A novel hydrogen peroxide biosensor based on Au–graphene–HRP–chitosan biocomposites

✍ Scribed by Kangfu Zhou; Yihua Zhu; Xiaoling Yang; Jie Luo; Chunzhong Li; Shaorong Luan

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 752 KB
• Volume: 55
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2010.01.035

✦ Synopsis

Graphene was prepared successfully by introducing -SO 3

-to separate the individual sheets. TEM, EDS and Raman spectroscopy were utilized to characterize the morphology and composition of graphene oxide and graphene. To construct the H 2 O 2 biosensor, graphene and horseradish peroxidase (HRP) were co-immobilized into biocompatible polymer chitosan (CS), then a glassy carbon electrode (GCE) was modified by the biocomposite, followed by electrodeposition of Au nanoparticles on the surface to fabricate Au/graphene/HRP/CS/GCE. Cyclic voltammetry demonstrated that the direct electron transfer of HRP was realized, and the biosensor had an excellent performance in terms of electrocatalytic reduction towards H 2 O 2 . The biosensor showed high sensitivity and fast response upon the addition of H 2 O 2 , under the conditions of pH 6.5, potential -0.3 V. The time to reach the stable-state current was less than 3 s, and the linear range to H 2 O 2 was from 5 × 10 -6 M to 5.13 × 10 -3 M with a detection limit of 1.7 × 10 -6 M (S/N = 3). Moreover, the biosensor exhibited good reproducibility and long-term stability.