Molecular Dynamics of Neurotensin and Lysozyme Soft-Landing on Gold: Influence of the Molecular Projectile Velocity, Incidence Angle and Temperature.

Employing large argon cluster ion beams, the iBEAM technique has exhibited aptitude in transferring large intact biomolecules from a target to a collector surface in the vacuum, e.g., lysozyme and glucose oxidase, while preserving their bioactivity. Our molecular dynamics (MD) simulations described the desorption of intact lysozymes, glucose oxidase, and even lysozyme clusters comprising up to five units, thereby suggesting the potential soft desorption of heavy biomolecules and their molecular clusters. In turn, assuming their soft desorption, the present contribution models the landing of a single neurotensin cluster containing 5 neurotensin molecules or one lysozyme molecule onto a gold substrate using reactive MD. The parameter space, including incidence angle, collision velocity, and cluster/protein temperature, is systematically explored. Our simulations show that fragmentation increases with the rise of the velocity, collision angle toward the normal, and temperature. Also, after the collision, the backscattering phenomenon is predominantly influenced by varying the collision velocity but is less affected by the collision angle and temperature. Nonetheless, all molecular projectile parameters play a role in shaping the landing process on gold.