We demonstrate a novel biosensor for in vitro observation of cell membrane behaviors associated with proteins, adapting a supported lipid bilayer (SLB) that mimics the cellular membrane and using label-free surface plasmon resonance spectroscopy (SPRS). In this study, we focus on the detection of membrane behaviors by the specific types of Cu/Zn-superoxide dismutase (SOD1) species, which have been implicated in the neurodegenerative disease. The biomimetic sensor chip was fabricated by the fusion of unilamellar lipid vesicles on a hydrophilic Au surface for SPRS. After injection of several protein samples, the degradation signal of lipid membrane for specific type of protein species was real-time monitored by SPRS. This sensor allows one to observe in vitro the membrane damage due to the protein aggregations, and, importantly, to further develop biomarkers for injured cells.