Fabrication of Single-Crystal Violet Phosphorus Flakes For Ultrasensitive Photodetection.

Violet phosphorus (VP) has attracted a lot of attention for its unique physicochemical properties and emerging potential in photoelectronic applications. Although VP has a van der Waals (vdW) structure similar to that of other 2D semiconductors, direct synthesis of VP on a substrate is still challenging. Moreover, optoelectronic devices composed of transfer-free VP flakes have not been demonstrated. Herein, a bismuth-assisted vapor phase transport technique is designed to grow uniform single-crystal VP flakes on the SiO2 /Si substrate directly. The size of the crystalline VP flakes is an order of magnitude larger than that of previous liquid-exfoliated samples. The photodetector fabricated with the VP flakes shows a high responsivity of 12.5 A W-1 and response/recovery time of 3.82/3.03 ms upon exposure to 532 nm light. Furthermore, the photodetector shows a small dark current (<1 pA) that is beneficial to high-sensitivity photodetection. As a result, the detectivity is 1.38 × 1013 Jones that is comparable with that of the vdW p-n heterojunction detector. The results reveal the great potential of VP in optoelectronic devices as well as the CVT technique for the growth of single-crystal semiconductor thin films.

Melamine Polymerization Promotes Compact Phosphorus/Carbon Composite for High-Performance and Safe Lithium Storage.

Phosphorus is regarded as a promising material for high-performance lithium-ion batteries (LIBs) due to its high theoretical capacity, appropriate lithiation potential, and low lithium-ion diffusion barrier. Phosphorus/carbon composites (PC) are engineered to serve as high-capacity high-rate anodes; the interaction between phosphorus and carbon, long-term capacity retention, and safety problems are important issues that must be well addressed simultaneously. Herein, an in situ polymerization approach to fabricate a poly-melamine-hybridized (pMA) phosphorus/carbon composite (pMA-PC) is employed. The pMA hybridization enhances the density and electrical conductivity of the PC, improves the structural integrity, and facilitates stable electron transfer within the pMA-PC composite. Moreover, the pMA-PC composite exhibits efficient adsorption of lithium polysulfides, enabling stable transport of Li+ ions. Therefore, the pMA-PC anode demonstrates a high specific charging capacity of 1,381 mAh g-1 at 10 A g-1, and a great capacity retention of 86.7% at 1 A g-1 over 500 cycles. The synergistic effect of phosphorus and nitrogen further confers excellent flame retardant properties to the pMA-PC anode, including self-extinguishing in 2.5 s, and a much lower combustion temperature than PC. The enhanced capacity and safety performance of pMA-PC show potential in future high-capacity and high-rate LIBs.

Enhanced Catalytic Activity of Crystalline Phosphorus Nanosheets Fabricated via Solvothermal Phase Transformation.

The newly reported crystalline phosphorus nanosheets (cryst-P NSs) exhibit promising features for industrial applications, including outstanding air-water stability and facile large-scale production. However, their complex crystallization impedes a priori tailoring. Herein, the temporal evolution of cryst-P NSs was investigated with the optimized synthesis parameters. The occurrence of self-assembly and solid-state rearrangement unveiled the existence of an intermediate phase as the bulk crystalline precursor and the predominance of nonclassical crystallization pathway(s). With the upgraded synthesis protocol simultaneously strengthening the merits of cryst-P NSs, their catalytic performances were evaluated in various electro- and/or photocatalytic reactions spanning hydrogen and oxygen evolution, full water splitting, CO2 reduction, and organic pollutant decomposition. Superior catalytic activities and orders of magnitude longer lifetimes were consistently discerned compared with the widely employed black phosphorus nanosheets with similar size and thickness. The exciting discoveries in both fundamental crystallization and catalytic applications drastically thrust the comprehension of elemental phosphorus, shedding light on the encouraging capabilities of solvothermal synthesis strategies in the design and systematic tailoring of phosphorus materials.

