title: Immobilization of glucose oxidase on graphene and cobalt phthalocyanine composite and its application for the determination of glucose.
abstract: We described a simple and facile chemical reduction strategy for the preparation of graphene (GR)-cobalt phthalocyanine (CoPc) composite and explored it for the enzymatic determination of glucose. CoPc is an active mediator and electrocatalysts for the immobilization of GOx and determination of glucose. However, it is not stable on the electrode surface and also suffers from lack of conductivity. Here, we have employed GR as the suitable support to stabilize CoPc through simple chemical reduction method and the resulting composite has been used for the glucose biosensor application. Scanning electron microscopy, X-ray diffraction and Energy-dispersive X-ray spectroscopy studies confirmed the successful formation of composite. Direct electron transfer of glucose oxidase (GOx) was observed with well defined redox peaks at the formal potential of -0.44 V. The amount of electroactive GOx (Г) and electron transfer rate constant (ks) were calculated to be 3.77×10(-10) mol cm(-2) and 3.57 s(-1), respectively. The fabricated amperometric biosensor detects glucose in wide linear concentration range from 10 μM to 14.8 mM with high sensitivity of 5.0 9μA mM(-1) cm(-2). The sensor offered very low detection limit (LOD) of 1.6 μM. In addition, practical feasibility of the sensor has been explored in screen printing carbon electrode with accurate determination of glucose present in human blood serum and urine samples. Furthermore, the sensor exhibited appreciable stability, repeatability and reproducibility results.
authors.affiliation: Electroanalysis and Bioelectrochemistry Lab, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC.
authors.forename: Veerappan
authors.initials: V
authors.lastname: Mani
authors.affiliation: Electroanalysis and Bioelectrochemistry Lab, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC.
authors.forename: Rajkumar
authors.initials: R
authors.lastname: Devasenathipathy
authors.affiliation: Electroanalysis and Bioelectrochemistry Lab, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC. Electronic address: smchen78@ms15.hinet.net.
authors.forename: Shen-Ming
authors.initials: SM
authors.lastname: Chen
authors.affiliation: Institute of Biochemical and Biomedical Engineering, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, ROC. Electronic address: ws75624@ntut.edu.tw.
authors.forename: Sheng-Tung
authors.initials: ST
authors.lastname: Huang
authors.affiliation: Department of Natural Products Chemistry, Madurai Kamaraj University, Madurai, Tamil Nadu, India.
authors.forename: V S
authors.initials: VS
authors.lastname: Vasantha
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D001786:Blood Glucose / Q000032:analysis; D058266:Dielectric Spectroscopy; D004800:Enzymes, Immobilized; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase; D006108:Graphite; D006801:Humans; D007211:Indoles; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D009942:Organometallic Compounds; D015203:Reproducibility of Results; D013052:Spectrometry, X-Ray Emission; D016482:Urinalysis / Q000379:methods; D014961:X-Ray Diffraction
chemical_list: D001786:Blood Glucose; D004800:Enzymes, Immobilized; D007211:Indoles; D009942:Organometallic Compounds; C063633:cobalt phthalocyanine; D006108:Graphite; D005949:Glucose Oxidase; D005947:Glucose
keywords: Amperometry; Biosensor; Cobalt phthalocyanine; Glucose oxidase; Graphene; Practicality