title: Tyramine detection using PEDOT:PSS/AuNPs/1-methyl-4-mercaptopyridine modified screen-printed carbon electrode with molecularly imprinted polymer solid phase extraction.
abstract: Tyramine (4-hydroxyphenethylamine), which is a monoamine metabolized by monoamine oxidase (MAO), exists widely in plants, animals, fermented foods, and salted foods. The incidence of hypertension, or "cheese effect", which is associated with a large dietary intake of tyramine while taking MAO inhibitors has been reported; therefore, the measurement of tyramine is an urgent concern. Herein, an efficient approach that integrates a molecular imprinting polymer for solid phase extraction (MISPE) technique with a sensitive electrochemical sensing platform (SPCE/PEDOT: PSS/AuNP/1-m-4-MP) for the quantification of tyramine is presented. Enhanced electrode conductivity was achieved sequentially by constructing a conductive polymer (PEDOT: PSS) on a screen-printed carbon electrode (SPCE), followed by electrodeposition with gold nanoparticles (AuNPs) and, finally, by modification with positively charged 1-methyl-4-mercaptopyridine (1-m-4-MP) using an Au-S bond. Tyramine was isolated selectively and pre-concentrated by the MISPE technique; electroanalysis that used differential pulse voltammetry (DPV) in NaOH (0.1M, pH 13) was conducted successively. Experimental parameters (such as modes of electrode modification, ratio of PEDOT: PSS, pH of electrolyte, time required for AuNP deposition, and 1-m-4-MP concentrations) that were associated with optimal detection conditions were evaluated also. We obtained a linear concentration range (5-100nM, R2=0.9939) with LOD and sensitivity at 2.31nM, and 3.11μAnM-1cm-2, respectively. The applicability of our technique was demonstrated by analyzing tyramine in spiked serum and milk. The feature of our newly developed analytical methods that coupled sample pre-treatment (sample clean-up and pre-concentration) with sensitive detection makes it a promising tool for quantifying of tyramine.
authors.affiliation: BioAnalytical Chemistry and Nanobiomedicine Laboratory, Department of Biochemical Science and Technology, National Taiwan University, Taipei, 10617 Taiwan.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Applied Chemistry, National Chi Nan University, Puli, Nantou, 545 Taiwan.
authors.forename: Cheng-Hung
authors.initials: CH
authors.lastname: Hsieh
authors.affiliation: Department of Applied Chemistry, National Chi Nan University, Puli, Nantou, 545 Taiwan.
authors.forename: Chi-Wei
authors.initials: CW
authors.lastname: Lai
authors.affiliation: BioAnalytical Chemistry and Nanobiomedicine Laboratory, Department of Biochemical Science and Technology, National Taiwan University, Taipei, 10617 Taiwan.
authors.forename: Ying-Feng
authors.initials: YF
authors.lastname: Chang
authors.affiliation: Department of Applied Chemistry, National Chi Nan University, Puli, Nantou, 545 Taiwan.
authors.forename: Hsin-Yi
authors.initials: HY
authors.lastname: Chan
authors.affiliation: Department of Applied Chemistry, National Chi Nan University, Puli, Nantou, 545 Taiwan.
authors.forename: Chang-Feng
authors.initials: CF
authors.lastname: Tsai
authors.affiliation: BioAnalytical Chemistry and Nanobiomedicine Laboratory, Department of Biochemical Science and Technology, National Taiwan University, Taipei, 10617 Taiwan.
authors.forename: Ja-An Annie
authors.initials: JA
authors.lastname: Ho
authors.affiliation: Department of Applied Chemistry, National Chi Nan University, Puli, Nantou, 545 Taiwan. Electronic address: lw25@ncnu.edu.tw.
authors.forename: Li-Chen
authors.initials: LC
authors.lastname: Wu
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D002244:Carbon / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry; D008892:Milk / Q000737:chemistry*; D054802:Molecular Imprinting / Q000295:instrumentation / Q000379:methods*; D011137:Polystyrenes / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry; D052616:Solid Phase Extraction / Q000295:instrumentation / Q000379:methods*; D013876:Thiophenes / Q000737:chemistry*; D014439:Tyramine / Q000032:analysis* / Q000097:blood*
chemical_list: D011137:Polystyrenes; D011725:Pyridines; D013876:Thiophenes; C533756:poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate); C042861:4-thiopyridine; D002244:Carbon; D006046:Gold; D014439:Tyramine
keywords: 1-Methyl-4-pyridine; Electrochemical analysis; Gold nanoparticles; PEDOT: PSS; Tyramine