Cu2-xSe Nanoparticles Research Articles

“Sunlight-driven catalytic degradation of MB dye and multi-cycle Re-usability analysis of Cu2-xSe nanoparticles”

One of the best ways to remove organic dyes based contaminant from water resources and industrial waste water is the sunlight driven photo-catalytic degradation method. The theme of the present investigation is the photocatalytic degradation of methylene blue (MB) dye using economically produced Cu2-XSe nanoparticles (NPs) catalyst under solar radiations. The Cu2-XSe NPs crystallized in the cubic structural phase with an average crystallite size around 19 nm. The direct band gap was found to be 2.1 eV. The PL spectra and corresponding CIE diagram show the Cu2-xSe NPs emitted yellow color. The SEM micrographs show that the small grains staked over others to form large grains or patches. The FTIR and EDX spectra confirmed the formation of Cu2-XSe NPs. The obtained optimum photocatalytic degradation efficiency for Cu2-XSe NPs is 90.3 %. For first cycle analysis. The pseudo-first order and second order models were used to analyze the kinetic data of Cu2-XSe NPs for varying concentrations. The multiple-cycle degradation analysis by catalyst of MB dye in one day spam for continuous four cycles were also analysed and discussed. The sun light driven multi-cycle catalytic degradation confirms the re-usability of Cu2-xSe NPs for the treatment of industrial waste water and other contaminated water bodies for the survival of aquatic life and for saving environment.

Cu2-xSe@MXene (Ti3C2Tx) 2D layered heterostructure as an anode for high-performance sodium-ion batteries

With a notable focus on developing efficient sodium storage electrode materials, sodium-ion batteries (SIBs) have been identified as a promising contender in the pursuit of high-performing substitutes for lithium-ion batteries. Among varying sodium storage anode materials for SIBs, nonstoichiometric Cu2-xSe exhibits significant promise. This material stands out due to its ultrahigh electrical conductivity and theoretical sodium storage capacity. However, the practical implementation of Cu2-xSe-based anodes in SIBs is significantly impeded by their sluggish electrochemical reaction kinetics and severe pulverization during the repeated charge–discharge cycles. In the current research, we introduce a novel and straightforward methodology for the synthesis of a heterostructured SIBs anode material (Cu2-xSe@Ti3C2Tx), by coupling Cu2-xSe nanoparticles with two-dimensional (2D) layered MXene (Ti3C2Tx). The 2D layered Ti3C2Tx can provide abundant fast Na+ transport pathways, which effectively promote the ion transport kinetics in the composite anode. Moreover, the pulverization of Cu2-xSe can be effectively mitigated due to the interlamellar spatial confinement of the 2D layered MXene matrix. Consequently, the electrochemical performances of the Cu2-xSe-based anode are significantly improved. Concretely, the Cu2-xSe@Ti3C2Tx anodes demonstrate remarkable rate performance (248mAh g−1 at 10.0 A/g), along with commendable cycling stability, exhibiting a capacity retention of 92 % at 5.0 A/g after 750 cycles. A comprehensive assessment of the Cu2-xSe@Ti3C2Tx anode has been conducted by assembling a full SIB alongside a Na3V2(PO4)3 cathode. This comprehensive study underscores the significant potential of Cu2-xSe-based composite materials, positioning it as a promising candidate for future advancements in SIB technology.

MOFs-derived copper selenides nanoparticles implanted in carbon matrix for broadband electromagnetic wave absorption

Selenide-based functional composites materials demonstrated tunable dielectric properties and heterogeneous interface design, which has been widely studied in electromagnetic (EM) wave absorption field. Herein, Metal-organic frameworks (MOFs) derived carbon coating copper selenide (Cu2-XSe@C) composites were successfully fabricated by using the Cu-MOFs as precursor. After reacting with the gaseous Se in the selenization annealing process, the metal host was converted into the Cu2-XSe nanoparticles, where embodied in the carbon matrix transformed from the organic linker. Based on the tunning dielectric property and building heterogeneous interface, MOFs-derived Cu2-XSe@C composites displayed outstanding EM wave absorption performance. Though the conduction loss, interfacial and dipole polarization behaviors, the minimum reflection loss (RLmin) value of Cu2-XSe@C-600 composites reached to −74.3 dB at 11.7 GHz when the thickness is 2.0 mm. The efficient absorption bandwidth (EAB) can be regulated via controlling the applied thickness. When the thickness is 2.3 mm, above-mentioned Cu2-XSe@C-600 got the broadest absorption performance with the EAB of 5.5 GHz from the 7.7–13.2 GHz, covering the whole X-band. Therefore, MOFs-derived selenide-based composites shed a new design strategy for constructing broadband EM wave absorption, especially in radar stealth applications.

