii.

	WCA; Water (deg)	Formamide (deg)	Diiodomethane (deg)	γSp (mJ/m2)	γSd (mJ/m2)	γSV (mJ/m2)	Wad (mJ/m2)
Au w/o pellicle	79.0 ± 1.0ab,A	51.6 ± 4.5	432 ± 1.1	5.0 ± 0.5	34.7 ± 1.2	39.7 ± 1.3	76.3
SS w/o pellicle	66.9 ± 5.6 a,A	60.1 ± 1.5	50.0 ± 0.9	14.1 ± 2.6	24.0 ± 3.4	38.1 ± 4.3	89.5
A12O3 w/o pellicle	73.4 ± 22 ab,A	59.4 ± 1.7	49.1 ± 2.0	9.4 ± 1.2	27.1 ± 1.9	36.5 ± 2.3	82.5
ZrO2 w/o pellicle	81.1 ± 1.8b,A	57.8 ± 1.6	41.1 ± 1.9	4.0 ± 0.5	34.5 ± 1.4	38.6 ± 1.4	73.0
Au w/ pellicle	48.3 ± 4.2 c,B	326 ± 6.8	41.9 ± 1.8	25.0 ± 1.9	27.6 ± 1.9	52.6 ± 2.7	109.4
SS w/ pellicle	47.3 ± 1.2 c,B	34.3 ± 13.3	402 ± 1.0	25.6 ± 2.5	27.3 ± 2.5	52.9 ± 3.5	110.0
Al2O3 w/ pellicle	50.2 ± 20 c,B	36.6 ± 2.3	42.4 ± 1.5	23.9 ± 1.4	27.2 ± 1.4	51.1 ± 2.0	107.6
ZrO2 w/ pellicle	51.7 ± 1.1 c,B	320 ± 3.0	41.0 ± 3.6	22.2 ± 0.9	29.0 ± 1.0	51.2 ± 1.3	106.4
S. gordonii	32.9 ± 1.9	27.0 ± 3.4	663 ± 2.0	47.4 ±1.4	14.9 ± 0.8	62.3 ± 1.6

Lower-case letters next to WCA values indicate statistical significance between different materials, either before (a, b) or after (c) pellicle formation. Upper-case letters next to WCA values indicate statistical significance for each material before and after pellicle formation. Groups with different letters were statistically significant different (p-value < 0.05).