In this work we explore how our rationally designed peptide amphiphiles bind onto lipid monolayers using neutron reflection combined with deuterium labelling to the lipids, peptides and water. In the home work so far, we have developed lipid monolayer models mimicking mammalian and bacteria (G-, G+) outer cell membranes. To start this part of study, we propose to study how the G4 peptide bind to single and binary component monolayer models to understand how charges and saturation and membrane composition affect the amount of peptide binding and the extent of insertion. The careful use of isotopic contrasts will allow us to analyse the structures using the kenematic approach. 5 days of Surf beam time is requested to complete the tasks as proposed. This work will provide direct molecular insight of peptide selectivity to different membranes.