Fast synthesis, formation mechanism, and control of shell thickness of CuS hollow spheres

Improving Chemotherapy Effectiveness: Utilizing CuS Nanoparticles Coated with AS1411 Aptamer and Chitosan for Targeted Delivery of Doxorubicin to Cancerous Cells

Here, a novel targeted nanostructure complex was designed as an alternative to the traditional treatment approaches for breast cancer. A delivery system utilizing CuS nanoparticles (CuS NPs) was developed for the purpose of targeted administration of doxorubicin (Dox), an anticancer agent. To regulate Dox release, chitosan (CS), a biodegradable and hydrophilic polymer with biocompatible properties, was applied to coat the Dox-loaded CuS NPs. Furthermore, AS1411 aptamer, served as a targeting agent for breast cancer cells (MCF-7 and 4T1 cells), was conjugated with CS-Dox-CuS NPs effectively. To assess the effectiveness of APT-CS-CuS NPs, various methods such as flow cytometry analysis, MTT assay, fluorescence imaging, and in vivo antitumor efficacy were employed. The hollow core and porous surface of CuS NPs improved the Dox loading capacity and entrapment efficiency (almost 100%). The rate of drug release at the tumor site (citrate buffer with pH 5.6) exhibited a marked increase in comparison to that observed within the physiological environment (phosphate buffer with pH 7.4). The targeted formulation (APT-CS-Dox-CuS NPs) significantly increased cytotoxicity of the Dox payload in target cells, including 4T1 (p ≤ 0.0001 (****)) and MCF7 (p ≤ 0.01 (**)) cells compared to CHO cells. Moreover, the ability of tumor growth inhibition of the targeted system was significantly (p ≤ 0.05 (*)) more than free Dox in tumor-bearing mice. The findings indicate that the targeted formulation augmented effectiveness and specificity while minimizing harm to non-targeted cells, signifying its potential as a sophisticated cancer drug delivery system.

Hollow CuS nanoparticles equipped with hydroxyapatite/hyaluronic acid coating for NIR/pH dual-responsive drug delivery

The near-infrared (NIR)/pH dual-responsive nanoplatform shows great potential in remote photothermal therapy for tumor on account of the near-infrared window in biological tissue and the mild acidic environment in tumor cells. CuS nanoplatform has become a rising star in the field of photothermal agents due to its excellent NIR responsiveness and photostability. In this work, hollow CuS nanoparticles with high photothermal conversion efficiency (42.42 %) were synthesized through a novel surfactant micelle-assisted method. Then, CuS@hydroxyapatite (HAP)/hyaluronic acid (HA) nanoclusters with controllable drug release property were prepared by capping HAP and HA on the surface of CuS via electrostatic self-assembly approach. The hollow structure of CuS and the large specific surface area of HAP ensure an outstanding doxorubicin hydrochloride (DOX) loading efficiency of 99.2 % in CuS@HAP/HA nanoclusters. The introduction of HA effectively retards the initial burst release of DOX and ensures the excellent biocompatibility of nanoclusters. More importantly, CuS@HAP/HA displays distinct NIR/pH dual-responsive drug release properties owing to the excellent NIR responsiveness of hollow CuS and the gradual dissolution of HAP under acidic conditions. This work provides an environmentally benign method to prepare CuS-based nanoclusters with excellent NIR/pH responsive drug delivery properties, which has great potential in remote photothermal therapy.

Photothermal-Ionic-Pharmacotherapy of Myocardial Infarction with Enhanced Angiogenesis and Antiapoptosis

Promoting angiogenesis is an effective therapeutic strategy to repair damaged hearts after myocardial infarction (MI). Copper ions and mild heat (41-42 °C) have been shown to promote angiogenesis, but their efficacy in MI is unknown. Here, a multicomponent hydrogel (EDR@PHCuS HG) is developed by encapsulating edaravone (EDR, a free radical scavenger) loaded porous hollow copper sulfide nanoparticles (PHCuS NPs) in a hyaluronic acid hydrogel (HG). Exposed to 808 nm near-infrared (NIR) light irradiation, the EDR@PHCuS HG exhibits controlled copper-ion release and mild photothermal effect to synergistically promote angiogenesis. In addition, released EDR inhibits cardiomyocyte apoptosis to further repair hearts. In the mouse model of MI, treatment with the EDR@PHCuS HG under an 808 nm laser significantly recovers the cardiac function and inhibits ventricular remodeling. This platform elucidates the cardioprotective effects of copper ions and mild heat and will provide a highly efficient treatment for MI.

