The interaction of flavonoids with silica surfaces is of interest for separation and recovery of these natural products with potential anti-oxidant and anti-inflammatory properties. The benefit of tailored silica materials for natural product separation is based on the ability to readily tune their surface functionality and pore structure. In this work, the adsorption of quercetin, a model plant-derived flavonoid, was measured on silica particles (450nm diameter) that were non-functionalized, hydrophobically functionalized (16.2mg decyl groups/g) or titania modified (0.33-9.83mg TiO2/g). Quercetin interactions with these functionalized silica particles were interpreted from adsorption measurements on non-porous silica particles, which eliminate the potential diffusional and steric constraints of pores. Titania functionalized particles are found to exhibit significantly increased adsorption capacities compared to non-functionalized and decyl functionalized materials, presumably due to binding of quercetin to the metal oxide, and this capacity increased linearly with surface coverage of titania. The ability to recover the activity of bound quercetin is demonstrated using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. This investigation provides guidelines for the surface modification of both porous and nonporous silica for the recovery of natural product flavonoids, taking advantage of the binding properties of the functionalized silica surface.
|Number of pages||7|
|Journal||Colloids and Surfaces A: Physicochemical and Engineering Aspects|
|State||Published - Aug 5 2015|
Bibliographical noteFunding Information:
This work was supported by the National Science Foundation Integrated Graduate Education and Research Training (IGERT) program on Bioactive Interfaces and Devices (grant # DGE-0653710 ), the University of Kentucky Research Experience for Undergraduates (REU) program # EC-0851716 and a United States Department of Agriculture Biomass Research and Development Initiative (BRDI) grant (award # 2011-10006-30363 ). We would like to thank Eric C. Price for his experimental assistance in lab during his independent study in chemical engineering. We would also like the thank Dr. Kim Anderson for use of her dynamic light scattering particle size analyzer. Thanks to Prachi Gupta and Sundar Prasanth in Dr. Thomas Dziubla's lab at the University of Kentucky for their helpful discussions regarding quercetin, its antioxidant activity and properties in solution.
© 2015 Elsevier B.V.
ASJC Scopus subject areas
- Surfaces and Interfaces
- Physical and Theoretical Chemistry
- Colloid and Surface Chemistry