Structural Study on the Novel Plasmonic Optical Materials with Copper Selenide Nanoparticles

Background: Semiconductor-doped materials have been treated actively throughout the last decades and continue to be of great interest because of the challenges of the features due to various nanosize effects. Among other semiconductors, copper chalcogenides demonstrate the interesting plasmonic properties in line with quantum confinement effects provided by the size factor. Objective: This study aims to study the structural and optical features of the sol-gel-derived silica glasses with copper selenide nanoparticles, demonstrating the appearance of the plasmonic light absorption in the near IR range. Method: The samples under study were fabricated through an original sol-gel technique, which realized the simultaneous synthesis of copper selenide and sintering of mesoporous silica. The copper selenide glasses were characterized with X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and optical absorption spectroscopy. Results: Formation of nanocrystalline Cu2-xSe particles of the size range from 10 nm through 100-150 nm is established with XRD and TEM techniques. The principal optical properties are presented by the featured absorption in the visible and near-IR ranges. Eg was evaluated for the direct transitions in the range of 2.10-2.36 eV. The plasmonic resonance in the nanoparticles due to increased carrier concentration originated by intrinsic deficiency of Cu2-xSe nanoparticles with variable stoichiometry. Its energy can be controlled by the Cu/Se ratio in the synthesis procedure. Conclusion: The silica sol-gel glasses with copper selenide nanoparticles were fabricated and characterized by XRD and TEM methods, and their optical absorbance spectra were investigated. The principal optical properties are presented by the featured absorption in the visible and near-IR ranges: the steplike proper absorption of the semiconductor particles characterized by Eg and the intense near-IR band is associated with the localized plasmonic resonance in the nanoparticles due to increased carrier concentration.

Temperature-Sensitive Polymer-Driven Nanomotors for Enhanced Tumor Penetration and Photothermal Therapy.

Self-propelled nanomotors possess strong propulsion and penetration abilities, which can increase the efficiency of cellular uptake of nanoparticles and enhance their cytotoxicity against tumor cells, opening a new path for treating major diseases. In this study, the concept of driving nanomotors by alternately stretching and contracting a temperature-sensitive polymer (TS-P) chain is proposed. The TS-Ps are successfully linked to one side of Cu2-xSe@Au (CS@Au) nanoparticles to form a Janus structure, which is designated as Cu2-xSe@Au-polymer (CS@Au-P) nanomotors. Under near-infrared (NIR) light irradiation, Cu2-xSe nanoparticles generate photothermal effects that change the system temperature, triggering the alternation of the TS-P structure to generate a mechanical force that propels the motion of CS@Au-P nanomotors. The nanomotor significantly improved the cellular uptake of nanoparticles and enhanced their penetration and accumulation in tumor. Furthermore, the exceptional photothermal conversion efficiency of CS@Au-P nanomotors suggests their potential as nanomaterials for photothermal therapy (PTT). The prepared material exhibited good biocompatibility and anti-tumor effects both in vivo and in vitro, providing new research insights into the design and application of nanomotors in tumor therapy.

Influence of Surface Chemistry on Metal Deposition Outcomes in Copper Selenide-Based Nanoheterostructure Synthesis.

