Si, Yunpei Park, Yae Eun Lee, Ji Eun Lee, Hye Jin 2024-01-19T17:32:23Z 2024-01-19T17:32:23Z 2021-09-05 2020-05-21 0003-2654 https://pubs.kist.re.kr/handle/201004/118611 A sensitive electrochemical sensor featuring novel composites of gold and carbon nanocomplexes alongside a polymerized amino acid was developed for the determination of uric acid (UA) and dopamine (DA) concentrations in both buffer and human urine sample solutions. The sensor was fabricated by electropolymerization of l-methionine (l-Met) followed by coating of carbon nanotube-graphene complexes and electrodeposition of gold nanoparticles on a screen printed carbon electrode surface. The electrode surfaces were characterized by field emission scanning electron microscopy and energy dispersive spectroscopy, and the electrochemical properties were investigated by cyclic voltammetry and differential pulse voltammetry. Linear ranges of 0.05-3 mu M and 1-35 mu M with limits of detection of 0.0029 and 0.034 mu M were achieved for DA and UA, respectively. In addition, the developed sensor was applied for the analysis of native UA and DA concentrations in undiluted and diluted human urine samples. The UA analysis results were compared to those obtained using high performance liquid chromatography and a fluorometric assay kit while the DA analysis results were compared to those obtained using liquid chromatography-tandem mass spectrometry. English Royal Society of Chemistry PERFORMANCE LIQUID-CHROMATOGRAPHY ASCORBIC-ACID SELECTIVE DETECTION VOLTAMMETRIC DETERMINATION OXIDE NANOCOMPOSITES SENSOR HYPOXANTHINE METABOLITES CAPILLARY XANTHINE Nanocomposites of poly(l-methionine), carbon nanotube-graphene complexes and Au nanoparticles on screen printed carbon electrodes for electrochemical analyses of dopamine and uric acid in human urine solutions Article 10.1039/c9an02638j 1 Analyst, v.145, no.10, pp.3656 - 3665 Analyst 145 10 3656 3665 scie scopus 000536789000019 2-s2.0-85084936994 Chemistry, Analytical Chemistry Article PERFORMANCE LIQUID-CHROMATOGRAPHY ASCORBIC-ACID SELECTIVE DETECTION VOLTAMMETRIC DETERMINATION OXIDE NANOCOMPOSITES SENSOR HYPOXANTHINE METABOLITES CAPILLARY XANTHINE