Immobilisation of β-cyclodextrin on glass: characterisation and application for cholesterol reduction from milk.

β-Cyclodextrin (β-CD) was converted into β-CD-N3 by chemical modification and subsequently attached covalently on glass surface by click reaction. Functionalised glass surface was characterised by static water contact angle and X-ray photoelectron spectroscopy (XPS). Both techniques show that β-CD was successfully attached on glass surface. β-CD on solid surface was used to make a complexation with cholesterol to remove it from milk. 69±1% cholesterol was reduced in 4 h at 25°C and 170 rpm. The same surface was used repeatedly for eight cycles and it maintained its efficiency, with 68±2% cholesterol reduction. Modified glass surface showed almost no degradation as confirmed from XPS analysis after eight cycles of repeated use in cholesterol reduction experiments. The high efficiency and stability of functional monolayer was attributed to its specific structure with relatively low number of functional groups and longer spacer chain length to providing higher flexibility to β-CD molecules.