title: Chitosan coated on the layers' glucose oxidase immobilized on cysteamine/Au electrode for use as glucose biosensor.
abstract: A glucose biosensor was developed via direct immobilization of glucose oxidase (GOD) by self-assembled cysteamine monolayer on Au electrode surface followed by coating chitosan on the surface of electrode. In this work, chitosan film was coated on the surface of GOD as a protection film to ensure the stability and biocompatibility of the constructed glucose biosensor. The different application ranges of sensors were fabricated by immobilizing varied layers of GOD. The modified surface film was characterized by a scanning electron microscope (SEM) and the fabrication process of the biosensor was confirmed through electrochemical impedance spectroscopy (EIS) of ferrocyanide. The performance of cyclic voltammetry (CV) in the absence and presence of 25 mM glucose and ferrocenemethanol showed a diffusion-controlled electrode process and reflected the different maximum currents between the different GOD layers. With the developed glucose biosensor, the detection limits of the two linear responses are 49.96 μM and 316.8 μM with the sensitivities of 8.91 μA mM(-1)cm(-2) and 2.93 μA mM(-1)cm(-2), respectively. In addition, good stability (up to 30 days) of the developed biosensor was observed. The advantages of this new method for sensors construction was convenient and different width ranges of detection can be obtained by modified varied layers of GOD. The sensor with two layers of enzyme displayed two current linear responses of glucose. The present work provided a simplicity and novelty method for producing biosensors, which may help design enzyme reactors and biosensors in the future.
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China; Department of Chemistry and Biology, College of Science, National University of Defense Technology, Changsha 410073, PR China. Electronic address: zzyw2010@126.com.
authors.forename: Yawen
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Chemistry and Biology, College of Science, National University of Defense Technology, Changsha 410073, PR China. Electronic address: liyunqiu83@aliyun.com.cn.
authors.forename: Yunqiu
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Chemistry and Biology, College of Science, National University of Defense Technology, Changsha 410073, PR China. Electronic address: wjwu67@126.com.
authors.forename: Wenjian
authors.initials: W
authors.lastname: Wu
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China. Electronic address: jiangyr@mail.csu.edu.cn.
authors.forename: Yuren
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Department of Chemistry and Biology, College of Science, National University of Defense Technology, Changsha 410073, PR China. Electronic address: brhu@yeah.net.
authors.forename: Biru
authors.initials: B
authors.lastname: Hu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D048271:Chitosan / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis; D003217:Conductometry / Q000295:instrumentation*; D003543:Cysteamine / Q000737:chemistry*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D005949:Glucose Oxidase / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D003543:Cysteamine; D006046:Gold; D048271:Chitosan; D005949:Glucose Oxidase; D005947:Glucose
keywords: Au electrode; Chitosan; Cysteamine; Glucose oxidase; Immobilization