ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Ascorbic acid amperometric sensor using a graphene-wrapped hierarchical TiO2 nanocomposite

Li Fu, Yu-Hong Zheng, and Zhu-Xian Fu

Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing Botanical Garden, Mem. Sun Yat-Sen, Nanjing 210014, China

E-mail: lifugyt@gmail.com

Abstract: An ascorbic acid (AA) amperometric sensor was fabricated based on a glassy carbon electrode (GCE) modified with a reduced graphene oxide-wrapped hierarchical TiO₂ (RGO-TiO₂) nanocomposite. The RGO-TiO₂ nanocomposite was synthesized via the facial wet chemical method and characterized by scanning electron microscopy and X-ray diffraction. Cyclic voltammetry and amperometric techniques were employed to investigate its electrocatalytic performance towards the AA oxidation. The combined advantages of RGO and TiO₂ provide the electrode with higher current response and lower oxidation potential compared with those of bare GCE and TiO₂ modified GCE. The proposed electrode can be used for the determination of AA in the wide concentration range from 1 to 1500 μM with the detection limit of 0.5 μM. The proposed electrode was successfully used to determine AA in vitamin C tablets and spiked fruit juice.

Keywords: ascorbic acid – reduced graphene oxide – nanocomposite – sensor – vitamin C

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0079

Chemical Papers 69 (5) 655–661 (2015)