The use of nanoparticle surface chemistry to direct metal deposition has been well-studied in the modification of metal nanoparticle substrates but is not yet well-established for metal chalcogenide particle substrates, although integration of these particles into nanoheterostructures is of high interest. In this report, we investigate the effect of Cu2-xSe surface chemistry on the morphology of metal deposition on these plasmonic semiconductor nanoparticles. Specifically, we functionalize Cu2-xSe nanoparticles with a suite of 12 different ligands and investigate how different aspects of the ligand structure do or do not impact the morphology and extent of subsequent metal deposition on the Cu2-xSe surface. Surprisingly, our results indicate that the morphology of the resulting metal deposits and the extent of metal deposition onto the existing Cu2-xSe particle substrate are indistinguishable for the majority of ligands tested. An exception to these findings is observed for particles functionalized by quaternary alkylammonium bromides, which exhibit statistically distinct metal deposition patterns compared to all other ligands tested. We hypothesize that this unique behavior is due to a cooperative binding mechanism of the quaternary alkylammonium bromides to the surface of copper selenide. Taken together, these results yield both new strategies for controlling postsynthetic modification of copper selenide nanoparticles and also reveal limitations of surface chemistry-based approaches for this system.

Modulating efficient differentiation of neural stem cells into neurons by using plasmonic nanoparticles and the NIR II irradiation to boost therapy of Parkinson’s disease

Progressive loss of dopaminergic neurons is the primary pathological feature of Parkinson's disease (PD), which causes severe cognitive and motor dysfunction. In this context, transplantation of neural stem cells (NSCs) is the most promising approach to supply new dopaminergic neurons for the treatment of PD, which faces the challenge of precisely controlling the differentiation direction of NSCs. Herein, we report the efficient differentiation of NSCs into neurons boosted by the joint use of Cu2-xSe nanoparticles (CS NPs) with the second near-infrared (NIR-II) laser irradiation. We reveal the mechanism of neuronal differentiation of NSCs and find that the voltage-gated calcium channels (VGCC) of NSCs can be opened under the stimulation of CS NPs and NIR-II laser irradiation to trigger Ca2+/CaMK/CREB/c-Fos signaling pathway, which promotes the neural differentiation and survival. More importantly, when a mixture of CS NPs and NSCs was injected into the damaged striatum of 6-hydroxydopamine(6-OHDA)-induced PD mice and then irradiated with an external 1064 nm NIR-II laser, the NSCs were efficiently differentiated into dopaminergic neurons to effectively repair the damaged neural circuits in the nigra-striatum and ameliorate the motor disorders and anxiety of PD mice. These findings demonstrate the feasibility and importance of precise modulation of directional differentiation of NSCs into matured functional neurons in vivo and in vitro through advanced functional nanoparticles and nanotechnology, which offers a promising approach for the treatment of PD and other neurodegenerative diseases.

Dual-mode harvest solar energy for photothermal Cu2-xSe biomineralization and seawater desalination by biotic-abiotic hybrid

Biotic-abiotic hybrid photocatalytic system is an innovative strategy to capture solar energy. Diversifying solar energy conversion products and balancing photoelectron generation and transduction are critical to unravel the potential of hybrid photocatalysis. Here, we harvest solar energy in a dual mode for Cu2-xSe nanoparticles biomineralization and seawater desalination by integrating the merits of Shewanella oneidensis MR-1 and biogenic nanoparticles. Photoelectrons generated by extracellular Se0 nanoparticles power Cu2-xSe synthesis through two pathways that either cross the outer membrane to activate periplasmic Cu(II) reduction or are directly delivered into the extracellular space for Cu(I) evolution. Meanwhile, photoelectrons drive periplasmic Cu(II) reduction by reversing MtrABC complexes in S. oneidensis. Moreover, the unique photothermal feature of the as-prepared Cu2-xSe nanoparticles, the natural hydrophilicity, and the linking properties of bacterium offer a convenient way to tailor photothermal membranes for solar water production. This study provides a paradigm for balancing the source and sink of photoelectrons and diversifying solar energy conversion products in biotic-abiotic hybrid platforms.

