Single-Molecule Conductance of Intramolecular Hydrogen Bonding in Histamine on Gold

We perform single-molecule conductance measurements and DFT calculations on histamine, a biogenic amine that contains a flexible aliphatic linker and several nitrogen moieties with a potential for hydrogen bonding. Our study determines that junctions containing the free-base form of histamine can bridge through a molecular structure containing an intramolecular hydrogen bond. Conductance of this structure is higher than that through the saturated aliphatic linker. Flicker noise analysis of junction conductance confirms that transport occurs through the hydrogen bond and establishes a benchmark for noise measurements in hydrogen-bonded junctions. Overall, our work provides insights into the formation and conduction of intramolecular hydrogen bonding in single-molecule conductance measurements and into the conformations of the neurotransmitter histamine on noble metal surfaces.

Automated summary

This study investigates the conductance and intramolecular hydrogen bonding of histamine using single-molecule conductance measurements and DFT calculations. The results show that histamine in the free-base form can bridge through a molecular structure with intramolecular hydrogen bonding, resulting in higher conductance than through the saturated aliphatic linker. Flicker noise analysis confirms the transport through hydrogen bonding and provides a benchmark for noise measurements in hydrogen-bonded junctions.