Figure 6.

Schematic illustrating charge sharing in a biosensor. The net charge of the adsorbed biomolecules on the sensor surface $\left({\sigma }_T\right)$ is shared between the sensor $\left({\sigma }_{\text{sensor}}\right)$ and the counterions present in the buffer $\left({\sigma }_{\text{DL}}\right)$. The independent parameter is the charge in the biomolecules and the potential of the molecular layer is determined by the relative values of the capacitances shown in the schematic.