A multifunctional nanoplatform based on black phosphorus quantum dots (BPQDs) was developed for cancer bioimaging and combined photothermal therapy (PTT) and photodynamic therapy (PDT). BPQDs were functionalized with PEG chains to achieve improved biocompatibility and physiological stability. The as-prepared nanoparticles exhibite prominent near-infrared (NIR) photothermal and red-light-triggered photodynamic properties. The combined therapeutic application of PEGylated BPQDs were then performed in vitro and in vivo. The results demonstrate that the combined phototherapy significantly promote the therapeutic efficacy of cancer treatment in comparison with PTT or PDT alone. BPQDs could also serve as the loading platform for fluorescent molecules, allowing reliable imaging of cancer cells. In addition, the low cytotoxicity and negligible side effects to main organs were observed in toxicity experiments. The theranostic characteristics of PEGylated BPQDs provide an uplifting potential for the future clinical applications.

Different from their bulk counterparts, plasmonic molybdenum oxide nanomaterials display superior optical and electronic properties, but unfortunately, phase-controlled synthesis of molybdenum oxide nanomaterials with multifunctional performances still remains a challenge. To actualize this, a surfactant-free solvothermal strategy was proposed to fabricate molybdenum oxide nanomaterials with a tunable phase. Encouragingly, the as-prepared molybdenum dioxide nanoparticles (MoO2 NPs) exhibit intense near-infrared (NIR) absorption attributed to the localized surface plasmon resonance (LSPR) effect, which results in their application as a surface enhanced Raman scattering (SERS) substrate to detect trace amounts of molecular species including Rhodamine 6G (R6G), crystal violet (CV), IR-780 iodide (IR780) and methylene blue (MB). The detection limit was as low as 5 × 10-8 M and the maximum enhancement factor (EF) was up to 1.10 × 107, compared to other semiconductor nanostructures, the SERS sensitivity may be the best. Meanwhile, with the significant photothermal conversion efficiency up to 61.3%, the plasmonic MoO2 NPs could also be used as a photothermal therapy (PTT) agent for efficient photothermal ablation of cancer cells in vitro.

Oxygen deficient molybdenum oxide (MoO3−x) spurred intense scientific interest in biomedical research owing to the strong localized surface plasmon resonance (LSPR) effect in NIR region.

By means of a simple and photo-induced method, four colors of molybdenum oxide quantum dots (MoOx QDs) have been synthesized for surface-enhanced Raman scattering and photothermal therapy.

Ascribe to the unique two-dimensional planar nanostructure with exceptional physical and chemical properties, black phosphorous (BP) as the emerging inorganic two-dimensional nanomaterial with high biocompatibility and degradability has been becoming one of the most promising materials of great potentials in biomedicine. The exfoliated BP sheets possess ultra-high surface area available for valid bio-conjugation and molecular loading for chemotherapy. Utilizing the intrinsic near-infrared optical absorbance, BP-based photothermal therapy in vivo, photodynamic therapy and biomedical imaging has been realized, achieving unprecedented anti-tumor therapeutic efficacy in animal experiments. Additionally, the BP nanosheets can strongly react with oxygen and water, and finally degrade to non-toxic phosphate and phosphonate in the aqueous solution. This manuscript aimed to summarize the preliminary progresses on theranostic application of BP and its derivatives black phosphorus quantum dots (BPQDs), and discussed the prospects and the state-of-art unsolved critical issues of using BP-based material for theranostic applications.

Research on deep-tissue photothermal therapy (PTT) in the near-infrared II (NIR-II, 1000-1350 nm) region has bloomed in recent years, owing to higher maximum permissible exposure and deeper tissue penetration over that in the near-infrared I (NIR-I, 650-950 nm) region. However, more details need to be uncovered to facilitate a fundamental understanding of NIR-II PTT. Herein, a tumor-targeted therapeutic nanosystem based on NIR-responsive molybdenum oxide (MoO 2) nanoaggregates was fabricated. The photothermal conversion capabilities of MoO 2 in the NIR-I and II regions were investigated step by step, from a simple tissue phantom to a three-dimensional cellular system, and further to a tumor-bearing animal model. NIR-II laser exhibited a lower photothermal attenuation coefficient (0.541 at 1064 nm) in a tissue phantom compared with its counterpart (0.959 at 808 nm), which allows it to be more capable of deeptissue PTT in vitro and in vivo. Depth profile analysis elucidated a negative correlation between the microstructural collapse of tumor tissue and the penetration depth. Moreover, the depth-related tumor ablation was also studied by Raman fingerprint analysis, which demonstrated the major biochemical compositional disturbances in photothermal ablated tumor tissues, providing fundamental knowledge to NIR-II deeptissue photothermal therapy.

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The development of two-dimensional (2D) transition metal dichalcogenides has been in a rapid growth phase for the utilization in surface-enhanced Raman scattering (SERS) analysis. Here, we report a promising 2D transition metal tellurides (TMTs) material, hafnium ditelluride ( HfTe 2 ), as an ultrasensitive platform for Raman identification of trace molecules, which demonstrates extraordinary SERS activity in sensitivity, uniformity, and reproducibility. The highest Raman enhancement factor of 2.32 × 10 6 is attained for a rhodamine 6G molecule through the highly efficient charge transfer process at the interface between the HfTe 2 layered structure and the adsorbed molecules. At the same time, we provide an effective route for large-scale preparation of SERS substrates in practical applications via a facile stripping strategy. Further application of the nanosheets for reliable, rapid, and label-free SERS fingerprint analysis of uric acid molecules, one of the biomarkers associated with gout disease, is performed, which indicates arresting SERS signals with the limits of detection as low as 0.1 mmol/L. The study based on this type of 2D SERS substrate not only reveals the feasibility of applying TMTs to SERS analysis, but also paves the way for nanodiagnostics, especially early marker detection.