TABLE 3.

Mass adsorption and viscoelastic properties calculated from QCM-D and SPR results

Sample	ΔmVoigt* (ng/cm2)	ΔmSPR† (ng/cm2)	Water content (mass %)	ρVoigt‡ (g/dm3)	dVoigt‡ (nm)	ηVoigt‡ (mPa/s)	μVoigt‡ (MPa)
ERE	655	102	84	1069	6.2	2.0	0.19
Ctrl ERα-ERE	1470	755	49	1168	12.6	4.3	0.55
E2-ERα-ERE	1270	516	59	1133	11.2	3.4	0.42
4OHT-ERα-ERE	1155	319	72	1093	10.6	2.4	0.23

^*Δm_Voigt value is obtained through viscoelastic modeling using the Voigt model for a one-layer film (see Materials and Methods).

^†Δm_SPR value calculated from their corresponding angle shift using the de Feijter formula with a conversion factor of 833 ng/(cm²/deg) for proteins (corresponding to dn/dc = 0.18) and 789 ng/(cm²/deg) for DNA (corresponding to dn/dc = 0.19).

^‡The effective density of the film was calculated by weighting from the modeled and measured masses Δm_Voigt and Δm_SPR, using a density of 1000, 1350, and 1700 g/dm³ for buffer, protein, and DNA, respectively (see Materials and Methods). This density was used in a subsequent iteration of modeling to find d_Voigt, η_Voigt, and μ_Voigt.