(102g) A Novel Method for Measuring Proteins Zeta Potential Using Electroacoustics

It is known that measuring the zeta potential and valency of proteins in a physiological solution with high ionic strength presents a problem for traditional electrophoretic methods. High ionic strength leads to high current, thermal convection, and electrochemical contamination of the samples. This problem can be solved by using ultrasound waves instead of an electric field for moving protein molecules relative to the liquid. Propagation of ultrasound waves through a liquid containing charged entities creates an electric response called Colloid Vibration Current.  Here we use a device that is capable of measuring this electroacoustic effect for characterizing the electric properties of several proteins dissolved in water. We present results for protein samples in different ionic compositions of water, as well as a high ionic strength physiological solution. We also investigate the role of temperature by conducting temperature sweeps from ambient temperature up to 36 °C.