Executive Summary : | Graphene and its derivatives are widely used for sensing applications due to their exceptional optical, electrical, mechanical, electrochemical properties, and bio-molecular adsorption capabilities. However, protein molecules can alter their structure, morphology, and states upon adsorption to the basal plane of graphene, affecting the physical and chemical behavior of the protein molecules on the graphene surface. This study aims to investigate the interaction between protein molecules and the graphene layer, focusing on the Langmuir monolayer (LM) of two graphene derivatives: octadecylamine functionalized graphene (ODA-Gr) and carboxyl functionalized graphene (COOH-Gr) at the air-water (A/W) interface. The amine (-NH2) and carboxyl (-COOH) functionalization of graphene can yield amphiphilicity to the graphene for stabilization as LM at the A/W interface. The study will study the stability, surface phases, and thermodynamical parameters of the LM of ODA-Gr and COOH-Gr at the A/W interface. Three model proteins, bovine serum albumin (BSA), human serum albumin (HSA), histone protein (HP), and two cancer bio-marker proteins (PSA and CEA), will be used to investigate the protein-graphene interaction at the interfaces. From a device perspective, it is crucial to study the interaction of protein molecules with the ultrathin film of graphene on solid substrates. The ultrathin LB films of ODA-Gr and COOH-Gr will be deposited onto quartz wafers, which can act as the active surface area of an electrochemical quartz crystal microbalance (eQCM). The nature of interaction, kinetics, affinity, and specificity towards the ultrathin LB film of the specific graphene derivatives will be assessed from this study. |