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Characterization of Nanometer-Thick Organic Layers Functionalized Nanoparticles using Ambient Ionization Mass Spectrometry
S. Reddy, C. Schmidt, C. Stephan
PerkinElmer, CA
Keywords: functionalized nanoparticles, characterization of capping agent, permeation enhancer
Summary:
Since the last few decades, the use of nanomaterials as vehicles to transport drugs of interest to specific regions of the body, has been explored. Characterization of the modified nanomaterials is needed for improvement in quality control assessment and process efficiency. We used ambient ionization mass spectrometry as way to characterize the surface of the nanomaterials. A PerkinElmer DSA Time-of-flight mass spectrometer (TOF) was used for the analysis. The sample was layered on a steel mesh and then exposed to the source. The organic capped ligands are released from the nanoparticles due to thermo-lability of the covalent bonds. Using accurate mass and isotope profile information provided by the TOF, along with powerful visualization software tools, we were able to confirm the presence of the different types of ligands attached to nanoparticles. Besides just identifying and confirming one type of organic monolayer covalently bound to the nanoparticle, we were also able to identify bilayers wherein, one organic monolayer is covalently modified with a second type of organic ligand. The DSA-TOF was able to screen for the organic ligands and provide semiquantitative information on the amount of ligand attached to the nanoparticles.
