Nanozymes (NZs) are catalytically active nanomaterials, which have enzyme-like activity, but possess increased stability and greater availability due to simpler preparation technologies. NZs as nanoscale artificial enzymes possess various catalytic specificities as oxidoreductases, such as peroxidase, catalase, laccase and others, as well as hydrolases, proteases, endonucleases, DNA-ases, NO synthases, etc. Many NZs exhibit dual- or multienzyme mimetic activity. NZs as stable low-cost mimetics of natural enzymes have a high potential for application in different branches of biotechnology, including scientific investigations, industry and ecology. NZs can be applied in medicine as diagnostic tools and components of therapeutic drugs. Since NZs have high catalytic activity and chemical and biological stability, they are very promising in construction of biosensors and biofuel cells. For these reasons, the search for simple methods of synthesis and characterization of different NZs is a very important and actual problem.
The “green” synthesis of Prussian blue analogous as peroxidase-like NZs using oxido-reductases is described in this study. The obtained green-synthesized hexacyanoferrates (gHCF) of transition metals were characterized by structure, size, composition, catalytic properties, electro-mediator activities and substrate specificity. Copper hexacyanoferrate (gCuHCF) was studied in more detail. When immobilized on a graphite electrode (GE), gCuHCF under special conditions of pH and tension, gives amperometric signals on hydrogen peroxide and therefore can be used as a peroxidase mimetic in oxidase-based biosensors. Under other conditions, gCuHCF/GE reacts to other analytes. We propose that gHCF of transition metals synthesized via enzymes may become prospect platforms for construction of multi-functional amperometric (bio)sensors.
Funding: This work was partially funded by NAS of Ukraine (The program “Smart sensor devices and technologies”), by the Ministry of Education and Science of Ukraine (Ukrainian- Lithuanian R&D Project # М/20 - 2020; 12.08.2020) and by the Research Authority of the Ariel University, Israel.