Implications of Radioactive Exposure Observed

An international team led by researchers from the Max Planck Institute for Nuclear Physics in Heidelberg has observed intermolecular Coulombic decay in organic molecules. They found that the effect damages two neighboring molecules and ultimately leads to the breaking of bonds—like the ones in DNA and proteins. Their findings were published in Nature Chemistry. 

Until now, scientists had assumed that ionizing radiation damages biomolecules mainly indirectly. However, in their reaction microscope, the researchers observed that radioactive radiation can indeed break bonds. This instrument allows them not only to detect the two separating benzene molecules and measure their energy but also to characterize the electrons emitted.

“It is not yet clear how the intermolecular Coulombic decay affects the DNA strand,” lead researcher Alexander Dorn. If a single strand in the DNA ladder breaks, the consequences should not be too serious. However, the mechanism observed also releases several electrons that can further impact other pairs of molecules. 

In order to better assess the effect of the radiation on the genetic material, Dorn’s team will now also bombard pairs of nucleic acids with electrons under the reaction microscope. “This is experimentally challenging because we have to heat the nucleic bases in order to vaporize them,” explains Dorn. “But they must not get too hot either—so that they are not destroyed”. Nuclear doctors can also follow the trail to more effective sensitizers that the Heidelberg team has blazed with the observation of intermolecular Coulombic decay.