Cell membrane being the first line of defence of a complex cell, it forms an important scientific topic to study its encounter with various external entities. Nanoparticles are an important topic because of its applications like drug delivery. On the other hand, pore-forming proteins like listeriolysin O, present in virulent bacteria, bind to target membrane and cause cell lysis. This study aims to use Neutron Reflectivity as a powerful technique to understand the binding profile and penetration of protein/nanoparticles and the resultant modifications in molecular conformation of the different multi-component model cell membranes tuned by differently entropic and charged lipids to control the preferential binding of the charged/uncharged nanoparticles and also understand the cell lysis mechanism of the pore-forming protein LLO.