In situ confined growth of Cu2-xSe nanoparticles in highly defective nitrogen-doped carbon for high-rate sodium-ion battery anodes

Transition metal selenides are considered as hopeful anode materials for sodium-ion battery (SIB) due to the high specific capacity and rich reserves in nature. However, the inherent low conductivity of these anode materials, as well as the inevitable volume expansion and structural collapse during cycling, result in their poor rate performance and cycling stability. Herein, a universal selenization-co-carbonization strategy is proposed to synthesize Cu2-xSe nanoparticles in-situ confined in highly defective nitrogen-doped carbon (Cu2-xSe@NC) with superior architectural features, which involves simultaneous selenization and carbonization procedure of octahedral metal–organic framework (Cu-BTC) precursor. The nitrogen-doped carbon matrix stabilizes/confines the Cu2-xSe nanoparticles to prevent their agglomeration and volume expansion during cycling while endowing high electrical conductivity to the hybrid materials. As anode for SIBs, the Cu2-xSe@NC exhibits a high reversible capacity of 340 mAh/g at 0.1 A/g with a high initial coulombic efficiency of 70 %, superior rate performance (capacity retention of 82.4 % from 0.02 to 5 A/g), and long-cycle durability. The ex-situ XRD and HRTEM techniques confirmed that Cu2-xSe undergoes complex intercalation and crystal evolution accompanied by reversible intermediate phases (NaCuSe and Na2Se) transformation during charge/discharge cycle. First-principles calculations and in-situ EIS confirmed that the intercalation of Na+ can greatly reducing the energy band gap and improving the electrical conductivity of Cu2-xSe@NC, thereby achieving excellent rate performance. Moreover, the Cu2-xSe@NC anode is also evaluated by matching with Na3V2(PO4)3 cathode to assemble a full SIB, which can provide high initial capacity and capacity retention, revealing its potential for practical application.

Antigen Self-Presented Personalized Nanovaccines Boost the Immunotherapy of Highly Invasive and Metastatic Tumors.

Dendritic cell (DC)-based vaccines have shown promise in adoptive cell therapy for enhancing the antigen-specific response of antitumor immunity. However, their clinical efficacy is limited by the less-presented tumor-associated antigens (TAAs) through MHC I and low lymph node homing efficiency. Herein, to address these issues, we rationally design and fabricate DC-based nanovaccines by coating Cu2-xSe nanoparticles (CS NPs) with the membrane of matured DCs (named as DCNV(CSD) nanovaccines). We reveal the important roles of CS NPs in the DCNV(CSD) nanovaccines from three aspects: (1) inducing the immunogenic cell death of tumor cells to expose abundant TAAs; (2) promoting the escape of TAAs from the lysosomes of DCs during the antigen presenting process through MHC I; (3) sustainably releasing traces of copper ions to promote the proliferation of T cells. Our DCNV(CSD) nanovaccines are characterized with high expressions of MHC I, CD80, CD86, CCR7, and ICAM-1 proteins, which not only endow them with abundantly processed specific TAAs, but also a strong capability of homing to the lymph nodes. The homing capability of our small DCNV(CSD) nanovaccines is better than that of matured DCs. More importantly, they can elicit the strong response of potent antispecific CD8+ T cells for antitumor immunotherapy, as tested in the treatment of highly invasive glioblastoma and highly metastatic melanoma. Additionally, DCNV(CSD) nanovaccines can generate memory T cells (TEM) in the spleen of mice to effectively prevent the recurrence of treated tumors. This work demonstrates a universal approach to fabricate high-performance DC-based nanovaccines for tumor immunotherapy by using versatile CS NPs.

Synthesis, structures and DFT study of copper coordination with bis- benzimidazole based thiones and selones: Scope for nonstoichiometric Cu2-xSe nanoparticles

The newly synthesized benzimidazole-based [E2]-donor ligands (E = S or Se) (L1 − L4) on reaction with copper(II) chloride and copper(II) acetate involved reduction of Cu(II) to Cu(I) and yielded copper(I) complexes. The ligands L1 − L3 formed stable 20-membered metallocyclic binuclear Cu(I)-complexes of stoichiometry, [Cu2Cl2(L1-L3)2] (5–7) and [Cu2(OAc)2(L1-L3)2] (9–11). Interestingly, L4 ligand yielded a stable complex, [Cu2Cl2(L4)2] (8) with a chloride anion, but with acetate it formed an unstable complex, [Cu2(OAc)2(L4)2] (12). ESI-mass of coordination compounds 5–12, supported the characteristic molecular ion peaks/fragmented peaks for their ions. NMR study of ligands and complexes, single crystal x-ray crystallography of ligands L1, L2, L4 and complex 6, as well as DFT studies of all ligands and complexes are reported for characterization of ligands and complexes (1–12). Compound 12 with –NCH2CH2OH moiety in the ligand L4 showed very unusual behavior as compared to the compound 11 with –NCH3 moiety in the ligand L3. It degraded under mild conditions to form copper selenide (Cu2-xSe) nanoparticles in the solution, which were characterized using various techniques, such as TEM, SEM and EDX. The plausible mechanism for the instability of the complex 12 even at low temperature (at 0 °C), leading to the formation of Cu2-xSe nanoparticles, has been discussed in this paper.

