Copper Nanoclusters as Multienzymes Mimic Activities of Oxidase and Ascorbic Acid Oxidase in the Presence of Imidazole

Abstract

Artificial nanoenzymes based on metal nanoclusters have received great attention for multienzyme activities nowadays. In this work, pepsin-capped copper NCs (Cu-Pep NCs) are used as oxidase, ascorbic acid oxidase (AAO), and peroxidase mimics, and their activities are enhanced by the introduction of imidazole. The oxidase activity increased almost 7.5-fold, while 5-fold and 2fold increases were observed for the peroxidase and AAO-like activity, respectively. The enhanced radical formation in the presence of imidazole moieties facilitates the enzymatic activity of the Cu-Pep-NCs/Imid system. This work describes the different enzymatic activities of the NCs, paving a new way for artificial nanoenzymes having enhanced activities.

Cumulative Impact of Ligands on the Optical Properties of Ag21 Nanoclusters: Insights into the Relaxation Dynamics

“…Metal nanoclusters with atomic precision have attracted significant interest owing to their structural diversity and fascinating optical properties to find out various potential applications. − Synthesis of atomically precise NCs, understanding of their electronic structure, and electron–phonon coupling are essential to designing metal clusters with their tailored optical properties. − A few strategies have been used to synthesize highly luminescent metal clusters by tailoring several atoms and surface staple motifs. − Some of the efficient methods, such as one-pot reduction, ligand exchange, inter-NC reaction, thermodynamic and kinetic control over the desired product, etc., have been employed to fabricate stable thiolated Ag NCs. − The noncovalent interactions of ligands are crucial for the stability of the NCs. − It is reported that primary ligands (thiolates) protect the metal core only, and the thiolate and phosphine can stabilize the NCs. − Zheng et al have reported that the secondary PPh 3 ligand can shrink the Ag NC size and influence their luminescence property . Bakr et al have reported that the coligands of phosphines allow the NCs for high-quality crystal growth .…”