Safe Functional Modified CuO Nanoparticles?

CuO nanoparticles produced by methods from inorganic chemistry and physics are applied as biocides and applications thereof in solar stills, solar collectors, catalysis, sensing and diesel fuels have been proposed. Such CuO nanoparticles are hazardous due to the release of Cu ions and the induced generation of reactive oxygen species after uptake by organisms. Nanoparticle hazard may be reduced by surface modification (coating or capping) and doping which reduces the release of Cu ions and the generation of reactive oxygen species. None of the published safe-by-design modifications of CuO nanoparticles that will be discussed here have been proven safe (no risk). By targeting the release of Cu ions and the generation of reactive oxygen species by CuO nanoparticles, safe(r)-by-design studies target properties that underly the biocidal functionality of CuO nanoparticles. Other functionalities of CuO nanoparticles may also be impacted. There is a case for complementing safe(r)-by-design studies by investigating the impact of the modifications studied on CuO nanoparticle functionality.