Enhanced spin-polarization and detection limit in a spin-based optoelectrochemical DNA hybridization sensor induced by circularly polarized light†

We investigate the influence of the correlation between different types of polarized light (linear and circular) and spin-polarization |P_s| (in %) on the effectiveness of a spin-based quantum dot-modified DNA device for a DNA hybridization sensor. The device exhibits a significant two-fold increase in |P_s| (in %) when exposed to circularly polarized (C.P.) light, in comparison to the state of no illumination. This improvement in |P_s| results in a significant ten-fold enhancement in the limit of detection (L.O.D.) of the electrode under C.P. light illumination, surpassing the conditions without illumination and even achieving a two-fold increase compared to linearly polarized (L.P.) light illumination. These results emphasize the crucial significance of polarized light in maximizing the efficiency of spin-based DNA hybridization sensors. The significant enhancements in the performance observed under C.P. light illumination demonstrate the potential use of our device to function as a highly sensitive and efficient tool in spin-based bio-sensing applications.