A black phosphorus nanosheet-based RNA delivery system for prostate cancer therapy by increasing the expression level of tumor suppressor gene PTEN via CeRNA mechanism.

BACKGROUND: Prostate cancer (PCa) has a high incidence in men worldwide, and almost all PCa patients progress to the androgen-independent stage which lacks effective treatment measures. PTENP1, a long non-coding RNA, has been shown to suppress tumor growth through the rescuing of PTEN expression via a competitive endogenous RNA (ceRNA) mechanism. However, PTENP1 was limited to be applied in the treatment of PCa for the reason of rapid enzymatic degradation, poor intracellular uptake, and excessively long base sequence to be synthesized. Considering the unique advantages of artificial nanomaterials in drug loading and transport, black phosphorus (BP) nanosheet was employed as a gene-drug carrier in this study. RESULTS: The sequence of PTENP1 was adopted as a template which was randomly divided into four segments with a length of about 1000 nucleotide bases to synthesize four different RNA fragments as gene drugs, and loaded onto polyethyleneimine (PEI)-modified BP nanosheets to construct BP-PEI@RNA delivery platforms. The RNAs could be effectively delivered into PC3 cells by BP-PEI nanosheets and elevating PTEN expression by competitive binding microRNAs (miRNAs) which target PTEN mRNA, ultimately exerting anti-tumor effects. CONCLUSIONS: Therefore, this study demonstrated that BP-PEI@RNAs is a promising gene therapeutic platform for PCa treatment.

Renaissance of elemental phosphorus materials: properties, synthesis, and applications in sustainable energy and environment.

The polymorphism of phosphorus-based materials has garnered much research interest, and the variable chemical bonding structures give rise to a variety of micro and nanostructures. Among the different types of materials containing phosphorus, elemental phosphorus materials (EPMs) constitute the foundation for the synthesis of related compounds. EPMs are experiencing a renaissance in the post-graphene era, thanks to recent advancements in the scaling-down of black phosphorus, amorphous red phosphorus, violet phosphorus, and fibrous phosphorus and consequently, diverse classes of low-dimensional sheets, ribbons, and dots of EPMs with intriguing properties have been produced. The nanostructured EPMs featuring tunable bandgaps, moderate carrier mobility, and excellent optical absorption have shown great potential in energy conversion, energy storage, and environmental remediation. It is thus important to have a good understanding of the differences and interrelationships among diverse EPMs, their intrinsic physical and chemical properties, the synthesis of specific structures, and the selection of suitable nanostructures of EPMs for particular applications. In this comprehensive review, we aim to provide an in-depth analysis and discussion of the fundamental physicochemical properties, synthesis, and applications of EPMs in the areas of energy conversion, energy storage, and environmental remediation. Our evaluations are based on recent literature on well-established phosphorus allotropes and theoretical predictions of new EPMs. The objective of this review is to enhance our comprehension of the characteristics of EPMs, keep abreast of recent advances, and provide guidance for future research of EPMs in the fields of chemistry and materials science.

Data-Driven Controlled Synthesis of Oriented Quasi-Spherical CsPbBr3 Perovskite Materials.

Controlled synthesis of lead-halide perovskite crystals is challenging yet attractive because of the pivotal role played by the crystal structure and growth conditions in regulating their properties. This study introduces data-driven strategies for the controlled synthesis of oriented quasi-spherical CsPbBr3, alongside an investigation into the synthesis mechanism. High-throughput rapid characterization of absorption spectra and color under ultraviolet illumination was conducted using 23 possible ligands for the synthesis of CsPbBr3 crystals. The links between the absorption spectra slope (difference in the absorbance at 400 nm and 450 nm divided by a wavelength interval of 50 nm) and crystal size were determined through statistical analysis of more than 100 related publications. Big data analysis and machine learning were employed to investigate a total of 688 absorption spectra and 652 color values, revealing correlations between synthesis parameters and properties. Ex situ characterization confirmed successful synthesis of oriented quasi-spherical CsPbBr3 perovskites using polyvinylpyrrolidone and Acacia. Density functional theory calculations highlighted strong adsorption of Acacia on the (110) facet of CsPbBr3. Optical properties of the oriented quasi-spherical perovskites prepared with these data-driven strategies were significantly improved. This study demonstrates that data-driven controlled synthesis facilitates morphology-controlled perovskites with excellent optical properties.

