How to Make a Nanocage (IMAGE) Washington University in St. Louis Caption Start with a silver (grey) nanocube with clipped corners. Dunk the cube in chloroauric acid (HAuCl4). Because gold (yellow) has greater affinity for electrons than does silver, the gold ions will pull electrons from the silver and precipitate on the silver cube. As this process continues, the silver cube is eroded from within, the silver ions leaving through pores that open in the clipped corners of the cube. As the gold skin approaches the desired thickness, the triangular corners become squared-off holes, a slightly more favorable configuration energetically. Credit Younan Xia, Washington University in St. Louis Usage Restrictions None License Licensed content 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.