Multishell Au@Ag@SiO2 nanorods embedded into a molecularly imprinted polymer as electrochemical sensing platform for quantification of theobromine
- 28 April 2020
- journal article
- research article
- Published by Springer Science and Business Media LLC in Microchimica Acta
- Vol. 187 (5), 1-11
- https://doi.org/10.1007/s00604-020-04288-6
Abstract
A highly uniform and monodisperse silica-encapsulated Au@Ag multilayered core-shell nanorods (similar to 80 nm in length) has been prepared with excellent electrocatalytic properties. Using the Au@Ag@SiO2 nanoassemblies to substantially enhance the sensitivity and the sol-gel molecularly imprinted polymer (MIP) with imprinted cavities to present special molecular recognition sites, a novel electrochemical sensing platform was rationally designed, fabricated, and tested for efficient theobromine (THB) quantification. The formation of final Au@Ag@SiO2@MIP was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The performance of the Au@Ag@SiO2@MIP modified electrode was evaluated by differential pulse voltammetry with the changes in peak current of hexacyanoferrate redox probe measured at a working potential of 0.2 V (vs. saturated calomel electrode) as determination signal. Under optimal conditions, the quantitation of THB was attained in a broad linear range from 10 nM to 100 mu M with a detection limit of 8.0 nM. The selectivity of Au@Ag@SiO2@MIP was examined according to its recognition to THB and the interferents. Finally, the sensing platform was successfully applied to extract and determine THB from food, biological, and environmental samples with acceptable recoveries (92.20-107.1%) and relative standard deviation < 4%. The propsed sensor provides a robust means for monitoring alkaloids in complex matrices and a promising opportunity to develop sensitive and selective electrode materials with good reusability. Graphical abstractThis publication has 33 references indexed in Scilit:
- Simultaneous determination of caffeine, theophylline and theobromine in food samples by a kinetic spectrophotometric methodFood Chemistry, 2013
- Simultaneous quantification of caffeine and its three primary metabolites in rat plasma by liquid chromatography–tandem mass spectrometryFood Chemistry, 2013
- Health Benefits of Methylxanthines in Cacao and ChocolateNutrients, 2013
- Highly monodisperse rattle-structured nanomaterials with gold nanorod core–mesoporous silica shell as drug delivery vehicles and nanoreactorsNanoscale, 2012
- Fabrication of nanoporous Cu–Pt(Pd) core/shell structure by galvanic replacement and its application in electrocatalysisACS Applied Materials & Interfaces, 2011
- Nanocrystal-Based Time-Temperature IndicatorsChemistry – A European Journal, 2009
- Seeded High Yield Synthesis of Short Au Nanorods in Aqueous SolutionLangmuir, 2004
- Silicon dioxide coating of CeO2 nanoparticles by solid state reaction at room temperatureMaterials Research Bulletin, 2002
- Methylxanthines: Toxicity to humans. 3. Theobromine, paraxanthine and the combined effects of methylxanthinesFood and Chemical Toxicology, 1988
- General expression of the linear potential sweep voltammogram in the case of diffusionless electrochemical systemsJournal of Electroanalytical Chemistry and Interfacial Electrochemistry, 1979