Fabrication of poly(toluidine blue O)/carbon nanotube composite nanowires and its stable low-potential detection of NADH

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 595; no. 2; pp. 152 - 160
• Main Authors: Zeng, Jinxiang, Wei, Wanzhi, Wu, Ling, Liu, Xiaoyin, Liu, Kai, Li, Yi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2006; Elsevier Science
• Subjects: Biological and medical sciences; Biosensors; Biotechnology; Carbon nanotube; Composite nanowires; Fundamental and applied biological sciences. Psychology; Methods. Procedures. Technologies; NADH; Poly(toluidine blue O); Various methods and equipments; Carbon nanotube; Poly(toluidine blue O); NADH; Biosensors; Composite nanowires; Performance evaluation; Dinucleotide; Carbon nanotubes; Solid electrode; Electrochemical detector; Surface structure; Biosensor; Composite electrode
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2006.07.014

A new type of poly(toluidine blue O)/multiwall carbon nanotube (PTBO/MWNTs) composite nanowires was fabricated by two steps: first, the TBO monomer was assembled onto multiwall carbon nanotubes (MWNTs) to form TBO/MWNTs adduct. Then, the obtained TBO/MWNTs adduct was electropolymerized on a glassy carbon electrode (GCE) surface by cyclic voltammetry. The nanowires modified GCE was characterized with scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The PTBO/MWNTs composite nanowires modified electrode was applied to determinate NADH. Compared with bare GCE and MWNTs modified GCE, the PTBO/MWNTs composite nanowires modified GCE decreased the NADH oxidization overpotential by about 650 mV and 260 mV, respectively, with a much low peak potential at about 0.0 V (vs. SCE). The peak current response at PTBO/MWNTs composite nanowires modified GCE was about 4.5 times higher than that of ultrathin PTBO modified GCE, at the same peak potential. A linear range from 2.0 μM to 4.5 mM was observed with fast response (within 5 s) and a low detection limit of 0.5 μM (based on S/ N = 3). The current diminution to 1.0 mM NADH is lower than 10% in a period over 70 min shows that the PTBO/MWNTs composite nanowires modified GCE is quite stable. The better electrocatalytic behavior toward NADH oxidation at PTBO/MWNTs composite nanowires modified GCE suggests that the composite nanowires is an excellent platform for electrochemical sensing and biosensing.