Mapping out the aqueous surface chemistry of metal oxide nanocrystals; carboxylate, phosphonate and catecholate ligands

Data underlying the figures in the publication “Mapping out the aqueous surface chemistry of metal oxide nanocrystals; carboxylate, phosphonate and catecholate ligands”, published in JACS Au.

Table of contents:

The .pxp documents contain the experimental data of the figures in the manuscript and it can be opened/edited with the software IGOR Pro 8.0 or higher.

1. Figure 1.pxp: Experimental data for Figure 1. (A) Solvothermal synthesis of HfO₂ nanocrystals starting from 1 equivalent Hf(O-tBu)₄ and 80 equivalents benzyl alcohol. (B) ¹H NMR spectra (normal or diffusion filtered) of MEEAA functionalized HfO₂ NCs in different solvents. The α and β resonances belong to the residual hydroxyl and methyl groups of methanol, respectively. (C) Transmission Electron Microscopy (TEM) image of the synthesized HfO₂ NCs. The NC diameter of the quasi-spherical NCs was calculated after measuring the surface area of at least 150 NCs and calculated the diameter as if it was a circle. A size distribution histogram and a zoomed-in image of a singular NC can be seen respectively in the bottom left and the top right corner.

2. Figure 2.pxp: Experimental data for Figure 2. (A) Ligand exchange performed between MEEAA functionalized NCs and PA-PEG. (B) ¹H NMR reference spectra in MeOD of the free ligands as reference and the stepwise titration of MEEAA functionalized NCs with PA-PEG, equivalents are with respect to the total amount of MEEAA present. (C) ³¹P NMR spectra (4096 scans) in MeOD for the stepwise titration of MEEAA functionalized NCs with PA-PEG, broadened signals are indicative of NC binding. (D) Diffusion filtered ¹H NMR spectra of MEEAA functionalized NCs in MeOD after addition of 1.3 equivalents of PA-PEG. Signals arising from bound MEEAA are denoted in red, signals arising from PA-PEG are denoted in striped blue. CNC = 1210 µmol.L^-1, corresponding to 34 mg NCs of this size in 0.5 ml MeOD. Resonances denoted as * are unidentified impurities.

3. Figure 3.pxp: Experimental data for Figure 3. Diffusion filtered ¹H NMR spectrum of the NC suspension in MeOD at 1.3 equivalents PA-hex-PEG added.

4. Figure 4.pxp: Experimental data for Figure 4. (A) and (B) ³¹P NMR spectra of PA-PEG and PA-hex-PEG functionalized NCs at different D₂O volume %. (C) Free ligand fraction for PA-PEG and PA-hex-PEG at different D₂O volume %, determined by peak deconvolution.

5. Figure 5.pxp: Experimental data for Figure 5. (A) Ligand exchange performed between MEEAA functionalized NCs and nitrodopamine-mPEG. (B) ¹H NMR spectra before and after the ligand exchange titration performed in D₂O with nitrodopamine-mPEG. 1.5 equivalents of nitrodopamine-mPEG were added and the pH was kept above 5 at all times during addition, the purified nitrodopamine functionalized NC spectrum was measured at pH = 7.4. CNC = 128 µmol.L^-1, corresponding to 14.4 mg NCs of this size in 2 ml D₂O.

6. Figure 6.pxp: Experimental data for Figure 6. Effect of pH on ligand binding and stability in water for purified NCs functionalized with PA-PEG, PA-hex-PEG and nitrodopamine-mPEG. (A) Bound and unbound ligand fraction in D₂O based on NMR peak deconvolution at different pH values. (B) Z-average value of NCs in DLS at different pH values. (C) Zeta potential of the NCs at different pH values. All measurements were performed at constant ionic strength (0.01 mol.L^-1 NaCl) at 25°C

7. Figure 7.pxp: Experimental data for Figure 7. Stability of functionalized NCs in different concentrations of phosphate buffered saline (PBS) at pH 7.4 and 25°C. (A) Colloidal stability of functionalized nanocrystals measured using DLS z-average values at different PBS concentrations. (B) Stability of functionalized NCs in 2X PBS over time at pH 7.4 and 25°C.

8. Figure 9.pxp: Experimental data for Figure 9. UV-VIS spectra of purified nitrodopamine-mPEG functionalized NCs at different pH values in H2O.