NIR-II light triggered burst-release cascade nanoreactor for precise cancer chemotherapy

The current strategy of co-delivering copper ions and disulfiram (DSF) to generate cytotoxic CuET faces limitations in achieving rapid and substantial CuET production, specifically in tumor lesions. To overcome this challenge, we introduce a novel burst-release cascade reactor composed of phase change materials (PCMs) encapsulating ultrasmall Cu2-xSe nanoparticles (NPs) and DSF (DSF/Cu2-xSe@PCM). Once triggered by second near-infrared (NIR-II) light irradiation, the reactor swiftly releases Cu2-xSe NPs and DSF, enabling catalytic reactions that lead to the rapid and massive production of Cu2-xSe-ET complexes, thereby achieving in situ chemotherapy. The mechanism of the burst reaction is due to the unique properties of ultrasmall Cu2-xSe NPs, including their small size, multiple defects, and high surface activity. These characteristics allow DSF to be directly reduced and chelated on the surface defect sites of Cu2-xSe, forming Cu2-xSe-ET complexes without the need for copper ion release. Additionally, Cu2-xSe-ET has demonstrated a similar (to CuET) anti-tumor activity through increased autophagy, but with even greater potency due to its unique two-dimensional-like structure. The light-triggered cascade of interlocking reactions, coupled with in situ explosive generation of tumor-suppressive substances mediated by the size and valence of Cu2-xSe, presents a promising approach for the development of innovative nanoplatforms in the field of precise tumor chemotherapy.

Colorimetric evaluation of total antioxidant capacity based on peroxidase-like nonstoichiometric Cu2-xSe nanoparticles

Antioxidants can help trap and neutralize free reactive oxygen species to reduce their damage. Thus, it is important to evaluate the content of antioxidants in foods and drugs. In this paper, a simple and sensitive colorimetric sensing platform for total antioxidant capacity (TAC) detection was developed based on the peroxidase-like nanozyme of nonstoichiometric copper selenide nanoparticles (Cu2-xSe NPs). The Cu2−xSe NPs with copper vacancy structures can accelerate intramolecular charge transfer and effectively catalyze the oxidation of chromogenic substrate colorless 3,3′5,5′-tetramethylbenzidine (TMB) into blue oxidized TMB (oxTMB), exhibiting that they had good peroxidase-like activity. Base on the good activity of Cu2−xSe NPs peroxidase mimics, a colorimetric sensing array combining UV–vis spectrometer, naked eye and smartphone-based digital image analysis for three typical antioxidant acids (ascorbic acid (AA), gallic acid (GA) and citric acid (CA)) were realized and the platform was successfully used for evaluating the TAC in the medical tablets, beverages and fruit juices.

Plasmonic Cu2-xSe Mediated Colorimetric/Photothermal Dual-Readout Detection of Glutathione.

