title: Palladium nanoparticle/chitosan-grafted graphene nanocomposites for construction of a glucose biosensor.
abstract: Graphene (GR) was covalently functionalized with chitosan (CS) to improve its biocompatibility and hydrophilicity for the preparation of biosensors. The CS-grafted GR (CS-GR) rendered water-soluble nanocomposites that were readily decorated with palladium nanoparticles (PdNPs) using in situ reduction. Results with TEM, SEM, FTIR, Raman and XRD revealed that CS was successfully grafted without destroying the structure of GR, and PdNPs were densely decorated on CS-GR sheets with no aggregation occurring. A novel glucose biosensor was then developed through covalently immobilizing glucose oxidase (GOD) on a glassy carbon electrode modified with the PdNPs/CS-GR nanocomposite film. Due to synergistic effect of PdNPs and GR, the PdNPs/CS-GR nanocomposite film exhibited excellent electrocatalytical activity toward H(2)O(2) and facilitated high loading of enzymes. The biosensor demonstrated high sensitivity of 31.2 μA mM(-1)cm(-2) for glucose with a wide linear range from 1.0 μM to 1.0mM as well as a low detection limit of 0.2 μM (S/N=3). The low Michaelis-Menten constant (1.2mM) suggested enhanced enzyme affinity to glucose. These results indicated that PdNPs/CS-GR nanocomposites held great potential for construction of a variety of electrochemical biosensors.
authors.affiliation: State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Zeng
authors.forename: Jin-Sheng
authors.initials: JS
authors.lastname: Cheng
authors.forename: Xiao-Fei
authors.initials: XF
authors.lastname: Liu
authors.forename: Hao-Tian
authors.initials: HT
authors.lastname: Bai
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Jiang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D048271:Chitosan / Q000737:chemistry; D004566:Electrodes; D005947:Glucose / Q000032:analysis*; D006108:Graphite / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D015203:Reproducibility of Results
chemical_list: D010165:Palladium; D006108:Graphite; D048271:Chitosan; D005947:Glucose