Core-satellite nanoreactors based on cationic photosensitizer modified hollow CuS nanocage for ROS diffusion enhanced phototherapy of hypoxic tumor

Photodynamic therapy (PDT) efficiency is directly affected by the reactive oxygen species (ROS) generated by photosensitizers. However, ROSs' ultrashort life span and limited diffusion distance restrict the PDT efficiency. Therefore, it is important to control the delivery strategy of photosensitizers for PDT treatment. Herein, the core-satellite nanoreactors were fabricated with oxygen generation and ROS diffusion properties. The hollow CuS encapsulating horseradish peroxidase (HRP) was combined with the cationic photosensitizers (PEI-Ce6). The unique photosensitizers delivery strategy makes the nanoreactors achieve ROS diffusion-enhanced PDT effect. First, HRP in "core" (HRP@CuS) can decompose hydrogen peroxide (H₂O₂) to O₂, increasing O₂ levels on the surface of the nanoreactor. Second, the Ce6 molecules covalent-linked with PEI are uniformly dispersed on the surface of CuS as a "satellite", avoiding Ce6 aggregation and causing more Ce6 molecules be activated to produce more ¹O₂. Due to the Ce6 was on the surface of the CuS nanocages, the generated ROS may ensure a larger diffusion range. Meanwhile, the inherently CuS nanocages exhibit photothermal and photoacoustic (PA) effect. The photothermal effect further enhances the ROS diffusion. Under the guidance of PA imaging, nanoreactors exhibit highly efficient hypoxic tumor ablation via photodynamic and photothermal effect. Overall, the core-satellite nanoreactors provide an effective strategy for tumor therapy, further promoting the research of photosensitizers delivery.

Facile aqueous synthesis of hollow dual plasmonic hetero-nanostructures with tunable optical responses through nanoscale Kirkendall effects

Herein, we report the colloidal synthesis of hollow dual-plasmonic nanoparticles (NPs) using Au@Cu₂O core-shell NPs as templates and exploiting the nanoscale Kirkendall effect. In our synthesis, we used organic compounds as a source of chalcogenide ions for an anion exchange reaction at elevated temperatures using polyvinylpyrrolidone (PVP) as a capping reagent to transform the solid Cu₂O shell into a hollow copper chalcogenide shell. The resulting structures possess different features depending on the chalcogenide precursor employed. TEM images confirm the complete transformation of Au@Cu₂O templates when 1,1-dimethyl-2-selenourea was added and the formation of hollow Au@Cu_2-x Se nanostructures. In contrast, residues of Cu₂O attached to the Au core were present when thioacetamide was used for the synthesis of Au@Cu_2-x S with all other conditions kept the same. The divergence of architectures caused distinct optical properties of Au@Cu_2-x S and Au@Cu_2-x Se NPs. This synthetic approach is an effective pathway for maneuvering the size of interior voids by varying the concentration of chalcogenide ions in the reaction mixture. The insights gained from this work will enrich the synthetic toolbox at the nanoscale and guide us on the rational design of multicomponent plasmonic nanoparticles with precisely controlled hollow interiors and sophisticated geometries, further enhancing our capabilities to fine-tune the electronic, optical, compositional, and physicochemical properties.

GOx-Functionalized Platelet Membranes-Camouflaging Nanoreactors for Enhanced Multimodal Tumor Treatment

Background

Glucose oxidase (GOx)-based starvation therapy is a new cancer treatment strategy. However, the characteristics such as limited curative effect and hypoxic tumor environment hinder its further application seriously.

Methods

Herein, doxorubicin (DOX) loaded in hollow mesoporous copper sulfide (HMCuS) nanoparticles assembled with manganese dioxide (HMMD) as nanoshell was prepared. We developed a targeted enhanced cancer treatment method to camouflage HMMD by GOx-functionalized platelet (PLT) membranes (HMMD@PG).

