Fc(COOH)2@ zeolitic imidazolate frameworks-8/three-dimensional macroporous carbon for ascorbic acid sensing

A novel ascorbic acid (AA) electrochemical biosensor based on ferrocene dicarboxylic acid (Fc(COOH) 2 )/zeolitic imidazolate framework-8 (ZIF-8)/three-dimensional (3D) kenaf stem-derived macroporous carbon (3D-KSCs) was proposed for the first time. The formation and properties of Fc(COOH) 2 /ZIF-8/3D-KCSs nanocomposites were characterized by scanning electron microscopy, Fourier transform-infrared spectroscopy, N 2 adsorption/desorption isotherms, X-ray powder diffraction, and energy dispersive X-ray spectroscopy. The results showed that a large number of short rod-like ZIF-8/Fc(COOH) 2 was arrayed on the 3D-KSCs surface via a simple one-step hydrothermal method. Fc(COOH) 2 was firmly encapsulated into the pores of ZIF-8 simultaneously during the synthesis process of ZIF-8. The Fc(COOH) 2 /ZIF-8/3D-KCSs nanocomposites were employed to prepare integrated Fc(COOH) 2 /ZIF-8/3D-KSCs electrode directly for electrochemical AA sensing, and the integrated electrode showed better performance for AA detection than traditional enzyme-based biosensors and nonenzymatic sensors. A wide detection range of 0.06 μM~5.01 mM and a low detection limit of 0.017 μM were obtained with good stability and selectivity. The work also sheds new light on developing ZIF-8-based nanocomposites for electrochemical sensing. ᅟ