Co^sub 3^O^sub 4^/CuO hollow nanocage hybrids with high oxidase-like activity for biosensing of dopamine

• Published in: Materials Science & Engineering. C, Biomimetic Materials, Sensors and Systems Biomimetic Materials, Sensors and Systems, 2019-01, Vol.94, p.858
• Main Authors: Zhuang, Yunxia, Zhang, Xiaodan, Chen, Qiumeng, Li, Siqi, Cao, Haiyan, Huang, Yuming
• Format: Article
• Language: English
• Subjects: Biological properties; Biological samples; Biosensors; Carbonization; Catalysis; Cobalt oxides; Colorimetry; Copper; Copper oxides; Diffraction; Dissolved oxygen; Dopamine; EGR-1 protein; Hybrids; Hydrogen peroxide; Hydrothermal treatment; Materials science; Nanocomposites; Nanoparticles; Oxidase; Oxidation; Oxides; Photoelectron spectroscopy; Photoelectrons; Reactive oxygen species; Scanning electron microscopy; Substrates; Transmission electron microscopy; X-ray diffraction
• ISSN: 0928-4931; 1873-0191
• DOI: 10.1016/j.msec.2018.10.038

Here, we report the synthesis, characterization, and oxidase-like activity of Co3O4/CuO hollow nanocage (HNC) nanocomposites. The Co3O4/CuO HNCs were successfully prepared by hydrothermal treatment of ZIF-67 in copper nitrate solution, followed by carbonization in air. The obtained nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction. The Co3O4/CuO HNCs possess enhanced oxidase-like activity compared with pure Co3O4 and CuO, and they can catalytically oxidize the 3,3′,5,5′-tetramethylbenzidine (TMB) substrate in the absence of H2O2 to produce an intense blue product. Reactive oxygen species (ROS) measurements indicate that 1O2 and O2− radicals are the major ROS in catalytic oxidation of TMB by dissolved oxygen in the TMB–Co3O4/CuO HNC system. We then developed a simple, sensitive, visual, and colorimetric biosensing method for dopamine (DA) based on its inhibiting effect on TMB oxidation. The proposed method allows for DA detection with a limit of detection of 0.027 μM and a dynamic range of 0.05–8 μM. This new colorimetric method was successfully used to detect DA in biological samples. The present work demonstrates a simple strategy to fabricate an efficient oxidase mimic with potential applications in bioanalysis and clinical diagnosis.