Recent advances in layer-by-layer strategies for biosensors incorporating metal nanoparticles

• Advances in layer-by-layer (LbL) biosensors based on metal nanoparticles (MeNP).
• Incorporation of MeNP in biosensors leads to superior performance.
• Importance of size, morphology and distribution of MeNP on biosensor activity.
• Analytical parameters and applicability of MeNP/LbL biosensors.

This review focuses on the recent advances in biosensors based on metal nanoparticles (MeNP) incorporated in layer-by-layer (LbL) or self-assembled layers. LbL methodology has been widely used to immobilize biomolecules without affecting their native conformation, and enables at the same time the incorporation of metallic nanomaterials with controlled molecular architecture, in order to improve electronic communication between the biomolecule and the electrode substrate. The methodologies employed for LbL build up will be reported, with depiction of the procedures used to investigate the size, morphology and distribution of the synthesized MeNP. The benefits conveyed by incorporating MeNP into LbL multilayers will be critically examined. Finally, biosensors based on MeNP-LbL architectures will be described and compared, stressing the analytical parameters and applicability to real sample analysis.