a fixative for biological tissue made up of polymerized carbon nanotubes encapsulating osmium nanoparticles and its method of synthesis are disclosed . carbon nanotubes are first oxidized . next , the oxidized carbon nanotubes and monohydrated citric acid are mixed to synthesize carbon nanotubes grafted with poly . the carbon nanotubes grafted with poly are then mixed with an osmium source to synthesize carbon nanotubes grafted with poly encapsulating osmium nanoparticles . the nano - fixative of this application has been shown to improve fixation of biological tissue relative to well - known fixatives .