Results

GOx can be specially transported to the tumor site with PLT membrane for effective starvation treatment. Glucose and oxygen (O₂) in the tumor were converted to H₂O₂ under the catalysis of GOx. HMMD can catalyze H₂O₂ to produce O₂ and consume glutathione (GSH) in time, which regulates the tumor microenvironment (TME) and improves the adverse conditions of anti-tumor. In addition, DOX encapsulated in HMCuS-MnO₂ release was accelerated from the nanoparticles after the “gatekeeper” MnO₂ is consumed. The study of anti-tumor mechanism shows that the remarkable tumor suppressive ability of HMMD@PG comes from the three peaks synergy of starvation treatment, photothermal treatment (PTT), and chemotherapy. This nanoplatform disguised by PLT membrane has significant tumor inhibition ability, good biocompatibility and almost has no side effects in main organs.

Conclusion

This work broadens the application mode of GOx and shows the new development of a multi-mode collaborative processing system of nanoplatforms based on cell membrane camouflage.

Copper sulfide nanostructures: synthesis and biological applications

Over the past few years, considerable attention has been paid to biomedical applications of copper sulfide nanostructures owing to their enhanced physiochemical and pharmacokinetics characteristics in comparison to gold, silver, and carbon nanomaterials. The small-sized Cu x S y nanoparticles have the advantage to absorb efficiently in the near-infrared region (NIR) above 700 nm and the absorption can be tuned by altering their stoichiometries. Moreover, their easy removal through the kidneys overpowers the issue of toxicity caused by many inorganic substances. The low cost and selectivity further add to the advantages of Cu x S y nanostructures as electrode materials in comparison to relatively expensive materials such as silver and gold nanoparticles. This review is mainly focused on the synthesis and biomedical applications of Cu x S y nanostructures. The first part summarizes the various synthetic routes used to produce Cu x S y nanostructures with varying morphologies, while the second part targets the recent progress made in the application of small-sized Cu x S y nanostructures as biosensors, and their analysis and uses in the cure of cancer. Photoacoustic imaging and other cancer treatment applications are discussed. Research on Cu x S y nanostructures will continue to increase over the next few decades, and great opportunities lie ahead for potential biomedical applications of Cu x S y nanostructures.

Versatile precursor-dependent copper sulfide nanoparticles as a multifunctional catalyst for the photocatalytic removal of water pollutants and the synthesis of aromatic aldehydes and NH-triazoles

A series of copper sulfide (CS) nanoparticles (NPs) were synthesized just by varying the amount of the sulfur precursor and have been explored for the first time as a three-way heterogeneous catalyst in the photocatalytic oxidation of a number of aromatic alcohols, photocatalytic degradation and the reduction of water pollutants, and the facile synthesis of pharmaceutically important moiety 4-aryl-NH-1,2,3-triazoles. The green and novel protocol was successfully developed for the synthesis of covellite (CuS, Cu²⁺) and the covellite-villamaninite (CuS-CuS₂) (copper in Cu²⁺, Cu¹⁺) phases of copper sulfide, employing EDTA both as the chelating and capping agent via a simple precipitation method at room temperature using water as the solvent. A blue shift in the absorption spectra and band gap in the range of 2.02-2.07 eV prompted the investigation of the as-synthesized CS nanoparticles as the photocatalyst under visible light irradiation. In the absence of any oxidizing or reducing agent, covellite CuS nanoparticles showed the highest photocatalytic efficiency for the degradation of methylene blue (MB) and the reduction of carcinogenic and mutagenic Cr(vi) to non-toxic Cr(iii). Interestingly, the mixed phase of CS (CuS-CuS₂), where Cu is present in both +1 and +2 oxidation states, was found to be the most efficient catalyst compared to CuS toward the visible light-mediated selective oxidation of various benzyl alcohols to their corresponding aldehydes. However, in the synthesis of substituted NH-1,2,3-triazoles, single-phase CS nanoparticles (i.e., CuS) provided the best catalytic result. This significant outcome certainly opens up the scope for realizing the present demand of low-cost multifunctional semiconductor nano-materials, which will have a huge impact on the economy and environment when they show more than two potential applications.

