Phosphonate molecular layers on TiO<sub>2</sub>surfaces

Canepa, Paolo; Solano, Ilaria; Uttiya, Sureeporn; Gemme, G.; Rolandi, R.; Canepa, M.; Cavalleri, Ornella

doi:10.1051/matecconf/20179803001

Cited by 9 publications

(5 citation statements)

References 18 publications

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“…In particular, the P2p BE values detected for all the P‐containing samples (falling in the range 133.2–133.5 eV) are slightly lower than those reported for the single BP molecule [39] . This is ascribable to the coordination of the phosphonate moieties on the superficial Zr atoms as observed also for similar systems [40] . These experimental findings once more attest the desired functionalization of the ZrNPs.…”

Section: Resultssupporting

confidence: 57%

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Modification of Amorphous Mesoporous Zirconia Nanoparticles with Bisphosphonic Acids: A Straightforward Approach for Tailoring the Surface Properties of the Nanoparticles

Scarso

Hossain

Florean

et al. 2021

Chemistry A European J

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The use of readily prepared bisphosphonic acids obtained in few steps through a thio‐Michael addition of commercially available thiols on tetraethyl vinylidenebisphosphonate enables the straightforward surface modification of amorphous mesoporous zirconia nanoparticles. Simple stirring of the zirconia nanoparticles in a buffered aqueous solution of the proper bisphosphonic acid leads to the surface functionalization of the nanoparticles with different kinds of functional groups, charge and hydrophobic properties. Formation of both chemisorbed and physisorbed layers of the bisphosphonic acid take place, observing after extensive washing a grafting density of 1.1 molecules/nm2 with negligible release in neutral or acidic pH conditions, demonstrating stronger loading compared to monophosphonate derivatives. The modified nanoparticles were characterized by IR, XPS, ζ‐potential analysis to investigate the loading of the bisphosphonic acid, FE‐SEM to investigate the size and morphologies of the nanoparticles and 31P and 1H MAS NMR to investigate the coordination motif of the phosphonate units on the surface. All these analytical techniques demonstrated the strong affinity of the bisphosphonic moiety for the Zr(IV) metal centers. The functionalization with bisphosphonic acids represents a straightforward covalent approach for tailoring the superficial properties of zirconia nanoparticles, much straightforward compared the classic use of trisalkoxysilane or trichlorosilane reagents typically employed for the functionalization of silica and metal oxide nanoparticles. Extension of the use of bisphosphonates to other metal oxide nanoparticles is advisable.

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Section: Resultssupporting

confidence: 57%

“… [39] This is ascribable to the coordination of the phosphonate moieties on the superficial Zr atoms as observed also for similar systems. [40] These experimental findings once more attest the desired functionalization of the ZrNPs. In Figure 10 the detail XPS spectrum of P2p band for ZrNPs‐ 1 a sample is reported.…”

Section: Resultsmentioning

confidence: 77%

Modification of Amorphous Mesoporous Zirconia Nanoparticles with Bisphosphonic Acids: A Straightforward Approach for Tailoring the Surface Properties of the Nanoparticles

Scarso

Hossain

Florean

et al. 2021

Chemistry A European J

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“…The O 1s region reported in Figure b can be deconvoluted with four Voigt functions with fwhm = 1.2 eV each. The signal of the TiO 2 substrate, O1, is clearly visible at a binding energy of 529.8 ± 0.2 eV. , Binding of the phosphonate to the substrate is confirmed by the O2 component at 530.8 ± 0.2 eV which can be assigned to the Ti–O–P. ,,− The O3 component at 531.6 ± 0.2 eV has been attributed to some P–OH that has not been covalently bound to the surface but is nevertheless coordinated to the hydroxyl groups present on the substrate surface . The fourth component O4 at 532.6 ± 0.2 eV is mainly due to the unbound PO of the phosphonates , and some adventitious COO – . , The TiOP bridge between the molecules and the substrate is derived from the interaction between the POH groups of the amino-phosphonates with the OH groups of the plasma treated substrate through the condensation of water.…”

Section: Resultsmentioning

confidence: 96%

Anchoring of Aminophosphonates on Titanium Oxide for Biomolecular Coupling

et al. 2019

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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.

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“…XPS measurements were performed using a PHI 5600 Multi-Technique apparatus (55317 Chanhassen, MN, USA) equipped with an X-ray Al-monochromatized source (hν 1486.6 eV), as previously reported [ 34 , 35 ]. The chamber is equipped with a neutralizer (low energy electron flood gun), used to avoid sample charging [ 36 ].…”

Section: Methodsmentioning

confidence: 99%

Biofunctionalization of Porous Titanium Oxide through Amino Acid Coupling for Biomaterial Design

et al. 2023

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Porous transition metal oxides are widely studied as biocompatible materials for the development of prosthetic implants. Resurfacing the oxide to improve the antibacterial properties of the material is still an open issue, as infections remain a major cause of implant failure. We investigated the functionalization of porous titanium oxide obtained by anodic oxidation with amino acids (Leucine) as a first step to couple antimicrobial peptides to the oxide surface. We adopted a two-step molecular deposition process as follows: self-assembly of aminophosphonates to titanium oxide followed by covalent coupling of Fmoc-Leucine to aminophosphonates. Molecular deposition was investigated step-by-step by Atomic Force Microscopy (AFM) and X-ray Photoemission Spectroscopy (XPS). Since the inherent high roughness of porous titanium hampers the analysis of molecular orientation on the surface, we resorted to parallel experiments on flat titanium oxide thin films. AFM nanoshaving experiments on aminophosphonates deposited on flat TiO2 indicate the formation of an aminophosphonate monolayer while angle-resolved XPS analysis gives evidence of the formation of an oriented monolayer exposing the amine groups. The availability of the amine groups at the outer interface of the monolayer was confirmed on both flat and porous substrates by the following successful coupling with Fmoc-Leucine, as indicated by high-resolution XPS analysis.

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Phosphonate molecular layers on TiO₂surfaces

Cited by 9 publications

References 18 publications

Modification of Amorphous Mesoporous Zirconia Nanoparticles with Bisphosphonic Acids: A Straightforward Approach for Tailoring the Surface Properties of the Nanoparticles

Modification of Amorphous Mesoporous Zirconia Nanoparticles with Bisphosphonic Acids: A Straightforward Approach for Tailoring the Surface Properties of the Nanoparticles

Anchoring of Aminophosphonates on Titanium Oxide for Biomolecular Coupling

Biofunctionalization of Porous Titanium Oxide through Amino Acid Coupling for Biomaterial Design

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Phosphonate molecular layers on TiO2surfaces

Cited by 9 publications

References 18 publications

Modification of Amorphous Mesoporous Zirconia Nanoparticles with Bisphosphonic Acids: A Straightforward Approach for Tailoring the Surface Properties of the Nanoparticles

Modification of Amorphous Mesoporous Zirconia Nanoparticles with Bisphosphonic Acids: A Straightforward Approach for Tailoring the Surface Properties of the Nanoparticles

Anchoring of Aminophosphonates on Titanium Oxide for Biomolecular Coupling

Biofunctionalization of Porous Titanium Oxide through Amino Acid Coupling for Biomaterial Design

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Phosphonate molecular layers on TiO₂surfaces