Biochemical characterization of enzyme-like silver nanoparticles toward nanozyme-catalysed oxidation reactions

Abstract

In this contribution, the biochemical characterization of enzyme-like nanosilvers was performed toward nanozyme-catalyzed oxidation reactions. In this regard, silver nanoparticles were synthesized via a simple chemical reduction method and then characterized by the TEM imaging method. Afterward, their enzyme-like activity was investigated toward catalysis of the oxidation reaction of 3,3’,5,5’-tetramethyl-benzidine (TMB) as one of the most popular peroxidase substrates. The results exhibited a specific nanozymatic activity as high as 5400 nM min−1 for the as-synthesized nanosilvers toward TMB oxidation. Due to the high enzyme-like activity ofthe as-prepared nanosilvers, their biochemical properties including pH, thermal, light, and shelf stability were characterized to explore more precisely describing their nanozymatic behavior. The results ofthermal and pH stability studies showed that the as-prepared nanosilvers reveal their maximal enzyme-like activity at a wide temperature range of 25℃–35℃ and a pH range of 3.5–4.5, in order. Regarding the light stability and shelf-life studies, the results exhibited that 75% and 96% of the enzyme-like activity of the as-prepared nanozymes was saved after 7 days exposing visible light and 10 days of storage at 4℃ under dark conditions, in order.