title: Graphene-loaded nanofiber-modified electrodes for the ultrasensitive determination of dopamine.
abstract: A novel and highly sensitive electrochemical system based on electrospun graphene/polyaniline/polystyrene (G/PANI/PS) nanofiber-modified screen-printed carbon electrodes has been developed for dopamine (DA) determination. A dramatic increase (9 times) in the current signal for the redox reaction of a standard, ferri/ferrocyanide [Fe(CN)6](3-/4-) couple was found when compared to an unmodified electrode. This modified electrode also exhibited favorable electron transfer kinetics and excellent electrocatalytic activity toward the oxidation of DA. When used together with square wave voltammetry (SWV), DA can be selectively determined in the presence of the common interferents (i.e. ascorbic acid and uric acid). Under optimal conditions, a very low limit of detection (0.05 nM) and limit of quantification (0.30 nM) were achieved for DA. In addition, a wide dynamic range of 0.1 nM to 100 μM was found for this electrode system. Finally, the system can be successfully applied to determine DA in complex biological environment (e.g. human serum, urine) with excellent reproducibility.
authors.affiliation: Metallurgy and Materials Science Research Institute, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand. Electronic address: Nadnudda.R@chula.ac.th.
authors.forename: Nadnudda
authors.initials: N
authors.lastname: Rodthongkum
authors.forename: Nipapan
authors.initials: N
authors.lastname: Ruecha
authors.forename: Ratthapol
authors.initials: R
authors.lastname: Rangkupan
authors.forename: Richard W
authors.initials: RW
authors.lastname: Vachet
authors.forename: Orawon
authors.initials: O
authors.lastname: Chailapakul
mesh_terms: D004298:Dopamine / Q000032:analysis*; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D057230:Limit of Detection; D008855:Microscopy, Electron, Scanning; D057139:Nanofibers
chemical_list: D006108:Graphite; D004298:Dopamine
keywords: Dopamine; Electrospinning; Graphene; Nanofiber; Polyaniline; Polystyrene