Title: Understanding structure and dynamics of nano-bio interfaces and liquid surfaces by X-ray scattering

Speaker: Dr. Rajendra Prasad Giri, Institute for Experimental and Applied Physics, Kiel University

Zoom Link: https://zoom.us/j/97162788504?pwd=U29vbFJ1Y0xTRVEvaHQ4b3NEQUlrdz09

Abstract: Nanoparticles (NPs) are widely applied in nanomedicine, disease diagnosis, biosensing application, and environmental research. However, biocompatibility is a great concern and comprehending the molecular interactions between NPs and the first barrier, the biomembranes, is pivotal to understanding the physiological effects of nanomaterials. Here, we experimentally investigated the self-assembly, adsorption, intercalation, and interaction of synthetic and biologically relevant NPs with biomimetic model membranes from in-depth structural description using X-ray scattering and thermodynamic measurements using Langmuir-Blodgett methods. The assessment of NPs-induced cytotoxicity prior to their nanomedical applications, and their impact on human health and environment from the structural changes of the biomembranes will be discussed. Liquids are essential to life as well as to the biomembranes. Liquid surfaces and interfaces host most of the essential biological processes, and chemical reactions important to life which is dynamic. Understanding the structure and dynamics of liquid surfaces is thus extremely important having far reaching fundamental, nanotechnological, and industrial applications. The critical processes, such as thermally induced capillary waves and optically induced electron solvation at the liquid surfaces occur in short timescales, typically, on nanosecond to second. We experimentally elucidated the underlying non-equilibrium physics of these ultrafast processes in atomic spatial resolution. Our recent developments of an optical pump – X-ray probe setup, at the LISA P08 beamline at DESY synchrotron (Germany) utilizing the short ultrafast optical (laser) pulses synchronized with X-ray pulses, which is first of its kind for investigating the liquid surfaces using X-ray scattering technique will be discussed. The results from representative liquid surfaces such as liquid mercury and halide salt solutions will also be discussed.