Magneto-stress-electric-coupled biosensors originated in magnetostrictive effect for sensitization

The stress-electric coupling based on receptor functionalization provides a new paradigm for biosensor development. However, it is difficult to avoid the gravity factor of the sensitive element since it can suppress biosensor sensitivity. Herein, a magnetic-sensitization sensing system based on multi-physical field coupling of stress, magnetism, and electricity is proposed to improve the sensitivity of surface stress biosensor. The gravitational interference of sensitive film is eliminated by the magnetostriction of TbDyFe under a magnetic field, amplifying the surface stress-induced film deformation. The urine protein and sugar detections associated with kidney disease serve as a proof of concept revealing the improved sensitivity. The calculated limits of detection (LODs) of urine protein and sugar are 0.21 ng/mL and 0.45 nM, respectively. The LODs are significantly lower than those of traditional surface stress biosensors without magnetic coupling, showing consistency with previous simulation and performance analysis. Furthermore, the urine protein and sugar in clinical samples are accurately detected, showing good practicability of the prepared biosensor. All these results indicate that magneto-stress-electric coupling in magnetostrictive effect contributes to the enhanced performance of surface stress biosensor and provides a platform for highly sensitive detection of clinical biomarkers.