Carbon and oxygen were found in both PEG and alanine. This confirmed that all components participated in the nanozyme fabrication (Figure , Figure ). The presence of iron in the mapping image and its quantification profile validated minimum leaching during the particle fabrication and subsequent centrifuge step (Figure ). Thus, this localization of iron represents the coordinated bonding formation with other elements to form the ligands, indirectly demonstrating the possibility of the existence of an active site.