Ultrafast Spin-Polarized Neural Transduction via Bi₂Se₃-Ti₃C₂Tₓ Quantum-Bio Bridges

Spinal cord injury disrupts neural signal transmission across long lesion gaps that cannot be bridged using passive electrical or biomaterial approaches. This work presents a computational model of an active quantum-enabled neural interface termed the Bio-Quantum Bridge. The system combines Bi2Se3 topological insulator nanoparticles, which generate spin-polarized photocurrents via the circular photogalvanic effect under femtosecond laser excitation, with Ti3C2Tx MXene conductive scaffolds for low-loss signal transport. A validated multiscale numerical framework simulates optical excitation, quantum transduction, mesoscopic transport, and Hodgkin-Huxley neuronal activation. Results predict reliable neural firing and functional signal delivery across distances up to 20 mm, significantly outperforming native tissue transport. The model defines safe operating regimes and provides a theoretical foundation for quantum-active neural repair strategies.