Perspectives for quantum interference with biomolecules and biomolecular clusters

Abstract

Modern quantum optics encompasses a wide field of phenomena that are either related to the discrete quantum nature of light, the quantum wave nature of matter or light-matter interactions. We here discuss new perspectives for quantum optics with biological nanoparticles. We focus in particular on the prospects of matter-wave interferometry with amino acids, nucleotides, polypeptides or DNA strands. We motivate the challenge of preparing these objects in a 'biomimetic' environment and argue that hydrated molecular beam sources are promising tools for quantum-assisted metrology. The method exploits the high sensitivity of matter-wave interference fringes to dephasing and shifts in the presence of external perturbations to access and determine molecular properties.

Tailoring the volatility and stability of oligopeptides

“…In recent years, substantial research effort has been dedicated to evaluate, understand and explore the effects and benefits of fluorination in biochemistry, medicine and pharmacology . Studying fluoroalkyl derivatized molecules in the gas phase with an increasing number of hydration layers shall soon allow to systematically study the change of their electro‐optical properties in quantum interferometry experiments . Furthermore, it allows the preservation of native N―H functionality and thereby investigation of intramolecular interactions which might well reflect those of native peptides in the absence of solvent or other molecules …”

“…Here, we aim at preparing neutral continuous beams of peptides at low velocity as required for spectroscopy, deflectometry and quantum interferometry or even nanostructuring using soft‐landing of individual biomolecules on surfaces. Even though one may argue that biomolecules are most naturally studied in an aqueous environment, it is meaningful to start from isolated species to which one may later add an increasing number of water molecules to compare their physical data with quantum chemical models . Additionally, gas phase studies of biomolecules enable the elucidation of intrinsic folding preferences without interference of solvents or other molecules …”

“…To suppress fragmentation, one may reduce the heating time or add collisional cooling, once the molecules are airborne. Both ideas have been earlier explored for biomolecules injected into supersonic noble gas jets . This way, neutral intact macromolecules can be volatilized, but at the expense of being 300–1000 m/s fast, depending on the gas type and temperature.…”

“…Even though one may argue that biomolecules are most naturally studied in an aqueous environment, it is meaningful to start from isolated species to which one may later add an increasing number of water molecules to compare their physical data with quantum chemical models. [42,43] Additionally, gas phase studies of biomolecules enable the elucidation of intrinsic folding preferences without interference of solvents or other molecules. [44][45][46][47] While some biomolecules or biomolecular moietiessuch as nucleobases and some vitaminscan be readily sublimated or evaporated [48] oligopeptides, proteins and oligonucleotides will rather fragment than fly when heated.…”

“…Both ideas have been earlier explored for biomolecules injected into supersonic noble gas jets. [43,49,50] This way, neutral intact macromolecules can be volatilized, but at the expense of being 300-1000 m/s fast, depending on the gas type and temperature. In contrast, velocities down to several 10 m/s have been achieved in buffer gas cooled sources [51] for molecules up to stilbene or using laser-induced acoustic desorption even for molecules beyond 10 0 000 amu.…”