Highly sensitive photodetection even approaching the single-photon level is critical to many important applications. Graphene-based hybrid phototransistors are particularly promising for high-sensitivity photodetection because they have high photoconductive gain due to the high mobility of graphene. Given their remarkable optoelectronic properties and solution-based processing, colloidal quantum dots (QDs) have been preferentially used to fabricate graphene-based hybrid phototransistors. However, the resulting QD/graphene hybrid phototransistors face the challenge of extending the photodetection into the technologically important mid-infrared (MIR) region. Here, we demonstrate the highly sensitive MIR photodetection of QD/graphene hybrid phototransistors by using plasmonic silicon (Si) QDs doped with boron (B). The localized surface plasmon resonance (LSPR) of B-doped Si QDs enhances the MIR absorption of graphene. The electron-transition-based optical absorption of B-doped Si QDs in the ultraviolet (UV) to near-infrared (NIR) region additionally leads to photogating for graphene. The resulting UV-to-MIR ultrabroadband photodetection of our QD/graphene hybrid phototransistors features ultrahigh responsivity (up to ∼10 A/W), gain (up to ∼10), and specific detectivity (up to ∼10 Jones).

The development of highly efficient, multifunctional, and biocompatible sonosensitizer is still a priority for current sonodynamic therapy (SDT). Herein, a defect‐rich Ti‐based metal–organic framework (MOF) (D‐MOF(Ti)) with greatly improved sonosensitizing effect is simply constructed and used for enhanced SDT. Compared with the commonly used sonosensitizer TiO2, D‐MOF(Ti) results in a superior reactive oxygen species (ROS) yield under ultrasound (US) irradiation due to its narrow bandgap, which principally improves the US‐triggered electron–hole separation. Meanwhile, due to the existence of Ti3+ ions, D‐MOF(Ti) also exhibits a high level of Fenton‐like activity to enable chemodynamic therapy. Particularly, US as the excitation source of SDT can simultaneously enhance the Fenton‐like reaction to achieve remarkably synergistic outcomes for oncotherapy. More importantly, D‐MOF(Ti) can be degraded and metabolized out of the body after completion of its therapeutic functions without off‐target toxicity. Overall, this work identifies a novel Ti‐familial sonosensitizer harboring great potential for synergistic sonodynamic and chemodynamic cancer therapy.

Hydrogen (H2) therapy is a highly promising strategy against several diseases due to its inherent biosafety. However, the current H2 treatment modalities rely predominantly on the systemic administration of the gas, resulting in poor targeting and utilization. Furthermore, although H2 has significant anti-tumor effects, the underlying mechanisms have not yet been elucidated. Due to their ultrasmall size, nanomaterials are highly suitable drug-delivery systems with a myriad of biomedical applications. Nanocarrier-mediated H2 delivery, as well as in situ production of H2 by nanogenerators, can significantly improve targeted accumulation of the gas and accelerate the therapeutic effects. In addition, nanomaterials can be further modified to enhance passive or active accumulation at the target site. In this Perspective, we summarize the mechanism of H2 therapy and describe possibilities for combining H2 therapy with nanomaterials. We also discuss the current challenges of H2 therapy and provide some insights into this burgeoning field.