Interfacial Engineering Enables Perovskite Heteroepitaxial Growth on Black Phosphorus for Flexible X-ray Detectors.

2D materials with atomic-scale thickness and mechanical robustness are required for flexible devices. The superior optoelectronic properties and high-Z atoms in metal halide perovskites render them desirable for X-ray detection, but the intrinsic brittleness is an obstacle hampering the applications in flexible detectors. Herein, an interfacial engineering strategy is demonstrated for the epitaxial growth of methylammonium lead bromide (MAPbBr3 ) on black phosphorus (BP) for flexible X-ray detectors. The mechanically robust, high-quality heterostructure consisting of a Pb transition layer is synthesized for the two-way bridging of BP and MAPbBr3 . Excellent optoelectronic properties such as a high X-ray sensitivity of 1,609 ± 122 µC Gy-1  cm-2 (80 times higher than that of the commercial amorphous Se), a fast response time of 40 ± 5 ms, as well as a low detection limit of 3 µGys-1 (about a fifteenth of the medical chest X-ray dose rate) are achieved from the simple and planar direct X-ray detector fabricated on an organic filter membrane. More importantly, these flat and simple devices are bendable and mechanically durable by exhibiting only 10% photocurrent degradation after 200 bending cycles. The novel heterostructure has great potential in large-area, flexible, and sensitive X-ray detection applications.

Whole fresh fruit intake and risk of incident diabetes in different glycemic stages: a nationwide prospective cohort investigation.

PURPOSE: Fruit intake is beneficial to several chronic diseases, but controversial in diabetes. We aimed to investigate prospectively the associations of whole fresh fruit intake with risk of incident type 2 diabetes (T2D) in subjects with different glucose regulation capacities. METHODS: The present study included 79,922 non-diabetic participants aged ≥ 40 years from an ongoing nationwide prospective cohort in China. Baseline fruit intake information was collected by a validated food frequency questionnaire. Plasma HbA1c, fasting and 2 h post-loading glucose levels were measured at both baseline and follow-up examinations. Cox proportional hazards models were used to calculate hazard ratio (HR) and 95% confidence intervals (CI) for incident diabetes among participants with normal glucose tolerance (NGT) and prediabetes, after adjusted for multiple confounders. Restricted cubic spline analysis was applied for dose-response relation. RESULTS: During a median 3.8-year follow-up, 5886 (7.36%) participants developed diabetes. Overall, we identified a linear and dose-dependent inverse association between dietary whole fresh fruit intake and risk of incident T2D. Each 100 g/d higher fruit intake was associated with 2.8% lower risk of diabetes (HR 0.972, 95%CI [0.949-0.996], P = 0.0217), majorly benefiting NGT subjects with 15.2% lower risk (HR 0.848, 95%CI [0.766-0.940], P = 0.0017), while not significant in prediabetes (HR 0.981, 95%CI 0.957-4.005, P = 0.1268). Similarly, the inverse association was present in normoglycemia individuals with a 48.6% lower risk of diabetes when consuming fruits > 7 times/week comparing to those < 1 time/week (HR 0.514, 95% CI [0.368-0.948]), but not in prediabetes (HR 0.883, 95% CI [0.762-1.023]). CONCLUSION: These findings suggest that higher frequency and amount of fresh fruit intake may protect against incident T2D, especially in NGT, but not in prediabetes, highlighting the dietary recommendation of higher fresh fruit consumption to prevent T2D in normoglycemia population.

