The present invention discloses a nitride based sensor including a nitride based semiconductor, wherein a plurality of metal nanoparticles are attached to a surface of the nitride based semiconductor, and the surface of the nitride based semiconductor is passivated with at least one thiol compound. The present invention also provides a method of fabricating a nitride-based sensor. The present invention also discloses a porous gallium nitride (GaN) based H2 gas sensor, comprising a GaN based semiconductor with a plurality of Pt nanoparticles attached to a surface, wherein the GaN based semiconductor is passivated with a thiol compound, and wherein the sensor exhibits responsiveness of at least 60% for detection of H2 at a concentration of 30 ppm at room temperature.