Copper Phosphide Nanoparticles Used for Combined Photothermal and Photodynamic Tumor Therapy

Copper-based nanomaterials are widely used in near-infrared (NIR) light-mediated deep tumor treatment because of their abundant photothermal and photodynamic properties. However, copper phosphide (Cu₃P) nanoparticles (NPs) are rarely investigated. Herein, Cu₃P NPs were prepared to strengthen their local surface plasmon resonance absorption in the NIR region, exhibiting promising photothermal and photodynamic properties. After surface modification by polyethylene glycol, the formed pCu₃P NPs showed negligible influence on the viability of 4T1 cells, presenting remarkable biocompatibility. However, with 808 nm irradiation, pCu₃P NPs could induce HSP70 and HO-1 protein expression and enhance intracellular reactive oxygen species levels, leading to dramatic cell death. In 4T1 tumor-bearing mice, an intravenous injection of biocompatible pCu₃P NP could lead to remarkable aggregation in the tumor region and significantly inhibit tumor growth under 808 nm laser irradiation, presenting great potential for tumor therapy.

Macrophage-Membrane-Camouflaged Disintegrable and Excretable Nanoconstruct for Deep Tumor Penetration

The consolidation of nanovectors with biological membranes has recently been a subject of interest owing to the prolonged systemic circulation time and delayed clearance by the reticuloendothelial system of such systems. Among the different biomembranes, the macrophage membrane has a similar systemic circulation time, with an additional chemotactic aptitude, targeting integrin proteins. In this study, we aimed to establish a laser-activated, disintegrable, and deeply tumor-penetrative nanoplatform. We used a highly tumor-ablative and laser-responsive disintegrable copper sulfide nanoparticle, loaded it with paclitaxel, and camouflaged it with the macrophage membrane for the fabrication of PTX@CuS@MMNPs. The in vitro paclitaxel release profile was favorable for release in the tumor microenvironment, and the release was accelerated after laser exposure. Cellular internalization was improved by membrane encapsulation. Cellular uptake, cytotoxicity, reactive oxygen species generation, and apoptosis induction of PTX@CuS@MMNPs were further improved upon laser exposure, and boosted permeation was achieved by co-administration of the tumor-penetrating peptide iRGD. In vivo tumor accumulation, tumor inhibition rate, and apoptotic marker expression induced by PTX@CuS@MMNPs were significantly improved by laser irradiation and iRGD co-administration. PTX@CuS@MMNPs induced downregulation of cellular proliferation and angiogenic markers but no significant changes in body weight, survival, or significant toxicities in vital organs after laser exposure, suggesting their biocompatibility. The disintegrability of the nanosystem, accredited to biodegradability, favored efficient elimination from the body. In conclusion, PTX@CuS@MMNPs showed promising traits in combination therapies for excellent tumor eradication.

Mesoporous CuS nanospheres decorated rGO aerogel for high photocatalytic activity towards Cr(VI) and organic pollutants

Mesoporous CuS nanospheres (CuS-NS) decorated reduced graphene oxide (rGO) aerogel composite (3D CuS-NS/rGO) was prepared by chemical reduction process and used for the synergistic removal of Cr(VI) and cationic dyes. The porosity of the as prepared samples was determined by Bruner-Emmet-Teller (BET) surface Area. Structural and morphological properties were studied by Scanning electron microscopy (SEM) and Transmission electron microscope (TEM). These analysis revealed that the as obtained hybrid CuS-NS/rGO composite with three dimensional (3D) structure was composed of mesoporous CuS nanospheres clearly induced onto the interconnected network of rGO sheets. The photocatalytic performance of 3D CuS-NS/rGO composites was studied against the reduction of Cr(VI) and degradation of cationic dyes (MB and RhB) under visible light spectrum. Excellent photocatalytic performance was observed with 3D CuS/rGO hybrid composites as compared to the as prepared CuS nanospheres. This high photocatalytic activity was attributed to the efficient charge transfer from the mesoporous CuS nanospheres to nanosheets of rGO, which was confirmed by UV-Vis spectrometry (UV-Vis). Electrical conductivity of the prepared samples was also investigated using electrochemical impedance spectroscopy (EIS). Additionally, the as prepared hybrid composites was easy to recycle by using simple tweezers and can be a best candidate for industrial applications.

