Table 1.

The amount of proteins adsorbed on the working electrode of SPEs in relation to the surface preconditioning strategy and protein concentration. The values reported are averages of two replicates.

Electrode Preconditioning	Percentage of the Adsorbed Protein (%)
	BSA		Protein A
	10 μg mL−1 (100 ng in 10 μL)	20 μg mL−1 (200 ng in 10 μL)	10 μg mL−1 (100 ng in 10 μL)	20 μg mL−1 (200 ng in 10 μL)
None (pristine electrodes)	85	84	84	60
H2O2-treated	92	79	≥98 *	66
H2SO4-treated	81	86	85	33
Positive-plasma-treated	87	86	61	63
Negative-plasma-treated	84	85	≥82 *	47

* The mass of proteins aspirated from one of the electrodes was below the detection limit of the method.