Dual-Terminal Ion-Modulation Multiplier-Based Ion-Doped Stacked Semiconducting Nanosheets for Multifunctional Biomedical Applications.

Stacked semiconducting nanosheets (SSNs), which feature strong in-plane covalent bonds but weak van der Waals (vdWs) interactions between adjacent layers, hold substantial promise in next-generation, printable, and flexible devices. Among them, SSN-based transistors with high current multiplication offer significant potential for large-area, high-integration electronics and biomedical applications. However, the three-terminal configuration of the transistor inevitably increases the process step and power unit. Here, we demonstrate a dual-terminal ion modulation multiplier (IMM) based on ion-doped SSNs, which was obtained through a solution-processed and cost-effective method. We observed an ion-induced self-multiplication effect occurring in the IMM, which significantly enhanced the sensing performance, particularly in thermal sensing. The IMM thermal sensor exhibited a high resolution of 0.02 K and ultrahigh sensitivity of ∼27%/K, more than 7 times higher than that of ion-type thermal sensors. By combining the enhanced operational stability of IMMs, we successfully developed a dual-channel stretchable respiratory sensor (dSRS) based on IMMs, capable of real-time monitoring of subnasal respiratory signals. The dSRS effectively distinguished normal, rapid, and deep breathing states while accurately detecting abnormal respiration, including apnea and hypopnea. Utilizing the unique properties of IMMs, we developed a monolithically integrated and high-performance IMM glucose sensor with temperature compensation. This IMM glucose sensor demonstrated a high sensitivity of 0.91%/μM, a low detection limit of 100 nM, and a high detection accuracy under temperature interference. Our results clearly demonstrate that IMM devices endow SSNs with promising electrical and sensing capabilities, paving the way for next-generation electronics in the post-Moore era.