In this contribution we’ll exemplified the usefulness of label free electrochemical biosensors that utilizes nanolayers of glycans and peptides for improved biosensing. Molecular recognition events accompanied by conformational alternation are prone to undergo collective structural change when assembled in monolayers and can be translated to electrical signal. This phenomenon is demonstrated here for ions, small molecules and proteins biosensing. Two cases will be discussed in depth. The first will demonstrate a new method for sensing enzymes based on their protein-protein interactions and not on their biocatalytic activities. We apply this methodology and show a proof of concept for kinases, which are important cancer biomarkers that are conventionally detected based on their catalytic activity. The method we describe here is generic for developing sensitive and specific biosensors and other disease-related enzymes based on their interactions. The second case describes glycan-based sensing of enzymes through their biocatalysis. Sialylation is an enzymatic process in which sialyltransferase (ST) attaches sialic acid to glycans. Sensing enzymatic sialylation is important for evaluating of pathological events and pathogen invasion. We show that the characteristics of a biantennary N–glycan monolayer affect the biosensing of enzymatic sialylation. Desialylation of different complex sialylated N-glycans based biosensors will also be presented in light of their uses in neuraminidase (NA) viral activity and preferences studies.