We present a study of the dynamics of protein aggregation using a common path heterodyne Bloch surface wave label-free sensing scheme. We demonstrate the ability to detect, during thermal incubation, the first early dynamics events of protein aggregation and fibrillogenesis of amyloid- beta peptides, linked to Alzheimer’s Disease. The calibration of the biosensor is made using Lysozyme protein, a well establish protein model system to examine structural and mechanistic principles. The sensor is able to detect the formation of small soluble aggregates at early stages of oligomerisation.