This minireview looks at the latest trends in the use of nanoparticles (NPs) in electrochemical biosensing systems. It includes electrochemical characterization of NPs for use as labels in affinity biosensors and other applications. DNA analysis involving NPs is one of the most important topics of current research in bionanotechnology. The advantages of the use of NPs in designing novel electrochemical sensors for DNA analysis are reviewed. Electrochemical NPs can also be used in designing immunoassays, offering the possibility of easy, low cost and simultaneous detection of several proteins. Research into NP applications in electrochemical analysis is in its infancy. Several aspects related to sensitivity as well integration of all the assay steps into a single one need to be improved.