title: Simultaneous determination of ascorbic acid, dopamine and uric acid based on tryptophan functionalized graphene.
abstract: A new type of tryptophan-functionalized graphene nanocomposite (Trp-GR) was synthesized by utilizing a facile ultrasonic method via π-π conjugate action between graphene (GR) and tryptophan (Trp) molecule. The material as prepared had well dispersivity in water and better conductivity than pure GR. The surface morphology of Trp-GR was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) were investigated by cyclic voltammetry (CV) on the surface of Trp-GR. The separation of the oxidation peak potentials for AA-DA, DA-UA and UA-AA was about 182 mV, 125 mV and 307 mV, which allowed simultaneously determining AA, DA, and UA. Differential pulse voltammetery (DPV) was used for the determination of AA, DA, and UA in their mixture. Under optimum conditions, the linear response ranges for the determination of AA, DA, and UA were 0.2-12.9 mM, 0.5-110 μM, and 10-1000 μM, with the detection limits (S/N=3) of 10.09 μM, 0.29 μM and 1.24 μM, respectively. Furthermore, the modified electrode was investigated for real sample analysis.
authors.affiliation: Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070, PR China.
authors.forename: Qianwen
authors.initials: Q
authors.lastname: Lian
authors.affiliation: Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070, PR China.
authors.forename: Zhifang
authors.initials: Z
authors.lastname: He
authors.affiliation: Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: He
authors.affiliation: Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070, PR China.
authors.forename: Ai
authors.initials: A
authors.lastname: Luo
authors.affiliation: Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070, PR China.
authors.forename: Kaiwang
authors.initials: K
authors.lastname: Yan
authors.affiliation: Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070, PR China.
authors.forename: Dongxia
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070, PR China. Electronic address: Luxq@nwnu.edu.cn.
authors.forename: Xiaoquan
authors.initials: X
authors.lastname: Lu
authors.affiliation: Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070, PR China. Electronic address: zhouxb@nwnu.edu.cn.
authors.forename: Xibin
authors.initials: X
authors.lastname: Zhou
mesh_terms: D001205:Ascorbic Acid / Q000032:analysis* / Q000378:metabolism; D004298:Dopamine / Q000032:analysis* / Q000378:metabolism; D055664:Electrochemical Techniques; D004566:Electrodes; D006108:Graphite / Q000737:chemistry* / Q000378:metabolism; D015394:Molecular Structure; D053761:Nanocomposites / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties; D014364:Tryptophan / Q000737:chemistry* / Q000378:metabolism; D014527:Uric Acid / Q000032:analysis* / Q000378:metabolism
chemical_list: D014527:Uric Acid; D006108:Graphite; D014364:Tryptophan; D001205:Ascorbic Acid; D004298:Dopamine
keywords: Ascorbic acid; Dopamine; Graphene; Simultaneous determination; Tryptophan; Uric acid