Fe3O4-mediated dielectric sensor using metamaterial-inspired resonators for the NO2 sensing

Detection of low concentrations of gaseous explosive formulations with NOx derivatives has been a demanding challenge, specifically because the hazard is colossal. Change in the dielectric constant of NO2-purged-Fe3O4 nanoparticles is sensed using metamaterial-inspired sensor. The interaction of NO2 with Fe3O4 nanoparticles steadily changes the dielectric properties of these particles, which are sensed by unit cell of complementary split-ring resonator with resonant frequency of 428 MHz. It shows a gradual change in its resonant frequency along with a new signature evolving around 300 MHz, as the incident NOx concentration changes from 0 to 106 ppm. Highly reliable, re-usable, and selective sensor is projected.