Giovanni Costantini1

1, University of Warwick, Coventry, , United Kingdom

Understanding the interaction between complex (bio)molecules and inorganic surfaces lies at the heart of a number of fundamental and industrial research areas with applications ranging from healthcare to energy, from food to environmental protection. In particular, the ability to characterise the resulting interfaces at high spatial resolution has been the key to significant advancements in the field and is thus a major investigation topic.
This talk will present recent advances in the use of high-resolution scanning tunnelling microscopy (STM) to analyse a number of (bio)molecule-surface model systems with increasing complexity. It will start from analysing how the two dimensional self-assembly of simple amino acids is already influenced by their conformational flexibility. It will then move onto dipeptides to show that, when interacting with metallic surfaces, these molecules can undergo reactions similar to those catalysed by enzymes with significant consequences for their structure, assembly and chirality. The discussion will then proceed to analyse the limits that standard molecular deposition techniques impose on the size of (bio)molecules that can by studied in surface science. Finally it will be demonstrated that these limitations can be overcome by using soft ionisation techniques capable to transfer thermolabile complex molecules in the gas phase and to soft land them intact onto surfaces under fully controlled depositions conditions. In particular, it will be shown that a combination of electrospray vacuum deposition and high-resolution STM allows the imaging of individual macromolecules with unprecedented detail, thereby unravelling structural and self-assembly characteristics that have so far been impossible to determine.