A New Kind of Potassium Sensor Based on Capacitance Measurement of Mimic Membrane

A novel type of potassium sensor based on the capacitance change of valinomycin-incorporated bilayer supported on a gold electrode has been developed and characterized. The lipid membrane was formed by painted method and monitored simultaneously by capacitance variation. The capacitance of the electrode-supported membrane was found to be modulated by different concentrations of K+. Investigating the capacitance change allows a simple and specific technique for the measurement of potassium ion in solution. Especially, the homemade capacitance meter is, to our knowledge, used to monitor the bilayer membrane formation and detect K+ for the first time. It has been proved that this capacitance measurement is a very useful technique because it is simple and sensitive compared to the other methods.