Simple and rapid method for synthesis of porous gold nanoparticles and its application in improving DNA loading capacity

Porous gold nanoparticles (GNPs) attracted considerable attention due to their remarkable properties. The porous GNPs due to the high surface area-to-volume ratio have potential applications in areas such as drug delivery, biosensors, and fuel cells. The most frequently used method for synthesis of porous GNPs is the de-alloying approach. Despite the benefits of this approach, the nanoparticles synthesized by this method were not very stable. Nevertheless, we report herein a novel, facile and simple method for synthesis of stable porous GNPs based on Tween 20-capped GNPs (Tween GNPs) and nitric acid. On the other hand, when DNA is loaded to GNPs surface, the resulted conjugates have the potential to be used in different fields such as biomedicine, materials science and especially in nano-biotechnology. Generally, the DNA loading on GNPs is performed using a salt-aging method and its incubating time takes about 24 h. Here, GNPs was replaced by porous GNPs and the incubation time for loading was reduced to 2 h without the needs for tedious salt addition process.