Photothermal therapy (PTT) offers many advantages such as high efficiency and minimal invasiveness, but clinical adoption of PTT nanoagents have been stifled by unresolved concerns such as the biodegradability as well as long-term toxicity. Herein, poly (lactic-co-glycolic acid) (PLGA) loaded with black phosphorus quantum dots (BPQDs) is processed by an emulsion method to produce biodegradable BPQDs/PLGA nanospheres. The hydrophobic PLGA not only isolates the interior BPQDs from oxygen and water to enhance the photothermal stability, but also control the degradation rate of the BPQDs. The in vitro and in vivo experiments demonstrate that the BPQDs/PLGA nanospheres have inappreciable toxicity and good biocompatibility, and possess excellent PTT efficiency and tumour targeting ability as evidenced by highly efficient tumour ablation under near infrared (NIR) laser illumination. These BP-based nanospheres combine biodegradability and biocompatibility with high PTT efficiency, thus promising high clinical potential.

A titanium sulfonate ligand is synthesized for surface coordination of black phosphorus (BP). In contrast to serious degradation observed from the bare BP, the BP after surface coordination exhibits excellent stability during dispersion in water and exposure to air for a long period of time, thereby significantly extending the lifetime and spurring broader application of BP.

Millimeter-scale 3D superlattice arrays composed of dense, regular, and vertically aligned gold nanorods are fabricated by evaporative self-assembly. The regular organization of the gold nanorods into a macroscopic superlattice enables the production of a plasmonic substrate with excellent sensitivity and reproducibility, as well as reliability in surface-enhanced Raman scattering. The work bridges the gap between nanoscale materials and macroscopic applications.

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At itanium sulfonate ligand is synthesized for surface coordination of black phosphorus (BP). In contrast to serious degradation observed from the bare BP,the BP after surface coordination exhibits excellent stability during dispersion in water and exposure to air for al ong period of time, therebys ignificantly extending the lifetime and spurring broader application of BP.Atomically thin black phosphorus (BP), an ew member of two-dimensional (2D) materials,h as attracted increasing interest because of its unique electronic and optical properties and promising applications. [1][2][3][4][5][6][7][8][9][10][11][12][13] BP crystals have strong inplane bonds and the weak van der Waals interlayer interaction enables exfoliation into few-layer BP sheets or phosphorene (single-layer BP). [14][15][16][17][18] As am etal-free layered semiconductor,B Ph as thickness-dependent band gaps varying from 0.3 eV for bulk to 2.0 eV for phosphorene. [3] Moreover,B Pw ith high mobility and as izeable band gap is at the electronic intersection of graphene (a zero-gap highmobility 2D material) and semiconducting transition metal dichalcogenides (large-gap low-mobility 2D materials). [2,[19][20][21] These fascinating properties suggest that BP is not only promising in nanoscale electronic devices, [22][23][24][25][26] but also suitable for near-a nd mid-infrared region optoelectronic applications. [27][28][29][30][31] Moreover,BPnanosheets possess excellent photochemical and photothermal properties with potential catalytic and biomedical applications. [11,32] In spite of these promising properties,afundamental obstacle hindering the application of BP is its lack of air-and water-stability. [3] It has been demonstrated that BP is very reactive to oxygen and water under ambient conditions, resulting in compositional and physical changes and consequently considerable degradation in the electronic and optical properties. [10,26,[33][34][35][36] Long-term exposure of BP to humid air or water can even completely etch the materials away.[37] This poses as evere limitation to the adoption of BP in flexible electronics and photoelectronics,a nd its instability in water further limits potential electrochemical and biomedical applications.T herefore,m uch effort has been made to understand the degradation mechanism and to improve the stability of BP. [10,22,[38][39][40][41][42][43] Optical microscopy and atomic force microscopy (AFM) have revealed droplet-like structures on the surface of BP upon exposure to air. [10,37,38] Consequently, capping layers have been developed to encapsulate BP sheets and enhance the air-stability of BP,but oxygen and water may enter through the interfaces causing eventual breakdown. [38] Ther ole of oxygen and water in BP degradation has been studied recently, [42] and it has been shown that degradation of BP under ambient conditions is initiated by contact with oxygen but water does not play aprimary role in the reaction. However,water is capable of removing P x O y from the surface and exposing P 0 to con...

Nanomedicines intergrating both therapy and diagnosis functions provide a promising strategy for anticancer treatment. As novel two-dimensional materials, black phosphorus nanosheets (BPs) possess unique properties for biomedical applications, pratically for photothermal therapy (PTT) of cancer, but their lack of air and water stability may hinder their application. Herein, a covalent functionalization strategy based on Nile Blue (NB) dye via diazonium chemistry is established to modify BPs, not only enhancing the stability of BPs but also rendering BPs via nearinfrared (NIR) fluorescence, forming a novel multifunctional nanomedicine with both PTT and NIR imaging capabilities. In vitro tests demonstrate that the dye-modified BPs (named NB@BPs) have good biocompatibility and exhibit strong PTT and NIR imaging efficiency. In vivo experiments show that the NB@BPs can mark the tumor site with red fluorescence and lead to efficient tumor ablation under NIR irradiation. These results reveal a potential BP-based nanomedicine with multiple functionalities that bode well for anticancer applications.

Black phosphorus nanosheets (BPs) show great potential for various applications including biomedicine, thus their potential side effects and corresponding improvement strategy deserve investigation. Here, in vitro and in vivo biological effects of BPs with and without titanium sulfonate ligand (TiL4) modification are investigated. Compared to bare BPs, BPs with TiL4 modification (TiL4@BPs) can efficiently escape from macrophages uptake, and reduce cytotoxicity and proinflammation. The corresponding mechanisms are also discussed. These findings may not only guide the applications of BPs, but also propose an efficient strategy to further improve the biocompatibility of BPs.

Black phosphorus quantum dots coordinated with a sulfonic ester of the titanium ligand are prepared and exhibit enhanced stability. In vitro and in vivo photoacoustic imaging applications demonstrate that the quantum dots can efficiently accumulate inside the tumor producing tumor profiles with high spatial resolution, demonstrating their potential as an efficient agent for photoacoustic imaging.