Polyelectrolyte-coated liquid crystal droplets for detecting charged macromolecules

Chemically engineered liquid crystal droplets with stimuli responsive director configurations are attractive for sensing applications. Here, we find that the adsorption of positively charged poly(amido amine) (PAMAM) dendrimers on negatively charged poly(styrenesulfonate sodium) (PSS)-coated liquid crystal droplets can trigger a bipolar-to-radial configuration transition of the liquid crystal in the droplets, which can be easily detected with a polarizing optical microscope. The sensitivity of the PSS-coated liquid crystal droplets for detecting PAMAM dendrimers depends on the size and number of liquid crystal droplets as well as the dendrimer generation.