Simple Plasma Test Based on a MoSe₂ SERS Platform for the Specific Diagnosis of Alzheimer's Disease

As a significant Alzheimer's disease (AD)-specific biomarker, the examination of brain-derived tau (BD-tau) is significant in terms of the diagnosis and differentiation of neurological disorders. In this research, sea urchin-like MoSe₂ microspheres were synthesized by hydrothermal synthesis, revealing significant SERS activity, and the enhancement factor (EF) reached 1.44 × 10⁷. The remarkable EF was mainly ascribed to the (i) charge transfer between MoSe₂ and MB, (ii) MB molecule's resonance effect, and (iii) molecular enrichment of porous structures. Through an aptamer-antibody sandwich method, we prepared a BD-tau SERS detection platform based on sea urchin-like MoSe₂ microspheres. The liner range was 0.05-200.00 pM with a limit of detection (LOD) as low as 0.028 pM. Besides, the developed detection platform demonstrated excellent selectivity and enabled early diagnosis of AD patients. In general, the MoSe₂ SERS detection platform can well detect the concentration of BD-tau in mouse plasma samples, showing great potential in specific recognition of AD among neurodegenerative diseases.