Biodegradable FePS3 nanoplatform for efficient treatment of osteosarcoma by combination of gene and NIR-II photothermal therapy.

As a common tumor with high incidence, osteosarcoma possesses extremely poor prognosis and high mortality. Improving the survival of osteosarcoma patients is still a great challenge due to the precipice of advancement in treatment. In this study, a combination strategy of gene therapy and photothermal therapy (PTT) is developed for efficient treatment of osteosarcoma. Two-dimensional (2D) FePS3 nanosheets are synthesized and functionalized by poly-L-lysine-PEG-folic acid (PPF) to fabricate a multifunctional nanoplatform (FePS@PPF) for further loading microRNAs inhibitor, miR-19a inhibitor (anti-miR-19a). The photothermal conversion efficiency of FePS@PPF is up to 47.1% under irradiation by 1064 nm laser. In vitro study shows that anti-miR-19a can be efficiently internalized into osteosarcoma cells through the protection and delivery of FePS@PPF nanaocarrier, which induces up-regulation of PTEN protein and down-regulation p-AKT protein. After intravenous injection, the FePS@PPF nanoplatform specifically accumulates to tumor site of osteosarcoma-bearing mice. The in vitro and in vivo investigations reveal that the combined PTT-gene therapy displays most significant tumor ablation compared with monotherapy. More importantly, the good biodegradability promotes FePS@PPF to be cleared from body avoiding potential toxicity of long-term retention. Our work not only develops a combined strategy of NIR-II PTT and gene therapy mediated by anti-miR-19a/FePS@PPF but also provides insights into the design and applications of other nanotherapeutic platforms.

Nucleic Acid Hybridization Enhanced Luminescence for Rapid and Sensitive RNA and DNA Based Diagnostics.

Long-lived emissive nucleic acid probes are widely used in biochemical analysis due to their programmable structures, high signal-to-background ratio, and high sensitivity. Homogeneous detection based on long-lived emissive nucleic acid probes is often achieved through Förster resonance energy transfer (FRET), which suffers from the limitation of a narrow effective distance range. Herein, a new strategy of accessing nucleic acid hybridization-responsive luminescent probes is presented. The photoluminescence (PL) of a Lumi4-Tb complex internally modified with DNA is switched on by nucleic acid hybridization, after which the PL is increased up to 20 times. PL lifetime analysis revealed a possible mechanism of luminescence enhancement. Due to the flexibility of single-stranded nucleic acid chains, the bases and phosphate groups can coordinate with the Tb(III), which reduces the stability of the Tb complex and results in weak PL. After hybridization, the rigid double helix structure suppresses the coordination between Tb(III) and the bases or phosphate groups, causing luminescence enhancement. As the DNA sequence can be freely designed, an array of probes for different DNA or RNA targets can be created with the same Tb complex. Moreover, the novel probe design can afford pM detection limits of DNA or RNA without any nucleic acid amplification and exhibits great potential for nucleic acid detection in clinical diagnosis.

Phosphorus-Based Materials for High-Performance Alkaline Metal Ion Batteries: Progress and Prospect.

Alkaline metal-ion batteries (AIBs) such as lithium-ion batteries (LIBs), sodium-ion batteries (NIBs), and potassium-ion batteries (KIBs) are potential energy storage systems. Currently, although LIBs are widely used in consumer electronics and electric vehicles, the electrochemical performance, safety, and cost of current AIBs are still unable to meet the needs for many future applications, such as large-scale energy storage, due to the low theoretical capacity of cathode/anode materials, flammability of electrolytes and limited Li resources. It is thus imperative to develop new materials to improve the properties of AIBs. Several promising cathodes, anodes, and electrolytes have been developed and among the new battery materials, phosphorus-based (P-based) materials have shown great promise. For example, P and metal phosphide anodes have high theoretical capacity, resource abundance, and environmental friendliness boding well for future high-energy-density AIBs. Besides, phosphate cathode materials have the advantages of low cost, high safety, high voltage, and robust stability, and P-based materials like LiPF6 and lithium phosphorus oxynitride are widely used electrolytes. In this paper, the latest development of P-based materials in AIBs, challenges, effective solutions, and new directions are discussed.

