Systematic study on preparation of copper nanoparticle embedded porous carbon by carbonization of metal–organic framework for enzymatic glucose sensor

Abstract

Recently, metal–organic frameworks (MOFs) have been widely used in the preparation of metal oxide-embedded porous carbon composite materials. However, non-oxidized metal nanoparticle embedded porous carbon composites have rarely been prepared from MOFs to date. Herein, we present a systematic synthetic condition study of a Cu nanoparticle embedded porous carbon composite (Cu@C-500) by simple carbonization of a copper-based MOF (HKUST-1). The conditions for the synthesis of the pure Cu nanoparticles embedded composite were optimized by changing the reaction temperature and time. The prepared composite retained its original octahedron shape, with uniformly distributed copper nanoparticles (∼30 nm) in the carbon bed. The composite Cu@C-500 exhibited hierarchical porosity with a moderate surface area (195 m² g⁻¹). Due to its hierarchical porosity and unique redox activity, Cu@C-500 was examined for peroxidase-like catalytic activity, particularly for glucose sensing assays. The results indicated that this carbon composite displayed high catalytic activity similar to that of the peroxidase enzyme. Moreover, it presented one of the best detection limits (3.2 × 10⁻⁹ M) in colorimetric glucose sensing. In addition, Cu@C-500 exhibited good selectivity towards other sugars. The high sensitivity and selectivity of Cu@C-500 show great potential in the development of highly efficient glucose sensing devices.