Deep eutectic solvents-assisted synthesis of ZnCo2O4 nanosheets as peroxidase-like nanozyme and its application in colorimetric logic gate

Pyrophosphate (PPi) and pyrophosphatase (PPase) play a significant role in the therapy of arthritic and clinical diagnosis. In this study, we quickly synthesized ZnCo2O4 nanosheets (NSs) with excellent peroxidase catalytic activity in basic deep eutectic solvent (DES). It was found that PPi could inhibit the catalytic capability of ZnCo2O4 NSs transforming colorless o-phenylenediamine (OPD) into yellow oxidized OPD (oxOPD), and the absorbance falls down at 420 nm. However, if PPase was simultaneously present in the system, PPi would be hydrolyzed, leading to the restoration of peroxidase activity of ZnCo2O4 NSs. Therefore, paving a way for colorimetric analysis of PPi as well as PPase. Furthermore, on the basis of above colorimetric assay, an IMPLICATION logic gate was legitimately designed. With the advantages of fast-speed, low-cost and simplification, we firmly believe that our proposed system has a good potential for simple and fast clinic diagnosis of arthritic diseases, even has great significance in the fields of life sciences, environmental measurement and food safety.