A facile microcontact printing method has been developed based on directly printing polyelectrolytes on a glass or polystyrene surface coated with poly(ethylene glycol) (PEG) silane using an unmodified poly(dimethyl siloxane) (PDMS) stamp. The method is applicable to a variety of polyelectrolytes including poly(allylamine hydrochloride) (PAH), poly(diallyldimethylammonium chloride) (PDAC), branched and linear poly(ethylene imine) (PEI), poly-L-lysine (PLL), chitosan, double stranded DNA, and poly(sodium 4-styrene sulfonate) (PSS). The printed polyelectrolyte structures, which include monolayer, bilayer, and stretched molecular bundles, are stable in aqueous solutions and have been used as templates for micropatterning quantum dot nanoparticles, DNA, proteins, and live cells.