Plasmonic nanomaterials have attracted great attention in the field of catalysis and sensing for their outstanding electrical and optical properties. Here, a representative type of nonstoichiometric Cu2-xSe nanoparticles with typical near-infrared (NIR) localized surface plasma resonance (LSPR) properties originating from their copper deficiency was applied to catalyze the oxidation of colorless TMB into their blue product in the presence of H2O2, indicating they had good peroxidase-like activity. However, glutathione (GSH) inhibited the catalytic oxidation of TMB, as it can consume the reactive oxygen species. Meanwhile, it can induce the reduction of Cu(II) in Cu2-xSe, resulting in a decrease in the degree of copper deficiency, which can lead to a reduction in the LSPR. Therefore, the catalytic ability and photothermal responses of Cu2-xSe were decreased. Thus, in our work, a colorimetric/photothermal dual-readout array was developed for the detection of GSH. The linear calibration for GSH concentration was in the range of 1-50 μM with the LOD as 0.13 μM and 50-800 μM with the LOD as 39.27 μM. To evaluate the practicability of the assay, tomatoes and cucumbers were selected as real samples, and good recoveries indicated that the developed assay had great potential in real applications.

Plasmonic scattering imaging of single Cu2-xSe nanoparticle for Hg2+ detection

The development of new efficient contrast nanoprobe has been greatly concerned in the field of scattering imaging for sensitive and accurate detection of trace analytes. In this work, the non-stoichiometric Cu2-xSe nanoparticle with typical localized surface plasmon resonance (LSPR) properties originating from their copper deficiency as a plasmonic scattering imaging probe was developed for sensitive and selective detection of Hg2+ under dark-field microscopy. Hg2+ can compete with Cu(I)/Cu(II) which were sources of optically active holes coexisting in these Cu2-xSe nanoparticles for its higher affinity with Se2−. The plasmonic properties of Cu2-xSe were adjusted effectively. Thus, the color scattering images of Cu2-xSe nanoparticles was changed from blue to cyan, and the scattering intensity was obviously enhanced with the dark-field microscopy. There was a linear relationship between the scattering intensity enhancement and the Hg2+ concentration in the range of 10–300 nM with a low detection limit of 1.07 nM. The proposed method has good potential for Hg2+ detection in the actual water samples. This work provides a new perspective on applying new plasmonic imaging probe for the reliable determination of trace heavy metal substances in the environment at a single particle level.

Simultaneous Elimination of Reactive Oxygen Species and Activation of Nrf2 by Ultrasmall Nanoparticles to Relieve Acute Kidney Injury.

Excess reactive oxygen species (ROS) can induce serious acute kidney injury (AKI) to result in numerous deaths annually in clinical practice. Elimination of excess ROS by advanced nanotechnology is a very promising AKI therapy. In this Article, we report that PVP-stabilized and quercetin-functionalized ultrasmall Cu2-xSe nanoparticles (abbreviated as CSPQ NPs) can efficiently scavenge ROS and increase the expression of intracellular antioxidative enzymes by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) protein, which drastically alleviates the cellular oxidative stress. Our ultrasmall nanoparticles exhibit excellent biocompatibility. They can be rapidly accumulated into the injured kidney to simultaneously eliminate ROS and activate Nrf2 to improve the renal function. This work demonstrates the great potential of simultaneous elimination of ROS and activation of intracellular Nrf2 in treatment of AKI. It also highlights the potential of CSPQ NPs in protection and prevention of AKI.

Formation and Transformation of Cu2-xSe1-yTey Nanoparticles Synthesized by Tellurium Anion Exchange of Copper Selenide.

Ion exchange reactions of colloidal nanoparticles post-synthetically modify the composition while maintaining the morphology and crystal structure and therefore are important for tuning properties and producing otherwise inaccessible and/or metastable materials. Reactions involving anion exchange of metal chalcogenides are particularly interesting, as they involve the replacement of the sublattice that defines the structure while also requiring high temperatures that can be disruptive. Here, we show that the tellurium anion exchange of weissite Cu2-xSe nanoparticles using a trioctylphosphine-tellurium complex (TOP═Te) yields weissite Cu2-xSe1-yTey solid solutions, rather than complete exchange to weissite Cu2-xTe, with compositions that are tunable based on the amount of TOP═Te used. Upon storage at room temperature in either solvent or air, tellurium-rich Cu2-xSe1-yTey solid solution nanoparticles transform, over the span of several days, to a selenium-rich Cu2-xSe1-yTey composition. The tellurium that is expelled from the solid solution during this process migrates to the surface and forms a tellurium oxide shell, which correlates with the onset of particle agglomeration due to the change in surface chemistry. Collectively, this study demonstrates tunable composition during tellurium anion exchange of copper selenide nanoparticles along with unusual post-exchange reactivity that transforms the composition, surface chemistry, and colloidal dispersibility due to the apparent metastable nature of the solid solution product.

