Bonnie J Tyler oral presentation (PB2-Thu3-2-2)
Comparison of Cluster Ion Laser-SNMS and ToF-SIMS for 2D and 3D Imaging of Organic and Biological Systems
University of Münster - Physikalisches Institut, Wilhelm-Klemm Str 10, 48149 Münster, Germany
The introduction of commercial large-argon-gas-cluster-ion sputter sources has enabled routine molecular depth profiling and 3D imaging of organic materials with ToF-SIMS. 3D molecular imaging has been demonstrated for a wide variety of organic and biological systems. Despite these advances, sensitivity and quantitation continue to limit applications of the technique for many important systems such as pharmaceuticals. Laser post-ionization of sputtered neutral species is one potential solution to the problems of both low sensitivity and matrix effects.
In this work, we have compared ToF-SIMS and Laser-SNMS for 3D imaging of several organic systems, including biological samples1, pharmaceuticals2 and polymeric materials3. Laser post-ionization was performed using a 157 nm excimer laser. Sample analysis and sputtering were performed using combinations of Bi3+ and Arn+ ions. The figures below show results from a Laser-SNMS 3D image of a sirolimus/probucol dual drug eluting stent. When compared to ToF-SIMS results, Laser-SNMS reduced topographic artefacts and provided better contrast between the two drug
ToF-SIMS and Laser-SNMS show complementary strengths. For high intensity ion signals, ToF-SIMS allows for faster data acquisition. Laser-SNMS, on the other hand, reduces artefacts from topography and matrix effects and enhances measurement efficiency. Higher efficiency reduces the amount of matter that must be sputtered to obtain a given signal, which facilitates measurement of lower concentrations with higher ultimate spatial resolution.
 Nees, R.; Pelster, A.; Körsgen, M.; Jungnickel, H.; Luch, A.; Galla, H.-J.; Arlinghaus, H. F. Biointerphases 2016, 11, 02A305.
 Pelster, A.; Tyler, B. J.; Körsgen, M.; Kassenböhmer, R.; Peterson, R. E.; Stöver, M.; Unger, W. E.; Arlinghaus, H. F. Biointerphases 2016, 11, 041001.
 Pelster, A.; Körsgen, M.; Kurosawa, T.; Morita, H.; Arlinghaus, H. F. Analytical Chemistry 2016, 88, 9638.