A first-principles investigation of bio-ion-induced magnetic modulation in defect-engineered Janus WSSe monolayers: toward quantum neuromorphic health sensing for brain-inspired diagnostics

induces an intermediate partially suppressed state, enabling graded magnetic modulation. The correlation between adsorption height, charge transfer (from Bader analysis), spin density redistribution, and density of states confirms the role of defect-assisted chemisorption in stabilizing non-volatile magnetic states. In contrast, weaker physisorption leads to more volatile magnetic responses. Importantly, the magnetic readout enables a contact-free sensing paradigm, where bio-ionic signatures are transduced into spin-based logic states without direct electrical current flow. Based on these findings, we propose defect-engineered Janus WSSe monolayers as a platform for quantum neuromorphic health sensing. This system can translate ionic imbalances associated with neurological disorders such as Parkinson's disease, epilepsy, and Alzheimer's disease into distinguishable magnetic signals. Overall, this study establishes a theoretical framework for magnetically programmable, bio-ion-responsive neuromorphic sensors based on atomically thin Janus materials.