Nanozymes are a new and versatile class of artificial enzymes that have similar catalytic properties as the natural enzymes. They have wide application and utilization in the fields of environmental research, biomedicine, and industrial catalysis because of their significant characteristics, such as enhanced stability, cost-effectiveness, robustness, and improved catalytic activity as compared to the natural enzymes. Most of the commonly used nanozymes possess oxidoreductase-like properties and are capable of controlling cellular redox equilibrium. Functionalization of nanozymes after synthesis is a process to modulate their catalytic activity, which expands the range of their uses. This abstract demonstrates various approaches to synthesize nanozymes, such as sol-gel, co-precipitation, solvothermal, and hydrothermal techniques. To improve enzymatic activity, focus was made upon controlling particle size, shape, and surface chemistry, as well as the effects of doping, alloying, and composite formation. The chapter demonstrates some methods that enhance stability, targeting specificity, and biocompatibility in physiological settings, including polymer coatings, ligand attachment, and biomolecule conjugation. There is a need for time for future research to focus on precise control over nanozyme designs and the investigation of innovative functionalization approaches to open up new possibilities in both academic research and industry applications.