Monodispersed gold nanoparticles entrapped in ordered mesoporous carbon/silica nanocomposites as xanthine oxidase mimic for electrochemical sensing of xanthine

• Published in: Mikrochimica acta (1966) Vol. 187; no. 10; p. 543
• Main Authors: Wang, Yiran, Zhao, Hongbin, Song, Huixian, Dong, Junping, Xu, Jiaqiang
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.10.2020; Springer; Springer Nature B.V
• Subjects: Analytical Chemistry; Carbon; Catalytic activity; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Electrodes; Gold; Iron compounds; Microengineering; Nanochemistry; Nanocomposites; Nanoparticles; Nanotechnology; Original Paper; Oxidases; Purines; Self-assembly; Sensors; Silicon dioxide; Ultrafines; Voltammetry; Xanthine oxidase; Mesoporous carbon/silica; Au nanoparticles; Enzyme mimic; Xanthine; Oxidase-like activity
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-020-04494-2

Monodispersed Au nanoparticles in ordered mesoporous carbon/silica (Au/OMCS) nanocomposites were prepared by the solvent evaporation induced self-assembly. Au/OMCS nanocomposites were characterized through XRD, BET, and TEM. The obtained nanocomposites exhibit uniform mesopores with the size of 18 ± 2 nm. And ultrafine Au nanoparticles with the size of 3~7 nm are well dispersed in the cavities. An ultrasensitive nanoenzyme sensor was fabricated based on a Au/OMCS-modified electrode. The Au/OMCS-modified electrode displays high xanthine oxidase–like catalytic activity evaluated through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The DPV response currents are linearly dependent on concentrations of xanthine (Xa) in the range 0.10–20 μM, along with a high sensitivity of 6.84 μA μM −1  cm −2 and very low detection limit of 0.006 μM (S/ N  = 3) under the optimal working potential of 0.64 V vs. SCE. Interference experiments show that the nanoenzyme sensor has no obvious responses to most potentially interfering species at a potential of 0.64 V. The fabricated sensor has been applied to the determination of Xa in spiked urine samples with recoveries ranging from 98.26 to 101.4%. Graphical abstract