In this chapter, the general term “nanoelectrochemistry” is whittled down to the study of conductive surfaces coated with material having one or more external dimensions in the nanoscale. The applications are limited to electrochemical sensors and biosensors modified with nonwoven nanofibrous membranes prepared by electrospinning. Nanofibrous membranes are used to develop biosensors by entrapping reactive molecules, catalysts, or other reactive materials in close proximity to the electrode surface without requiring any physical binding to the electrode. Electrospinning of natural polymers is of great importance due to their implicit potential in foods and the medical sector. Different procedures to prepare conductive nanofibrous membranes are described and applied to the development of flat and flexible electrode sheet; thereby expanding the potential geometries used in electrochemistry. Nanomaterials are especially used to immobilize the recognition elements and improve the transport of the electrical signal from the biorecognition element to the electrode surface.