An enzymatic biosensor for hydrogen peroxide based on one-pot preparation of CeO2-reduced graphene oxide nanocomposite

作者：Radhakrishnan Sivaprakasam; Kim Sang Jae^*

来源：RSC Advances, 2015, 5(17): 12937-12943.

DOI：10.1039/c4ra12841a

The study describes cerium oxide-reduced graphene oxide (CeO2-rGO) prepared by a facile one-pot hydrothermal approach and its assembly with horseradish peroxidase (HRP) for the detection of hydrogen peroxide (H2O2) at trace levels. The prepared nanocomposite was characterized by Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, X-ray diffraction, and voltammetry. Furthermore, the direct electrochemistry of HRP/CeO2-rGO composite has been studied. The immobilized enzyme retained its bioactivity and exhibited a pair of well-defined redox peaks, confirming the direct electron transfer (DET) of HRP with CeO2-rGO composite modified electrode. A significant enzyme loading (4.270 x 10(-10) mol cm(-2)) has been obtained on CeO2-rGO composite as compared to the bare glassy carbon (GC), CeO2, and rGO modified surfaces. This HRP/CeO2-rGO film has been used for the sensitive detection of hydrogen peroxide by voltammetry and it exhibited a wide linear range of H2O2 from 0.1 to 500 mM with a detection limit of 0.021 mM. The apparent Michaelis-Menten constant (Kapp M) of HRP on the CeO2-rGO composite was estimated as 0.011 mM. The combination of the direct electron transfer character of HRP and the promising feature of CeO2-rGO composite favors the sensitive determination of H2O2 with improved sensitivity.

• 出版日期2015