This work is based on the analysis and designing of gate all around N+-doped layer nanowire tunnel field-effect transistors (NTFET) without junctions for application in a biosensor by considering the various bio molecules like uricase, proteins, biotin, streptavidin, Aminopropyl-triethoxy-silane (ATS), and many more with dielectric modulation technique and gate-all-around (GAA) environment. Device sensitivity and tunneling probability is further improved by N+ doped layer (1×1020cm-3). The change in the subthreshold-slope (SS), drain current (ID), transconductance(gm), and ratio of ION/IOFF has been examined to detect the sensitivity of the proposed device by confining various biomolecules in the area of nanocavity. The nanocavity area creates a shield in the source gate of oxide layer and electrodes metal. The junctionless GAA-NTFET (JLGAA-NTFET) shows less leakage current and large control on the channel. The design of JLGAA-NTFET is with high doping concentration and observed higher sensitivity for APTS biomolecule which is suitable for sensor design application.