Sensitive Electrochemical Detection of Enzymatically-generated Thiocholine at Carbon Nanotube Modified Glassy Carbon Electrode

Journal Article · Tue Nov 01 04:00:00 EST 2005 · Electrochemistry Communications

DOI:https://doi.org/10.1016/j.elecom.2005.08.025· OSTI ID:860424

Liu, Guodong; Riechers, Shawn L; Mellen, Maria C; Lin, Yuehe

A carbon nanotube modified glassy-carbon (CNT/GC) electrode was used for enhancing the sensitivity of electrochemical measurements of enzymatically-generated thiocholine. Cyclic voltammetric and amperometric characteristics of thiocholine at CNT/GC, glassy carbon, carbon paste, and gold electrodes were compared. The CNT layer leads to a greatly improved anodic detection of enzymatically generated thiocholine product including lower oxidation overpotential (0.15 V) and higher sensitivity because of its electrocatalytic activity, fast electron transfer and large surface area. The sensor performance was optimized with respect to the operating conditions. Under the optimal batch conditions, a detection limit of 5 ?10 -6 mol/L was obtained with good precision (RSD = 5.2%, n=10). Furthermore, the attractive response of thiocholine on a CNT/GC electrode has allowed it to be used for constant-potential flow injection analysis. The detection limit was greatly improved to 0.3 ?10-6 mol/L. The high sensitivity electrochemical detection of enzymatically generated thiocholine with a CNT sensing platform holds great promise to prepare an acetylcholinesterase biosensor for monitoring organophosphate pesticides and nerve agents.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 860424
• Report Number(s): PNNL-SA-46422; 12490; 6899
• Journal Information: Electrochemistry Communications, Journal Name: Electrochemistry Communications Journal Issue: 11 Vol. 7
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CARBON
Carbon nanotubes
DETECTION
ELECTRODES
ELECTRON TRANSFER
GOLD
MONITORING
NANOTUBES
NERVES
OXIDATION
PERFORMANCE
PESTICIDES
SENSITIVITY
biosensor
environmental molecular sciences laboratory