Detection of ferritin concentration from blood sample using RF spiral inductor based cavity

In this paper, a novel microwave planar resonant sensor (using two spiral inductors) is designed and developed for detection of ferritin from the blood sample using non destructive technique. Due to concentration change of ferritin in blood, shift in resonant frequency arise. The frequency range of 15 GHz–16 GHz is used as it is effective for label-free analysis of ferritin. The sensor is designed using the full wave electromagnetic solver, HFSS 13.0, and an empirical model is developed for the accurate calculation of ferritin concentration in terms of shifts in the resonant frequency. Due to homogeneous H-field in spacing between two inductors, placement position of ferritin will not affect the sensitivity. Significant frequency shifts as high as 105 MHz, 192 MHz, 310 MHz and 655 MHz are observed for concentrations as low as 20 ng/ml, 50 ng/ml, 100 ng/ml and 320 ng/ml of ferritin respectively. Simulation results suggest that proposed sensor is sensitive even to concentration of 3 ng/ml of sample.