A novel NEMS radiation sensor optimized for ultrahigh sensitive and isotropic detection of gamma irradiation is presented. The sensor is designed as a 3D symmetrical array of nanostructured platinum nanorod capacitor with 20 to 50 nm silicon oxide dielectric layer and a surface to volume ratio magnified by a factor of 5 × 10 3 to 8 × 10 5 as compared to bulk capacitor electrodes. For wide range gamma radiation doses from 5 to 35 kG using a Co 60 source in the ±90° angle range, the detected sensitivity is evaluated in the range of 800 nf/G compared to 1.1 pf/G for conventional bulk capacitive sensors, a factor of ~ 8 × 10 5 improvement.