Molecular sensitised probe for amino acid recognition within peptide sequences

authored by
Xu Wu, Bogdana Borca, Suman Sen, Sebastian Koslowski, Sabine Abb, Daniel Pablo Rosenblatt, Aurelio Gallardo, Jesús I. Mendieta-Moreno, Matyas Nachtigall, Pavel Jelinek, Stephan Rauschenbach, Klaus Kern, Uta Schlickum

The combination of low-temperature scanning tunnelling microscopy with a mass-selective electro-spray ion-beam deposition established the investigation of large biomolecules at nanometer and sub-nanometer scale. Due to complex architecture and conformational freedom, however, the chemical identification of building blocks of these biopolymers often relies on the presence of markers, extensive simulations, or is not possible at all. Here, we present a molecular probe-sensitisation approach addressing the identification of a specific amino acid within different peptides. A selective intermolecular interaction between the sensitiser attached at the tip-apex and the target amino acid on the surface induces an enhanced tunnelling conductance of one specific spectral feature, which can be mapped in spectroscopic imaging. Density functional theory calculations suggest a mechanism that relies on conformational changes of the sensitiser that are accompanied by local charge redistributions in the tunnelling junction, which, in turn, lower the tunnelling barrier at that specific part of the peptide.

External Organisation(s)
Max Planck Institute for Solid State Research (MPI-FKF)
Beijing Institute of Technology
Technische Universität Braunschweig
Institut de Physique des Materiaux, Bucarest-Magurele
Czech Academy of Sciences
Charles University
University of Oxford
École polytechnique fédérale de Lausanne (EPFL)
Nature Communications
Publication date
Publication status
Peer reviewed
ASJC Scopus subject areas
Chemistry(all), Biochemistry, Genetics and Molecular Biology(all), Physics and Astronomy(all)
Electronic version(s) (Access: Open)