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Synthesis and characterisation of biologically compatible TiO2 nanoparticles.

Cheyne RW, Smith TA, Trembleau L, McLaughlin AC - Nanoscale Res Lett (2011)

Bottom Line: We describe for the first time the synthesis of biocompatible TiO2 nanoparticles containing a functional NH2 group which are easily dispersible in water.The synthesis of water dispersible TiO2 nanoparticles coated with mercaptosuccinic acid is also reported.We show that it is possible to exchange the stearic acid from pre-synthesised fatty acid-coated anatase 5-nm nanoparticles with a range of organic ligands with no change in the size or morphology.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Chemistry Department, University of Aberdeen, AB24 3 UE, UK. a.c.mclaughlin@abdn.ac.uk.

ABSTRACT
We describe for the first time the synthesis of biocompatible TiO2 nanoparticles containing a functional NH2 group which are easily dispersible in water. The synthesis of water dispersible TiO2 nanoparticles coated with mercaptosuccinic acid is also reported. We show that it is possible to exchange the stearic acid from pre-synthesised fatty acid-coated anatase 5-nm nanoparticles with a range of organic ligands with no change in the size or morphology. With further organic functionalisation, these nanoparticles could be used for medical imaging or to carry cytotoxic radionuclides for radioimmunotherapy where ultrasmall nanoparticles will be essential for rapid renal clearance.

No MeSH data available.


Solid-state ATR-FTIR spectra of SA-coated (top) and Asp-coated (bottom) TiO2 nanoparticles.
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Figure 3: Solid-state ATR-FTIR spectra of SA-coated (top) and Asp-coated (bottom) TiO2 nanoparticles.

Mentions: The presence of the various surface coatings were confirmed by Fourier transform infrared spectroscopy (FTIR) and 1H NMR measurements. The spectrum of pure stearic acid shows the C = O stretch vibration at 1,700 cm-1. This band is completely converted into three new bands in the spectrum of stearic acid-coated TiO2 nanoparticles as previously reported [12]. Two different carboxylate binding sites can be identified, a bridging complex (νa = 1,620 cm-1, νs = 1,455 cm-1) and a bidentate complex (νa = 1,521 cm-1, νs = 1455 cm-1). The infrared (IR) spectrum of the Benz-coated nanoparticles (Figure S5 in Additional file 1) shows no evidence of the free acid C = O stretch, and carboxylate peaks are detected at 1,630, 1,513 and 1,411 cm-1, while C = C aromatic stretches are detected at 1,599 and 1,448 cm-1. Upon ligand exchange with Boc-l-aspartic acid and subsequent removal of the Boc group, a change in the IR spectrum is evidenced (Figure 3). The carboxylate peaks shift to 1,506 and 1,410 cm-1, and the C-N stretching vibration is detected at 1,151 cm-1. The N-H bend is detected by the presence of the strong peak at 1,615 cm-1, demonstrating the presence of a primary amine; however, a C = O stretch observable at 1,721 cm-1 suggests that not all of the carboxylate groups are bound to the TiO2 core. Two broad peaks are observed at 3,316 and 3,166 cm-1 which correspond to N-H stretch peaks; the broadness of the peaks suggests H bonding interactions between adjacent molecules. The IR spectra of Benz-, Boc-Gly-, Boc-Asp-, Mercapto- and Gly-coated nanoparticles are displayed in Figure S5 in Additional file 1.


Synthesis and characterisation of biologically compatible TiO2 nanoparticles.

Cheyne RW, Smith TA, Trembleau L, McLaughlin AC - Nanoscale Res Lett (2011)

Solid-state ATR-FTIR spectra of SA-coated (top) and Asp-coated (bottom) TiO2 nanoparticles.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211840&req=5

Figure 3: Solid-state ATR-FTIR spectra of SA-coated (top) and Asp-coated (bottom) TiO2 nanoparticles.
Mentions: The presence of the various surface coatings were confirmed by Fourier transform infrared spectroscopy (FTIR) and 1H NMR measurements. The spectrum of pure stearic acid shows the C = O stretch vibration at 1,700 cm-1. This band is completely converted into three new bands in the spectrum of stearic acid-coated TiO2 nanoparticles as previously reported [12]. Two different carboxylate binding sites can be identified, a bridging complex (νa = 1,620 cm-1, νs = 1,455 cm-1) and a bidentate complex (νa = 1,521 cm-1, νs = 1455 cm-1). The infrared (IR) spectrum of the Benz-coated nanoparticles (Figure S5 in Additional file 1) shows no evidence of the free acid C = O stretch, and carboxylate peaks are detected at 1,630, 1,513 and 1,411 cm-1, while C = C aromatic stretches are detected at 1,599 and 1,448 cm-1. Upon ligand exchange with Boc-l-aspartic acid and subsequent removal of the Boc group, a change in the IR spectrum is evidenced (Figure 3). The carboxylate peaks shift to 1,506 and 1,410 cm-1, and the C-N stretching vibration is detected at 1,151 cm-1. The N-H bend is detected by the presence of the strong peak at 1,615 cm-1, demonstrating the presence of a primary amine; however, a C = O stretch observable at 1,721 cm-1 suggests that not all of the carboxylate groups are bound to the TiO2 core. Two broad peaks are observed at 3,316 and 3,166 cm-1 which correspond to N-H stretch peaks; the broadness of the peaks suggests H bonding interactions between adjacent molecules. The IR spectra of Benz-, Boc-Gly-, Boc-Asp-, Mercapto- and Gly-coated nanoparticles are displayed in Figure S5 in Additional file 1.

Bottom Line: We describe for the first time the synthesis of biocompatible TiO2 nanoparticles containing a functional NH2 group which are easily dispersible in water.The synthesis of water dispersible TiO2 nanoparticles coated with mercaptosuccinic acid is also reported.We show that it is possible to exchange the stearic acid from pre-synthesised fatty acid-coated anatase 5-nm nanoparticles with a range of organic ligands with no change in the size or morphology.

View Article: PubMed Central - HTML - PubMed

Affiliation: The Chemistry Department, University of Aberdeen, AB24 3 UE, UK. a.c.mclaughlin@abdn.ac.uk.

ABSTRACT
We describe for the first time the synthesis of biocompatible TiO2 nanoparticles containing a functional NH2 group which are easily dispersible in water. The synthesis of water dispersible TiO2 nanoparticles coated with mercaptosuccinic acid is also reported. We show that it is possible to exchange the stearic acid from pre-synthesised fatty acid-coated anatase 5-nm nanoparticles with a range of organic ligands with no change in the size or morphology. With further organic functionalisation, these nanoparticles could be used for medical imaging or to carry cytotoxic radionuclides for radioimmunotherapy where ultrasmall nanoparticles will be essential for rapid renal clearance.

No MeSH data available.