An Efficient Strategy for the Fabrication of CuS as a Highly Excellent and Recyclable Photocatalyst for the Degradation of Organic Dyes

An effective and practical in situ sulfuration approach has been developed in this work, for the fabrication of CuS with a 3D hierarchical network structure under mild preparation conditions. The prepared CuS consists of a primary structure of the multi-structure interchange copper foam precursor, and a secondary structure of nanoplates. The structural characteristics, morphologies, and photocatalytic performances of the prepared photocatalyst were investigated systematically. To evaluate the photocatalytic performance of the prepared CuS samples, we investigated the degradation of MB (methylene blue), RhB (Rhodamine B), and MB/RhB dye solutions over the samples under the irradiation of simulated solar light. Specifically, the degradation of RhB rapidly reached ≈100.0% after simulated solar light irradiation for 25 min, which is higher than those of P25 (83.0%) and bulk CuS (54.8%). For the mixed systems of MB/RhB, both the degradations of MB and RhB reached up to ≈99.0% after simulated solar light irradiation for 25 min. The superior photocatalytic performances of the prepared samples are attributed to the synergistic effects of high optical absorption, large specific surface area, and abundant active sites. The prepared catalysts can retain the photocatalytic activities during the entire reaction process without significant loss after four catalytic cycles, which reveals that the CuS with a stable 3D hierarchical network structure has a promising prospect as an ideal recyclable catalyst.

Nitric Oxide Stimulated Programmable Drug Release of Nanosystem for Multidrug Resistance Cancer Therapy

Nitric oxide (NO) molecular messenger can reverse the multidrug resistance (MDR) effect of cancer cells through reducing P-glycoprotein (P-gp) expression, beneficial for creating a favorable microenvironment for the treatment of doxorubicin (Dox)-resistant cancer cells. Development of sophisticated nanosystems to programmably release NO and Dox becomes an efficient strategy to overcome the MDR obstacles and achieve promising therapeutic effects in Dox-resistant cancer. Herein, a NO stimulated nanosystem was designed to engineer a significant time gap between NO and Dox release, promoting MDR cancer therapy. A o-phenylenediamine-containing lipid that can hydrolyze in response to NO was embedded in the phospholipid bilayer structure of liposome to form NO-responsive liposome, which could further encapsulate l-arginine (l-Arg)/Dox-loaded gold@copper sulfide yolk-shell nanoparticls (_ADAu@CuS YSNPs) to form _ADLAu@CuS YSNPs. Under 808 nm laser irradiation, the unique resonant energy transfer (RET) process and reactive oxygen species (ROS) generation in the confined space of _ADLAu@CuS YSNPs could effectively convert l-Arg into NO, regionally destabilizing the phospholipid bilayer structure, as a result of NO release. However, at this early stage Dox could not be released from YSNPs due to the molecular scaffold limit. As the NO release progressed, the NO-responsive liposome layer was deteriorated more severely, allowing Dox to escape. This NO and Dox sequential release of _ADLAu@CuS YSNPs could significantly inhibit P-gp expression and enhance Dox accumulation in Dox-resistant MCF-7/ADR cells, leading to promising in vitro and in vivo therapeutic effects and presenting their great potential for MDR cancer therapy.

Photodegradable CuS SERS Probes for Intraoperative Residual Tumor Detection, Ablation, and Self-Clearance

Surface-enhanced Raman scattering (SERS) probes have exhibited great potential in biomedical applications. However, currently reported SERS probes are mainly fabricated by nondegradable Au or Ag nanostructures, which are not favorably cleared from the imaged tissues. This bottleneck hinders their in vivo applications. We herein explore a degradable SERS probe consisting of hollow CuS nanoparticles (NPs) to circumvent the current limitation. We identify, for the first time, the Raman enhancement effects of hollow CuS NPs as a SERS probe for Raman imaging of residual tumor lesions. Uniquely, CuS SERS probes are degradable, which stems from laser-induced photothermal effects of CuS NPs, leading to their disintegration from shell structures into individual crystals, thus facilitating their self-clearance from imaged tissues. This novel CuS SERS probe with photodegradation characteristics opens avenues for applying Raman imaging toward a myriad of biomedical applications.

