title: Photoamperometric flow injection analysis of glucose based on dehydrogenase modified quantum dots-carbon nanotube nanocomposite electrode.
abstract: In this work, a core-shell quantum dot (QD, ZnS-CdS) was electrodeposited onto multiwalled carbon nanotube modified glassy carbon electrode (ZnS-CdS/MWCNT/GCE) and following glucose dehydrogenase (GDH) was immobilized onto QD modified electrode. The proposed electrode (GDH/ZnS-CdS/MWCNT/GCE) was effectively used for the photoelectrochemical biosensing of glucose in flow injection analysis (FIA) system using a home-made flow cell. Results from cyclic voltammetric and FI amperometric measurements have revealed that GDH/ZnS-CdS/MWCNT/GCE is capable of signaling photoelectrocatalytic activity toward NADH when the surface of enzyme modified electrode was irradiated with a light source (250W Halogen lamp). Thus, photoelectrochemical biosensing of glucose was monitored by recording current-time curve of enzymatically produced NADH at optimized conditions. The biosensor response was found linear over the range 0.010-2.0mM glucose with detection limits of 6.0 and 4.0μM for amperometric and photoamperometric methods, respectively. The relative standard deviations (n=5) for 0.5mM glucose were 5.8% and 3.8% for photoamperometric and amperometric results, respectively. The photoelectrochemical biosensor was successfully applied to the real samples. The results with this biosensor showed good selectivity, repeatability and sensitivity for monitoring glucose in amperometric and photoamperometric FIA studies.
authors.affiliation: Çanakkale Onsekiz Mart University, Science and Art Faculty, Department of Chemistry, 17020 Çanakkale, Turkey.
authors.forename: Bensu
authors.initials: B
authors.lastname: Ertek
authors.affiliation: Çanakkale Onsekiz Mart University, Science and Art Faculty, Department of Chemistry, 17020 Çanakkale, Turkey. Electronic address: ydilgin@yahoo.com.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Dilgin
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods*; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D042843:Glucose 1-Dehydrogenase / Q000737:chemistry / Q000378:metabolism*; D057230:Limit of Detection; D009243:NAD / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry; D037742:Nanotubes, Carbon / Q000737:chemistry*; D055668:Photochemical Processes; D045663:Quantum Dots / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D013440:Sulfides; D017967:Zinc Compounds; C034939:cadmium sulfide; D009243:NAD; D042843:Glucose 1-Dehydrogenase; D005947:Glucose; C031238:zinc sulfide
keywords: Flow injection analysis; Glucose dehydrogenase; Multiwalled carbon nanotube; NADH; Photoelectrochemical biosensor; ZnS-CdS quantum dots