Emerging Synthesis Strategies of 2D MOFs for Electrical Devices and Integrated Circuits.

The development of advanced electronic devices is boosting many aspects of modern technology and industry. The ever-increasing demand for advanced electrical devices and integrated circuits calls for the design of novel materials, with superior properties for the improvement of working performance. In this review, a detailed overview of the synthesis strategies of 2D metal organic frameworks (MOFs) acquiring growing attention is presented, as a basis for expansion of novel key materials in electrical devices and integrated circuits. A framework of controllable synthesis routes to be implanted in the synthesis strategies of 2D materials and MOFs is described. In short, the synthesis methods of 2D MOFs are summarized and discussed in depth followed by the illustrations of promising applications relating to various electrical devices and integrated circuits. It is concluded by outlining how 2D MOFs can be synthesized in a simpler, highly efficient, low-cost, and more environmentally friendly way which can open up their applicable opportunities as key materials in advanced electrical devices and integrated circuits, enabling their use in broad aspects of the society.

Fabricating Black-Phosphorus/Iron-Tetraphosphide Heterostructure via a Solid-Phase Solution-Precipitation Method for High-Performance Nitrogen Reduction.

Although constructing heterostructures is considered as one of the most successful strategies to improve the activity of a catalyst, the heterostructures usually suffer from the cumbersome preparation treatments and low-yield. Inspired by a solid-phase solution-precipitation (SPSP) process, an approach for interface intensive heterostructures with high yield is developed. Herein, a black-phosphorus/iron-tetraphosphide (BP/FeP4 ) heterostructure is prepared mechanochemically with high transient pressure by the solid-phase ball milling approach. The BP/FeP4 heterostructure delivers excellent catalytic performance in the nitrogen reduction reaction (NRR) as exemplified by an NH3 yield of 77.6 µg h-1 mg cat . - 1 \[{\rm{mg}}_{{\rm{cat}}{\rm{.}}}^{{\bm{ - }}1}\] and Faradic efficiency of 62.9% (-0.2 V), which are superior to that of most NRR catalysts recently reported. Experimental investigation and density-functional theory calculation indicate the importance of excess phosphorus in the heterostructures on the NRR activity, which assists the Fe atom to activate N2 via adsorbing the H atom. The results demonstrate the great potential of this new type of heterostructures prepared by the SPSP approach. Benefiting from the simple preparation process and low cost, the heterostructures offer a new insight into the development of highly efficient catalysts.

Carbon Nitride with Rationally Designed π-Conjugated Structure for Bright Blue-Violet Light-Emitting Diodes.

Carbon nitride consisting of the broken π-conjugated structure (bc-CN) is designed as the emitting layer in a blue-violet light emitting diode (LED). The bc-CN is prepared by a metal-oxide (MgO) template-assisted method, in which the low reaction temperature and nano MgO jointly control the degree of polymerization to form cyano groups and broken π-conjugation in the bc-CN nanosheets (bc-CN NS) which emit intense blue-violet photoluminescence at 412 nm. The broken π-conjugated heptazine-ring structure in the bc-CN NS mitigates non-radiation energy loss and promotes the d*-LP transition. As a result, a high quantum efficiency of 73.1% is achieved. The excellent dispersing ability of the bc-CN NS enables solution-based fabrication of the light emitting diode (LED). The LED exhibits intense electroluminescence of 236 cd m-2 at 412 nm with an external quantum efficiency of 0.46%. The broken π-conjugation modulates the optical properties of the polymerized carbon nitride semiconductor giving rise to intense blue-violet electroluminescence, which is very desirable for printable and wide-color-gamut display devices.

Property-Activity Relationship of Black Phosphorus at the Nano-Bio Interface: From Molecules to Organisms.