Copper sulfide: An emerging adaptable nanoplatform in cancer theranostics

Copper sulfide nanoparticles (CuS NPs), emerging nanoplatforms with dual diagnostic and therapeutic applications, are being actively investigated in this era of "war on cancer" owing to their versatility and adaptability. This article discusses the pros and cons of using CuS NPs in diagnostics, therapeutics, and theranostics. The first section introduces CuS NPs and discusses the features that render them more advantageous than other established nanoplatforms in cancer management. Subsequent sections include specific in vitro and in vivo results of different studies showing the potential of CuS NPs as nanoplatforms. Methods used for visualization (photoacoustic imaging and magnetic resonance imaging) of CuS NPs and treatment (phototherapy and combinatorial therapy) have also been discussed. Furthermore, the challenges and opportunities associated with using CuS NPs have been elucidated. Further investigations on CuS NPs are required to translate it for clinical applications.

Structure based optical properties and catalytic activities of hydrothermally prepared CuS nanostructures

The nano-sized copper sulfides (CuS) with different morphologies were prepared by hydrothermal method without any surfactant or template. The morphology and structure of CuS were characterized by powder x-ray diffraction (XRD), Fourier transform infrared spectroscopy, x-ray photoelectron spectra (XPS), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET) and ultraviolet-visible (UV-vis) absorption spectroscopy. FESEM results show that four morphologies of CuS (flower-like nanospheres, cross-linked nanodisks, cross-linked nanoplates and nanosheets) were prepared simply by changing the hydrothermal solvent. According to the XPS, XRD and HRTEM results the synthesized nano-sized structures are highly crystallized pure hexagonal covellite CuS. UV-vis spectra results show intense absorption peaks in the visible region, confirming that the resultant CuS has potential application in the field of solar cells. The catalytic activities of resultant CuS on model pollutant methylene blue (MB) in the dark were also investigated in detail. The small and flat crystallites show rapid degradation rate on MB, which is attributed to the numerous active sites on their large specific surface area. The as-synthesized CuS nanosheets took the shortest time (only 15 min) to degrade MB completely compared with the other nanostructural CuS in this work as well as previously reported ones. Total organic carbon removal of the samples approved mineralization of the MB pollutant. Thus, CuS is an excellent catalyst for degrading organic pollutants, which does not require light energy for its catalytic activities.

Resonance Energy Transfer-Promoted Photothermal and Photodynamic Performance of Gold-Copper Sulfide Yolk-Shell Nanoparticles for Chemophototherapy of Cancer

Gold (Au) core@void@copper sulfide (CuS) shell (Au-CuS) yolk-shell nanoparticles (YSNPs) were prepared in the present study for potential chemo-, photothermal, and photodynamic combination therapy, so-called "chemophototherapy". The resonance energy transfer (RET) process was utilized in Au-CuS YSNPs to achieve both enhanced photothermal and photodynamic performance compared with those of CuS hollow nanoparticles (HNPs). A series of Au nanomaterials as cores that had different localized surface plasmon resonance (LSPR) absorption peaks at 520, 700, 808, 860, and 980 nm were embedded in CuS HNPs to screen the most effective Au-CuS YSNPs according to the RET process. Thermoresponsive polymer was fabricated on these YSNPs' surface to allow for controlled drug release. Au₈₀₈-CuS and Au₉₈₀-CuS YSNPs were found capable of inducing the largest temperature elevation and producing the most significant hydroxyl radicals under 808 and 980 nm laser irradiation, respectively, which could accordingly cause the most severe 4T1 cell injury through oxidative stress mechanism. Moreover, doxorubicin-loaded (Dox-loaded) P(NIPAM-co-AM)-coated Au₉₈₀-CuS (p-Au₉₈₀-CuS@Dox) YSNPs could more efficiently kill cells than unloaded particles upon 980 nm laser irradiation. After intravenous administration to 4T1 tumor-bearing mice, p-Au₉₈₀-CuS YSNPs could significantly accumulate in the tumor and effectively inhibit the tumor growth after 980 nm laser irradiation, and p-Au₉₈₀-CuS@Dox YSNPs could further potentiate the inhibition efficiency and exhibit excellent in vivo biocompatibility. Taken together, this study sheds light on the rational design of Au-CuS YSNPs to offer a promising candidate for chemophototherapy.

