Stability of (bio)functionalized porous aluminum oxide.
Porous aluminum oxide (PAO), a nanostructured support for, among others, culturing microorganisms, was chemically modified in order to attach biomolecules that can selectively interact with target bacteria. We present the first comprehensive study of monolayer-modified PAO using conditions that are relevant to microbial growth with a range of functional groups (carboxylic acid, α-hydroxycarboxylic acid, alkyne, alkene, phosphonic acid, and silane). Their stability was initially assessed in phosphate-buffered saline (pH 7.0) at room temperature. The most stable combination (PAO with phosphonic acids) was further studied over a range of physiological pHs (4-8) and temperatures (up to 80 °C). Varying the pH had no significant effect on the stability, but it gradually decreased with increasing temperature. The stability of phosphonic acid-modified PAO surfaces was shown to depend strongly on the other terminal group of the monolayer structure: in general, hydrophilic monolayers were less stable than hydrophobic monolayers. Finally, an alkyne-terminated PAO surface was reacted with an azide-linked mannose derivative. The resulting mannose-presenting PAO surface showed the clearly increased adherence of a mannose-binding bacterium, Lactobacillus plantarum, and also allowed for bacterial outgrowth.
Laboratory of Organic Chemistry, Wageningen University , Dreijenplein 8, 6703 HB Wageningen, The Netherlands.
Aline
A
Debrassi
Angela
A
Ribbera
Willem M
WM
de Vos
Tom
T
Wennekes
Han
H
Zuilhof
D000475:Alkenes / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry; D000537:Aluminum Oxide / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D057930:Click Chemistry; D004355:Drug Stability; D008954:Models, Biological; D010756:Phosphoric Acids / Q000737:chemistry; D016062:Porosity; D012821:Silanes / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature
D000475:Alkenes; D000480:Alkynes; D002264:Carboxylic Acids; D010756:Phosphoric Acids; D012821:Silanes; C030242:phosphoric acid; D000537:Aluminum Oxide