Schematic (image) DOE/Brookhaven National Laboratory Caption This is a schematic illustration of the assembly of DNA-functionalized nanoparticles (NPs) at positively charged interfaces. (a) In the absence of salt, interactions are dominated by the electrostatic repulsion between DNA chains. (b) The 2D assemblies can be altered by programming the interactions between the NPs. By introducing monovalent salt, an attractive interaction between the NPs is switched ON, due to DNA hybridization. Change in interaction between NPs provides the path to tune the structure of the 2D assemblies at the interface. Credit Brookhaven National Laboratory Usage Restrictions For use with stories about this research. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.