Table 2.

Theoretical and experimental frequency shifts (∆f) determined after each phase of the bio-functionalization procedure of ZnO/GaAs biosensor (220 µm thick membrane) operating at the resonant frequency of 6.35 MHz (n = 3 samples).

Phase	Entity	$\left|\Delta \mathit{f} \right|\left(\mathbf{Hz}\right)$
		Theoretical	Experimental
Antibodies grafting	E. coli antibodies	39.84	27.1 ± 4.5
Passivation	BSA	136.46	59.8 ± 11.3