Anchoring of Aminophosphonates on Titanium Oxide for Biomolecular Coupling

Abstract

Aminophosphonates were chosen for a first step functionalization of TiO 2 grown on titanium, as they possess a phosphonate group on one end, that can be exploited for coupling with the oxide surface, and an amino group on the other end to enable further functionalization of the surface. The deposition of aminophosphonates with different chain lengths (6 and 12 methylenes) was investigated. Oxygen plasma treatment proved useful in increasing the number of −OH groups at the TiO 2 surface, thus helping to anchor the aminophosphonates. By combining different surface-sensitive experimental techniques, we found the existence of a discontinuous monolayer where the molecules are covalently coupled to the TiO 2 surface. For the molecules with longer chains, we find evidence of their covalent coupling to the surface through Ti−O−P bond formation, of the exposure of the amino groups at the outer surface, and of an increase in the order of the layer upon thermal annealing.

Bioactive Coatings on Titanium: A Review on Hydroxylation, Self-Assembled Monolayers (SAMs) and Surface Modification Strategies

“…In order to preserve unreacted amino groups to be used in further functionalization, it was essential to perform the annealing process in an inert atmosphere. Indeed, their preliminary studies indicated that unreacted amino groups could be anchored to single amino acids by using aminododecilphosphonic acid [ 88 ].…”

Comparable Studies on Nanoscale Antibacterial Polymer Coatings Based on Different Coating Procedures

“…On one hand, we chose atom transfer radical polymerization (ATRP), a surface polymerization approach leading directly from the monomers to anti-microbially coated titanium surfaces. For comparison purposes, we used a classical route comprising co-polymerization of quaternary ammonium group-containing vinyl benzyl monomeric building blocks with p-vinyl benzyl phosphonate as adhering monomer [76,77]. In both approaches starting from p-vinyl benzyl chloride, two quaternary ammonium salts were prepared with two dimethyl alkylamines of different alkyl length: octylamine and octadecylamine leading to vinyl benzyl dimethyl octyl ammonium chloride (VBCOQ) and vinyl benzyl dimethyl octadecyl ammonium chloride (VBCODQ), respectively.…”

“…In this classical route, the antimicrobial coatings were produced by drop coating the metallic surfaces and the phosphonate monomeric moiety was responsible to attach to the titanium surface. For the drop coating variants, these monomers were polymerized together with a phosphonate [76,77] responsible for binding the co-polymer on Ti surface. The two different coating procedures should lead to two different coating structures on the surface (see Figure 1).…”

Morphological and Mechanical Characterization of DNA SAMs Combining Nanolithography with AFM and Optical Methods

“…In parallel to patterning, nanoshaving experiments can be advantageously employed to measure the thickness of molecular layers down to the subnanometer level, thus allowing monitoring film thickness changes following supramolecular multi-step assembly. At variance with previous reports that used the hard contact mode to displace molecules [ 34 , 39 , 40 , 41 , 42 ], we explore the use of the hard tapping mode to move the AFM tip as a shaver that selectively displaces molecules from the surface [ 43 ].…”