Rose-like CuS microflowers and their enhanced visible-light photocatalytic performance

Surfactant-free rose-like copper sulfide (CuS) microflowers were prepared by a simple one-pot solvothermal method in N,N-dimethylformamide (DMF).

In situ sulfuration synthesis of flexible PAN-CuS “flowering branch” heterostructures as recyclable catalysts for dye degradation

“Flowering branch”-like PAN-CuS hierarchical heterostructures were in situ synthesized through a facile hydrothermal sulfuration growth process on PAN-based fibers prepared by electrospinning. The PAN fibers can serve as a stable flexible support, while CuS flowers assembled from nanosheets can act as reactive materials, showing high performance in the degradation of dyes. Moreover, these heterostructures can be recovered easily without a decrease in their photocatalytic activity, thus showing favorable recycling capability.

“Flowering branch”-like PAN-CuS hierarchical heterostructures were in situ synthesized through a facile hydrothermal sulfuration growth process on PAN-based fibers prepared by electrospinning.

Enhanced reactive oxygen species through direct copper sulfide nanoparticle-doxorubicin complexation

CuS-based nanostructures loading the chemotherapeutic agent doxorubicin (DOX) exerted excellent cancer photothermal chemotherapy under multi-external stimuli. The DOX loading was generally designed through electrostatic interaction or chemical linkers. However, the interaction between DOX molecules and CuS nanoparticles has not been investigated. In this work, we use PEGylated hollow copper sulfide nanoparticles (HCuSNPs) to directly load DOX through the DOX/Cu²⁺ chelation process. Distinctively, the synthesized PEG-HCuSNPs-DOX release the DOX/Cu²⁺ complexes into surrounding environment, which generate significant reactive oxygen species (ROS) in a controlled manner by near-infrared laser. The CuS nanoparticle-mediated photothermal ablation facilitates the ROS-induced cancer cell killing effect. Our current work reveals a DOX/Cu²⁺-mediated ROS-enhanced cell-killing effect in addition to conventional photothermal chemotherapy through the direct CuS nanoparticle-DOX complexation.

Diversified copper sulfide (Cu2-xS) micro-/nanostructures: a comprehensive review on synthesis, modifications and applications

As a significant metal chalcogenide, copper sulfide (Cu_2-xS, 0 < x < 1), with a unique semiconducting and nontoxic nature, has received significant attention over the past few decades. Extensive investigations have been employed to the various Cu_2-xS micro-/nanostructures owing to their excellent optoelectronic behavior, potential thermoelectric properties, and promising biomedical applications. As a result, micro-/nanostructured Cu_2-xS with well-controlled morphologies, sizes, crystalline phases, and compositions have been rationally synthesized and applied in the fields of photocatalysis, energy conversion, in vitro biosensing, and in vivo imaging and therapy. However, a comprehensive review on diversified Cu_2-xS micro-/nanostructures is still lacking; therefore, there is an imperative need to thoroughly highlight the new advances made in function-directed Cu_2-xS-based nanocomposites. In this review, we have summarized the important progress made in the diversified Cu_2-xS micro-/nanostructures, including that in the synthetic strategies for the preparation of 0D, 1D, 2D, and 3D micro-/nanostructures (including polyhedral, hierarchical, hollow architectures, and superlattices) and in the development of modified Cu_2-xS-based composites for enhanced performance, as well as their various applications. Furthermore, the present issues and promising research directions are briefly discussed.

Compound Copper Chalcogenide Nanocrystals

This review captures the synthesis, assembly, properties, and applications of copper chalcogenide NCs, which have achieved significant research interest in the last decade due to their compositional and structural versatility. The outstanding functional properties of these materials stems from the relationship between their band structure and defect concentration, including charge carrier concentration and electronic conductivity character, which consequently affects their optoelectronic, optical, and plasmonic properties. This, combined with several metastable crystal phases and stoichiometries and the low energy of formation of defects, makes the reproducible synthesis of these materials, with tunable parameters, remarkable. Further to this, the review captures the progress of the hierarchical assembly of these NCs, which bridges the link between their discrete and collective properties. Their ubiquitous application set has cross-cut energy conversion (photovoltaics, photocatalysis, thermoelectrics), energy storage (lithium-ion batteries, hydrogen generation), emissive materials (plasmonics, LEDs, biolabelling), sensors (electrochemical, biochemical), biomedical devices (magnetic resonance imaging, X-ray computer tomography), and medical therapies (photochemothermal therapies, immunotherapy, radiotherapy, and drug delivery). The confluence of advances in the synthesis, assembly, and application of these NCs in the past decade has the potential to significantly impact society, both economically and environmentally.