Hollow Cu2-xSe-based nanocatalysts for combined photothermal and chemodynamic therapy in the second near-infrared window.

Chemodynamic therapy (CDT) and photothermal therapy (PTT) have gained popularity due to their non-invasive characteristics and satisfying therapeutic expectations. A Cu-based nanomaterial serving as a Fenton-like nanocatalyst for CDT together with a photothermal agent for simultaneous PTT seems to be a powerful strategy. In this work, the morphological effect of Cu2-xSe nanoparticles on CDT and PTT was systematically investigated. In particular, the hollow octahedral Cu2-xSe nanoparticles exhibited higher photothermal and chemodynamic performance than that of spherical or cubic Cu2-xSe nanoparticles in the second near-infrared (NIR-II) window. In addition, the octahedral Cu2-xSe nanoparticles were further loaded with the autophagy inhibitor chloroquine (CQ) and connected with the targeting neuropeptide Y ligand, and shown to work as a novel therapeutic platform (Cu2-xSe@CQ@NPY), holding an immense potential to achieve synergetic enhancement of CDT/PTT with a positive therapeutic outcome for breast cancer.

Multimetallic post-synthetic modifications of copper selenide nanoparticles.

In this report, we investigate the addition of two metal cations, simultaneously and sequentially to Cu2-xSe nanoparticles. The metal combinations (Ag-Au, Ag-Pt, Hg-Au and Hg-Pt) are chosen such that one metal adds to the structure via cation exchange and the other adds to the structure via metal deposition when added individually to Cu2-xSe nanoparticles. Surprisingly, we find that for each metal combination, across all three synthesis routes, cation exchange and metal deposition products are obtained without deviation from the outcomes seen in the binary metal systems. However, within those outcomes the data show several types of heterogeneities in the morphologies formed including extent and composition of cation exchange products as well as the extent and composition of the metal deposited products. Taken together, these results suggest a hierarchical control for nanoheterostructure morphologies where the pathways of cation exchange or metal deposition in post-synthetic modification of Cu2-xSe exhibit relatively general outcomes as a function of metal, regardless of synthetic approach or metal combination. However, the detailed composition and interface populations of the resulting materials are more sensitive to both metal identities and synthetic procedure (e.g. order of reagent addition), suggesting that certain principles of metal chalcogenide post-synthetic modification are excitingly robust, while also revealing new avenues for both mechanistic discovery and structural control.

Boosting the therapy of glutamine-addiction glioblastoma by combining glutamine metabolism therapy with photo-enhanced chemodynamic therapy.

The complete treatment of high grade invasive glioblastoma (GBM) remains to be a great challenge, and it is of great importance to develop innovative therapeutic approaches. Herein, we found that GBM derived from U87 MG cells is a glutamine-addiction tumor, and jointly using glutamine-starvation therapy and photo-enhanced chemodynamic therapy (CDT) can significantly boost its therapy. We rationally fabricated tumor cell membrane coated Cu2-xSe nanoparticles (CS NPs) and an inhibitor of glutamine metabolism (Purpurin) for combined therapy, because glutamine rather than glucose plays a crucial role in the proliferation and growth of GBM cells, and serves as a precursor for the synthesis of glutathione (GSH). The resultant CS-P@CM NPs can be specifically delivered to the tumor site to inhibit glutamine metabolism in tumor cells, suppress tumor intracellular GSH, and increase H2O2 content, which benefit the CDT catalyzed by CS NPs. The cascade reaction can be further enhanced by irradiation with the second near-infrared (NIR-II) light at the maximum concentration of H2O2, which can be monitored by photoacoustic imaging. The NIR-II light irradiation can generate a large amount of reactive oxygen species (ROS) within a short time to kill tumor cells and enhance the CDT efficacy. This is the first work on the treatment of orthotopic malignant GBM through combined glutamine metabolism therapy and photo-enhanced CDT, and provides insights into the treatment of other solid tumors by modulating the metabolism of tumor cells.