Copper-doped zeolite imidazole framework-8 (Cu/ZIF-8) was prepared and its peroxidase-like oxidative catalytic activity was examined with a demonstration of its applicability for cancer-cell imaging. Through simple solution chemistry at room temperature, Cu/ZIF-8 nanocrystals were produced that catalytically oxidized an organic substrate of o-phenylenediamine in the presence of H2O2. In a similar manner to peroxidase, the Cu/ZIF-8 nanocrystals oxidized the substrate through a ping-pong mechanism with an activation energy of 59.2 kJ mol−1. The doped Cu atoms functioned as active sites in which the active Cu intermediates were expected to be generated during the catalysis, whereas the undoped ZIF-8 did not show any oxidative activity. Cu/ZIF-8 nanocrystals exhibited low cell toxicity and displayed catalytic activity through interaction with H2O2 among various reactive oxygen species in a cancer cell. This oxidative activity in vitro allowed cancer-cell imaging by exploiting the photoluminescence emitted from the oxidized product of o-phenylenediamine, which was insignificant in the absence of the Cu/ZIF-8 nanocrystals. The results of this study suggest that the Cu/ZIF-8 nanocrystal is a promising catalyst for the analysis of the microbiological systems.
Bibliographical noteFunding Information:
This work was supported by the Korean Research Foundation Grant funded by the Korean government (MOEHRD) (NRF-2014K2A1B8046967) and by the Human Resources Program in Energy Technology of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), a financial resource grant from the Ministry of Trade, Industry & Energy, Republic of Korea (no. 20174010201640).
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All Science Journal Classification (ASJC) codes
- Organic Chemistry