The sensor comprises a plurality of conducting nanostructures (2) which can transmit an electrical signal captured from the skin or from another part of an organic tissue to a transmitter means (4, 7) for transmitting said signal, wherein said nanostructures adopt a rigid filiform configuration and are connected at one end to a conducting substrate (3) coupled to said transmitter means (4, 7), said nanostructures being operable to penetrate, by their free end, in said organic tissue (6), as needles.