title: A novel organophosphorus hydrolase-based biosensor using mesoporous carbons and carbon black for the detection of organophosphate nerve agents.
abstract: To detect organophosphate chemicals, which are used both as pesticides and as nerve agents, a novel biosensor based on organophosphorus hydrolase was developed. By using mesoporous carbon (MC) and carbon black (CB) as an anodic layer, the sensitivity of the sensor to p-nitrophenol (PNP), which is the product of the organophosphorus hydrolase reaction, was greatly improved. The MC/CB/glass carbon (GC) layer exhibited an enhanced amperometric response relative to a carbon nanotube (CNT)-modified electrode because it promoted electron transfer of enzymatically generated phenolic compounds (p-nitrophenol). The well-ordered nanopores, many edge-plane-like defective sites (EDSs), and high surface area of the MC resulted in increased sensitivity, and allowed for nanomolar-range detection of the analyte paraoxon. Thus, MCs are suitable for use in real-time biosensors. Under the optimized experimental conditions, the biosensor had a detection limit of 0.12 microM (36 ppb) and a sensitivity of 198 nA/microM for paraoxon.
authors.affiliation: Graduate Program in Bioengineering, Seoul National University, Seoul 151-744, Republic of Korea.
authors.forename: Joon Hwan
authors.initials: JH
authors.lastname: Lee
authors.forename: Jae Yeon
authors.initials: JY
authors.lastname: Park
authors.forename: Kyoungseon
authors.initials: K
authors.lastname: Min
authors.forename: Hyung Joon
authors.initials: HJ
authors.lastname: Cha
authors.forename: Suk Soon
authors.initials: SS
authors.lastname: Choi
authors.forename: Young Je
authors.initials: YJ
authors.lastname: Yoo
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002619:Chemical Warfare Agents / Q000032:analysis*; D003217:Conductometry / Q000295:instrumentation* / Q000379:methods; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D009498:Neurotoxins / Q000032:analysis*; D010755:Organophosphates / Q000032:analysis* / Q000737:chemistry; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053260:Soot / Q000737:chemistry*
chemical_list: D002619:Chemical Warfare Agents; D004800:Enzymes, Immobilized; D037742:Nanotubes, Carbon; D009498:Neurotoxins; D010755:Organophosphates; D053260:Soot; C045290:phosphorylphosphatase; D010744:Phosphoric Monoester Hydrolases