CAS Center of Excellence for Nanoscience, CAS Key Laboratory for Nanosystem & Hierarchical Fabrication, National Center for Nanoscience and Technology, 11 Beiyitiao Zhongguancun, Beijing 100190, China;CAS Center of Excellence for Nanoscience, CAS Key Laboratory for Nanosystem & Hierarchical Fabrication, National Center for Nanoscience and Technology, 11 Beiyitiao Zhongguancun, Beijing 100190, China;University of Chinese Academy of Sciences, Beijing 100049, China;Department of Orthopaedics, the 309th Hospital of the PLA, Beijing 100091, China
Abstract:
The development of high-efficiency peroxidase mimetics is highly desirable in view of high cost and low stability of natural enzymes. From the perspective of mimicking active site microenvironment at low cost, we herein report a novel histidine-functionalized graphene quantum dot (His-GQD)/hemin complex, which exhibits the highest catalytic rate for the peroxidase-based chromogenic reaction among the hemin-containing mimetics reported so far. Also, our peroxidase mimetic shows excellent tolerance to strongly acidic conditions and can function in a wide temperature range. Lineweaver-Burk plots and comprehensive electron paramagnetic resonance analysis reveal a ping-pong type catalytic mechanism for this mimetic. In addition, His-GQD/hemin demonstrates high efficiency and accuracy in detecting H2O2 and blood glucose. Our work provides an effective design of artificial enzymes for practical applications.