As a novel member of the two-dimensional nanomaterial family, mono- or few-layer black phosphorus (BP) with direct bandgap and high charge carrier mobility is promising in many applications such as microelectronic devices, photoelectronic devices, energy technologies, and catalysis agents. Due to its benign elemental composition (phosphorus), large surface area, electronic/photonic performances, and chemical/biological activities, BP has also demonstrated a great potential in biomedical applications including biosensing, photothermal/photodynamic therapies, controlled drug releases, and antibacterial uses. The nature of the BP-bio interface is comprised of dynamic contacts between nanomaterials (NMs) and biological systems, where BP and the biological system interact. The physicochemical interactions at the nano-bio interface play a critical role in the biological effects of NMs. In this review, we discuss the interface in the context of BP as a nanomaterial and its unique physicochemical properties that may affect its biological effects. Herein, we comprehensively reviewed the recent studies on the interactions between BP and biomolecules, cells, and animals and summarized various cellular responses, inflammatory/immunological effects, as well as other biological outcomes of BP depending on its own physical properties, exposure routes, and biodistribution. In addition, we also discussed the environmental behaviors and potential risks on environmental organisms of BP. Based on accumulating knowledge on the BP-bio interfaces, this review also summarizes various safer-by-design strategies to change the physicochemical properties including chemical stability and nano-bio interactions, which are critical in tuning the biological behaviors of BP. The better understanding of the biological activity of BP at BP-bio interfaces and corresponding methods to overcome the challenges would promote its future exploration in terms of bringing this new nanomaterial to practical applications.

Detection of coronavirus in environmental surveillance and risk monitoring for pandemic control.

The novel human infectious coronaviruses (CoVs) responsible for severe respiratory syndromes have raised concerns owing to the global public health emergencies they have caused repeatedly over the past two decades. However, the ongoing coronavirus disease 2019 (COVID-19) pandemic induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has received unprecedented attention internationally. Monitoring pathogenic CoVs in environmental compartments has been proposed as a promising strategy in preventing the environmental spread and tracing of infectious diseases, but a lack of reliable and efficient detection techniques is still a significant challenge. Moreover, the lack of information regarding the monitoring methodology may pose a barrier to primary researchers. Here, we provide a systematic introduction focused on the detection of CoVs in various environmental matrices, comprehensively involving methods and techniques of sampling, pretreatment, and analysis. Furthermore, the review addresses the challenges and potential improvements in virus detection techniques for environmental surveillance.

Photothermal and Enhanced Photocatalytic Therapies Conduce to Synergistic Anticancer Phototherapy with Biodegradable Titanium Diselenide Nanosheets.

Nanomaterial-based photothermal and photocatalytic therapies are effective against various types of cancers. However, combining two or more materials is considered necessary to achieve the synergistic anticancer effects of photothermal and photocatalytic therapy, which made the preparation process complicated. Herein, the authors describe simple 2D titanium diselenide (TiSe2 ) nanosheets (NSs) that can couple photothermal therapy with photocatalytic therapy. The TiSe2 NSs are prepared using a liquid exfoliation method. They show a layered structure and possess high photothermal conversion efficiency (65.58%) and good biocompatibility. Notably, upon near-infrared irradiation, these NSs exhibit good photocatalytic properties with enhanced reactive oxygen species generation and H2 O2 decomposition in vitro. They can also achieve high temperatures, with heat improving their catalytic ability to further amplify oxidative stress and glutathione depletion in cancer cells. Furthermore, molecular mechanism studies reveal that the synergistic effects of photothermal and enhanced photocatalytic therapy can simultaneously lead to apoptosis and necrosis in cancer cells via the HSP90/JAK3/NF-κB/IKB-α/Caspase-3 pathway. Systemic exploration reveals that the TiSe2 NSs has an appreciable degradation rate and accumulates passively in tumor tissue, where they facilitate photothermal and photocatalytic effects without obvious toxicity. Their study thus indicates the high potential of biodegradable TiSe2 NSs in synergistic phototherapy for cancer treatment.

