Solid-state nanopore analysis of alcohol-soluble molecules

We report on a modified solid-state nanopore measurement scheme to probe alcohol-soluble proteins. Taking advantage of the intrinsic alcohol solubility of LiCl as an electrolyte, we show that the devices can be operated in azeotropic mixtures of ethanol and water. We first characterize nanopore conductivity across a range of ethanol content as a function of both nanopore diameter and salt concentration, showing ionic response that can be understood through established models. Then, as a demonstration of resistive-pulse sensing, we measure and interpret electrical translocations of zeins, a class of alcohol-soluble maize protein.