title: Amperometric sensing of norepinephrine at picomolar concentrations using screen printed, high surface area mesoporous carbon.
abstract: Norepinephrine (NE) is detected amperometrically using the enzyme Phenylethanolamine N-methyl transferase and cofactor S-(5'-Adenosyl)-l-methionine chloride dihydrochloride with disposable screen printed mesoporous carbon electrodes. The role of internal surface area and pore size of the mesoporous carbon is systematically examined using soft-templated, mesoporous silica-carbon powders with highly microporous walls obtained from etching of the silica to produce powders with surface areas ranging from 671-2339 m(2)g(-1). As the surface area increases, the sensitivity of the biosensor at very low NE concentrations (0-500 pg mL(-1)) in phosphate buffered saline (PBS) increases just as the current signal increases with respect to the NE concentration of 81-1581 μA mL ng(-1) cm(-2) for the mesoporous carbons. The best performing electrode provides similar sensitivity in whole rabbit blood in comparison to PBS despite no membrane layer to filter the non-desired reactants; the small (<5 nm) pore size and large internal surface area acts to minimize non-specific events that decrease sensitivity.
authors.affiliation: Chemical Engineering Program, Arizona State University, Tempe, AZ 85287, United States. mingzhi.dai@asu.edu
authors.forename: Mingzhi
authors.initials: M
authors.lastname: Dai
authors.forename: Brittney
authors.initials: B
authors.lastname: Haselwood
authors.forename: Bryan D
authors.initials: BD
authors.lastname: Vogt
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: La Belle
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D002138:Calibration; D002244:Carbon; D055664:Electrochemical Techniques / Q000295:instrumentation* / Q000379:methods*; D004566:Electrodes; D057230:Limit of Detection; D009638:Norepinephrine / Q000032:analysis* / Q000097:blood; D010084:Oxidation-Reduction; D011817:Rabbits; D012680:Sensitivity and Specificity; D013499:Surface Properties
chemical_list: D002244:Carbon; D009638:Norepinephrine
keywords: Electrochemistry; Mesoporous carbon; Norepinephrine; Porous materials; Self-assembly; Sensor