Electrospray Ion Beam Deposition of Proteins, Peptides, and Sugars: Macromolecular Structure Revealed by STM

Stephan Rauschenbach

Max-Planck-Institute for Solid State Research, DE-70569 Stuttgart, Germany

Measuring and understanding the complexity that arises when synthetic or natural, molecular nanostructures interact with their environment are a current challenge of nanoscale science and technology. High-resolution microscopy methods such as scanning probe microscopy or electron microscopy have the capacity to investigate nanoscale systems with ultimate precision, for which, however, atomic scale precise preparation methods of surface science are a necessity. Often however, ultrahigh vacuum surface science and biological molecules are incompatible. Preparative mass spectrometry (pMS) with soft ionization sources links the world of large, biological molecules and surface science, enabling atomic scale chemical control of molecular deposition in ultrahigh vacuum.

In this talk I explore the application of high-resolution scanning probe microscopy to the characterization of structure and properties of large molecules at surfaces. I briefly introduce the fundamental principles of the combined experiments electrospray ion beam deposition. Examples for the deposition and investigation of single particles, for layer and film growth, and for the investigation of structure, conformation, and electronic properties of individual nonvolatile molecules are presented.

They show that our methodology offers a highly controlled and pure path to high resolution microscopy with unique features of the deposition due to the use of charged polyatomic particles. This new field is an enormous sandbox for researching novel, sequence controlled molecular materials and large, individual molecules.

[1] S. Rauschenbach, M. Ternes, L. Harnau & K. Kern: Mass Spectrometry as a Preparative Tool for the Surface Science of Large Molecules. Annu. Rev. Anal. Chem. 9 (2016) pg 16.1–16.26