Adenosine Triphosphatase-Stabilized ZIF-67 as Peroxidase Mimic for Rapid Detection of Glutathione

Zeolitic imidazole framework-67 (ZIF-67) was demonstrated to exhibit intrinsic peroxidase-like activity by using 3,3′,5,5′-tetramethylbenzidine (TMB) as a chromogenic substrate. However, due to the inherent defects in the chemical stability and thermal stability of ZIFs, the peroxidase-like activity of ZIF-67 was severely affected. Therefore, establishing a simple and effective method to enhance the stability of ZIF-67 is necessary. ATP was found to improve the catalytic activity of ZIF-67. On the one hand, compared with ZIF-67, the catalytic efficiency of ZIF-67/ATP increased by 796 %, 5010 % and 570 % at 25 °C, 30 °C and 40 °C, respectively. In addition, the catalytic activity of ZIF-67/ATP was also greatly enhanced at pH-4. On the other hand, compared with ATP, the catalytic rate of ZIF-67/ATP increased by 364 % after 10 min of incubation. Inspired by the high catalytic activity of ZIF-67/ATP, we used the ZIF-67/ATP peroxidase-like system for colorimetric detection of glutathione with the limit of detection (LOD) of 0.46 μM. Furthermore, the proposed method provides a perspective on stabilizing the structures of ZIFs and developing a simple and efficient detection method.