文摘
Here we wish to demonstrate a unique property of nanomaterials: energy deposition with nanometer precisionfrom low-energy electrons released from these nanostructures interacting with hard X-ray radiation in aqueoussolution. Three effects combine to cause this phenomenon: (1) localized absorption of X-rays by nanostructures,(2) effective release of low-energy electrons from small nanostructures, and (3) efficient deposition of energyin water in the form of radicals and electrons. This combination creates localized X-ray absorption and localizedenergy deposition of nanometer precision. We confirmed the theoretically predicted nanoscale energy depositiondistribution by measuring hydroxyl radical-induced DNA strand breaks, and observed enhanced damage to a5600-bp DNA molecule from approximately 10 chemically conjugated small gold nanoparticles under X-rayradiation. These results provide a general guidance to applications of this new concept in many fields includingradiation chemistry, radiology, radiation oncology, biochemistry, biology, and nanotechnology.