0 × 10−10 M)/HSA (1.0 × 10−10 M), BSA (1.0 × 10−10 M)/IgG selleck (1.0 × 10−10 M) and BSA (1.0 × 10−10 M)/HSA (1.0 × 10−10 M)/IgG (1.0 × 10−10 M) were injected into the capacitive system. Pre-mixed protein solutions caused a lower capacitance change compared to the

singular standard BSA solution. This difference could be stemmed from the competitive effects of HSA and IgG proteins. However, it could be clearly observed that, the BSA imprinted electrode showed high affinity for the template protein (BSA) and the electrode could detect BSA in singular manner and also under competitive conditions. The calculated selectivity coefficients are summarized in Table 1. Due to the results, the BSA imprinted capacitive electrode exhibited good selectivity for the template protein, BSA, compared

to other proteins with cross-reactivities of 5 and 3% against HSA and IgG, respectively. Real time BSA detection was also selleck screening library performed with NIP-electrodes. Standard BSA solutions in the concentration range of 1.0 × 10−20–1.0 × 10−6 M were prepared in the running buffer (10 mM phosphate, pH 7.4) and the analyses were identical to that with the imprinted electrodes. No change in the capacitance could be observed for the lower BSA concentrations. The limit of detection (LOD) was determined to be 1.0 × 10−10 M, based on IUPAC recommendations. To evaluate the analytical efficiency of the imprinting procedure, standard BSA second (1.0 × 10−10 M), HSA (1.0 × 10−10 M) and IgG (1.0 × 10−10 M) solutions were injected to the capacitive system in a serial manner (Fig. 6(B)). It was observed that, there was no significant difference in the capacitance change with the changing proteins for the NIP electrode. The change in capacitance was almost in the

same value for all three. The calculated selectivity coefficients for NIP electrode were 1.07 and 0.376 for BSA, compared to HSA and IgG, respectively (Table 1). There was a big difference in the selectivity coefficients of NIP and BSA imprinted electrode. These results indicate that, the imprinting of the protein onto the electrode surface generates cavities highly specific for the template protein. In addition, the imprinting efficiency values were calculated and the results are summarized in Table 1. The enhanced selectivity coefficients of the BSA imprinted capacitive sensor according to competing proteins are approximately 21 and 85 for BSA against HSA and IgG, respectively. The BSA imprinted electrodes were evaluated in terms of reproducibility by monitoring the capacitance change (−pF cm−2) at the same concentration of standard BSA solution (1.0 × 10−10 M) for 70 times. After injection and equilibration periods, in total 15 min, regeneration buffer was injected during 2.5 min before running buffer was used for reconditioning until the original baseline signal was achieved. The capacitance of the BSA imprinted sensor versus the number of injections is shown in Fig. 7.