From Octahedron Crystals to 2D Silicon Nanosheets: Facet-Selective Cleavage and Biophotonic Applications.

2D silicon nanosheets (SiNSs) are promising materials for biomedicine but facile synthesis of SiNSs remains a challenge. Herein, by means of a sulfur-iodine co-assisted chemical vapor transport method, octahedron silicon (oct-Si) crystals with fully exposed {111} planes are prepared as precursors for efficient synthesis of SiNSs by facet-selective exfoliation. The 13 nm thick SiNSs have good biocompatibility and the sharp Raman scattering signal facilitates intracellular Raman imaging upon exposure to a near-infrared (NIR) laser. Furthermore, the SiNSs have excellent NIR photothermal characteristics such as a large extinction coefficient of 11.3 L g-1 cm-1 and high photothermal conversion efficiency of 21.4% at 1064 nm. In vitro experiments demonstrate superior NIR-II photothermal therapeutic effects in killing cancer cells. Comparing to conventional methods, the novel facet-selective cleavage strategy is more controllable and environmentally friendly boding well for the fabrication of non-van der Waals 2D materials. The multimodal photonic behavior also suggests large potential of the SiNSs pertaining to integrated multi-NIR biophotonic techniques using single nanomaterials.

Biodegradable Bi2 O2 Se Quantum Dots for Photoacoustic Imaging-Guided Cancer Photothermal Therapy.

As new 2D layered nanomaterials, Bi2 O2 Se nanoplates have unique semiconducting properties that can benefit biomedical applications. Herein, a facile top-down approach for the synthesis of Bi2 O2 Se quantum dots (QDs) in a solution is described. The Bi2 O2 Se QDs with a size of 3.8 nm and thickness of 1.9 nm exhibit a high photothermal conversion coefficient of 35.7% and good photothermal stability. In vitro and in vivo assessments demonstrate that the Bi2 O2 Se QDs possess excellent photoacoustic (PA) performance and photothermal therapy (PTT) efficiency. After systemic administration, the Bi2 O2 Se QDs accumulate passively in tumors enabling efficient PA imaging of the entire tumors to facilitate imaging-guided PTT without obvious toxicity. Furthermore, the Bi2 O2 Se QDs which exhibit degradability in aqueous media not only have sufficient stability during in vivo circulation to perform the designed therapeutic functions, but also can be discharged harmlessly from the body afterward. The results reveal the great potential of Bi2 O2 Se QDs as a biodegradable multifunctional agent in medical applications.

Black Phosphorus-Based Multimodal Nanoagent: Showing Targeted Combinatory Therapeutics against Cancer Metastasis.

In breast cancer chemophotothermal therapy, it is a great challenge for the development of multifunctional nanoagents for precision targeting and the effective treatment of tumors, especially for metastasis. Herein, we successfully design and synthesize a multifunctional black phosphorus (BP)-based nanoagent, BP/DTX@PLGA, to address this challenge. In this composite nanoagent, BP quantum dots (BPQDs) are loaded into poly(lactic-co-glycolic acid) (PLGA) with additional conjugation of a chemotherapeutic agent, docetaxel (DTX). The in vivo distribution results demonstrate that BP/DTX@PLGA shows striking tropism for targeting both primary tumors and lung metastatic tumors. Moreover, BP/DTX@PLGA exhibits outstanding controllable chemophotothermal combinatory therapeutics, which dramatically improves the efficacy of photothermal tumor ablation when combined with near-light irradiation. Mechanistically, accelerated DTX release from the nanocomplex upon heating and thermal treatment per se synergistically incurs apoptosis-dependent cell death, resulting in the elimination of lung metastasis. Meanwhile, in vitro and in vivo results further confirm that BP/DTX@PLGA possesses good biocompatibility. This study provides a promising BP-based multimodal nanoagent to constrain cancer metastasis.