Fig. 8: Minimizing the noise scaling function (SN).
From: Pre-equilibrium biosensors as an approach towards rapid and continuous molecular measurements
a Investigating the optimal KD for two insulin receptors with \({{{{{{\rm{k}}}}}}}_{{{{{{\rm{on}}}}}}}={10}^{6.5}\) and \({{{{{{\rm{k}}}}}}}_{{{{{{\rm{on}}}}}}}={10}^{7.5}\), resolving an insulin concentration signal with \({f}_{T}=4/600\) Hz, \({f}_{S}=10{f}_{T}\), and \({T}_{0}=100\) pM. The noise scaling function (solid lines) achieves a minimum (vertical lines) at \({K}_{D}\approx 1\) nM for the slow receptor and \({K}_{D}\approx 300\) pM for the fast one. Also plotted are the asymptotes of SN for \({k}_{{off}}\to \infty\) (dashed lines) and for \({k}_{{off}}\to 0\) (dotted lines). b The optimal KD corresponding to the minimum SN was obtained for a range kon values for T0 = 0.001, 0.1, and 10 nM for insulin sensors with fT = 4/600 Hz (four harmonics, target period 600 s) and fT = 40/600 Hz (40 harmonics, target period 600 s). c The minimum achievable SN (corresponding to optimal KD values) for the same conditions as b.
