The main objectives of this research project are the development and testing of novel nanocomposite materials for real-time radiation detectors that will minimize risks and exposure during human exploration missions. Developing and testing new materials for improved safety and health during human exploration beyond near Earth orbit cannot occur without a validated approach to addressing astronaut health risks due to radiation. This requires characterization of the space radiation environment, experimental validation of radiation protection methodologies, and the ability to predict and monitor the radiation absorbed by astronauts on a real-time and mission-integrated basis. As of 2019, the deep-space radiation environment is reasonably characterized, but real-time radiation monitors have not been fully addressed. For example, real-time radiation monitors are currently utilized on the International Space Station with inconsistent results, and they are not integrated with space-suits. Additional development is needed for active crew personnel dosimetry, including methods to incorporate dosimeters on space-suits. Therefore, this research proposal will focus on developing real time low weight and low power consumption radiation monitoring devices using carbon nanomaterials (such as graphene), which can also be fully integrated with the spacesuits of astronauts. These sensors will be realized by combining a biological element sensitive to ultraviolet radiation, double-stranded DNA, with conductive nanomaterial based on graphene and a polymer matrix acting as support. Among the technological problems that hinder the realization of this type of sensors, the ability to disperse carbon nanomaterials inside a polymer matrix is certainly a major issue. To this end, the same DNA component will be used to improve the dispersion of graphene, in addition to confer UV sensitivity to the nanocomposite material.
The UV-sensitive materials based on the hybrid graphene/DNA technology proposed in this project represent an innovative approach in Italian research, and will contribute to increase the visibility of the research of Sapienza University in the field of UV sensors at international level. At present, devices capable of measuring exposure to UV-C radiation still suffer from problems of bulk and weight, so they are not suitable for use in space environments. Furthermore, current sensors are unable to detect damage caused by biological UV radiation in real time. Commonly used devices, such as those based on spores, include a post-radiation analysis phase in the laboratory to determine the damage created by spore radiation.
The technology with real-time detection capability in this project is suitable to be used for the detection of biological damage induced by ultraviolet radiation during space missions, for example mapping dangerous radiation exposure on the human body. In addition, sensors containing the graphene/DNA element could be useful for real-time monitoring of biological damage in areas on Earth where exposure to the most energetic ultraviolet radiation occurs. This is the case of the equatorial zones where the ozone layer, which acts as a filter in particular for the UV-C band, is thinner.
In general, it is expected that the results of this project, thanks to the high sensitivity to UV radiation of the graphene/DNA element, will determine a substantial improvement in the monitoring of UV-induced biological damage in real time and in situ. This is important in all those extreme environments subject to high levels of ionizing UV radiation, which may have both natural (solar radiation) or artificial origin, including industrial plants that use UV-C radiation sources for sterilization of biomedical materials.