Patent ID: 9103770
Filing Date: 2015-08-11
Classification: G01D,G01N,G01R,G06F

Abstract:
1. A method of determining an isoelectric point of a target molecule, the method comprising: measuring a first plurality of capacitance versus voltage curves of a capacitor, the capacitor comprising a substrate, a dielectric layer, and an electrically conductive solution; wherein the first plurality of capacitance versus voltage curves are measured for a plurality of pH values of the electrically conductive solution without the target molecule being bound to a functionalized material on the dielectric layer of the capacitor; measuring a second plurality of capacitance versus voltage curves of the capacitor when the target molecule is present in the electrically conductive solution, the target molecule being bound to the functionalized material of the dielectric layer of the capacitor; determining a shift in the second plurality of capacitance versus voltage curves from the first plurality of capacitance versus voltage curves at each of the plurality of pH values; and determining the isoelectric point of the target molecule by extrapolating a pH value that corresponds to a shift voltage being zero, when the shift at a plurality of shift voltages is compared to the plurality of pH values.