Facile synthesis of CDs@ZIF-8 nanocomposites as excellent peroxidase mimics for colorimetric detection of H2O2 and glutathione

Abstract

CDs@ZIF-8 nanocomposites with excellent peroxidase-like activity has been designed and synthesized as nanoenzymes by a facile one-pot method, and a colorimetric method for detecting H 2 O 2 and glutathione (GSH) has been developed. • The CDs@ZIF-8 nanocomposites were designed and synthesized by an one-pot method in solvent-free system. • This work is the first example of the CDs combined with MOFs used as nanoenzymes to detect H 2 O 2 and glutathione (GSH). • The combination of ZIF-8 and CDs enables the composites rapid electron transfer and excellent catalytic activity. • This system broadens the application of CDs@MOFs composite materials in biological analytical field. CDs@ZIF-8 nanocomposites are designed and synthesized as nanoenzymes by a novel one-pot synthetic method in solvent-free system, in which ZIF-8 framework protects CDs from the aggregation and quenching, increasing the participation of CDs for catalytic reactions. The embedding of CDs into ZIF-8 matrix is conducted to rapid electron transfer, and their synergetic effect promotes the composite materials to have superior peroxidase-like activity. CDs@ZIF-8 materials have catalyzed the oxidation of a typical colorimetric substrate 3,3′,5,5′-tetramethylbenzydine (TMB) in the presence of H 2 O 2 with the color changes from colorless to blue oxidized TMB (ox-TMB). A colorimetric approach could be established to detect H 2 O 2 and glutathione (GSH) due to the outstanding peroxidase-like activity of CDs@ZIF-8-a. This work gives a feasible strategy for the synthesis of CDs-based composite nanozyme with enhanced catalytic activity and thus broadens the application of CDs@MOFs materials in biological analytical field.