Protein-Modified CuS Nanotriangles: A Potential Multimodal Nanoplatform for In Vivo Tumor Photoacoustic/Magnetic Resonance Dual-Modal Imaging

Controllable preparation of water-soluble multifunctional nanoprobes is of great significance for cancer early diagnosis. In this study, protein-modified hydrophilic copper sufide (CuS) nanotriangles with tunable absorption in the second near-infrared region are developed in the presence of halide ions. Further, gadolinium ions chelated diethylenetriaminepentaacetic acid is conjugated on it by using the unique characteristics of the protein-protected nanotriangles. Specifically, the as-obtained nanostructures are investigated as contrast agents for enhanced in vivo photoacoustic/magnetic resonance dual-modal tumor imaging. More importantly, in vitro and in vivo toxicity analysis are also performed, which show that the dual-modal nanoprobes are biocompatible for most of the cases. It is demonstrated that the novel as-prepared protein-modified nanotriangles are able to work as a nanoplatform to construct dual-modal nanoprobes, which paves a new avenue for improving the photoacoustic/magnetic resonance imaging contrast in cancer detection. It should be pointed out that other functional blocks may also be linked on it, which makes it a general method to design multifunctional nanoprobes.

Polypyrrole-modified CuS nanoprisms for efficient near-infrared photothermal therapy

PPy-Modified CuS nanoprisms with intense near-infrared absorption, excellent biocompatibility and photothermal conversion performance, were applied to in vivo photothermal therapy.

Microfluidic Synthesis and Biological Evaluation of Photothermal Biodegradable Copper Sulfide Nanoparticles

The continuous synthesis of biodegradable photothermal copper sulfide nanoparticles has been carried out with the aid of a microfluidic platform. A comparative physicochemical characterization of the resulting products from the microreactor and from a conventional batch reactor has been performed. The microreactor is able to operate in a continuous manner and with a 4-fold reduction in the synthesis times compared to that of the conventional batch reactor producing nanoparticles with the same physicochemical requirements. Biodegradation subproducts obtained under simulated physiological conditions have been identified, and a complete cytotoxicological analysis on different cell lines was performed. The photothermal effect of those nanomaterials has been demonstrated in vitro as well as their ability to generate reactive oxygen species.

Consecutive Reaction to Construct Hierarchical Nanocrystalline CuS "Branch" with Tunable Catalysis Properties

New CuS nanocrystals with a 3D hierarchical branched structure are successfully synthesized through in situ consecutive reaction method with copper foam as template. The formation mechanism of the 3D hierarchical branched structure obtained from the secondary reaction is investigated by adjusting the reaction time. The morphology of CuS nanosheet arrays with the 3D hierarchical branched structure is changed through Cu(2+) exchange. In this method, the copper foam reacted completely, and the as-synthesized CuS@Cu9S5 nanocrystals are firmly grown on the surface of the 3D framework. This tunable morphology significantly influence the physical and chemical properties, particularly catalytic performance, of the materials. The as-obtained material of Cu@CuS-2 with the 3D hierarchical branched structure as catalyst for methylene blue degradation exhibits good catalytic performance than that of the material of Cu@CuS with 2D nanosheets in dark environment. Furthermore, the cation exchange between Cu and Cu(2+) indicates that Cu(2+) in wastewater could be absorbed by Cu@CuS-2 with the 3D hierarchical branched structure. The exchanged resultant of CuS@Cu9S5 retains its capability to degrade organic dyes. This in situ consecutive reaction method may have a significant impact on controlling the crystal growth direction of inorganic material.

Biomineralization-Inspired Synthesis of Copper Sulfide-Ferritin Nanocages as Cancer Theranostics

It is essential to control the size and morphology of nanoparticles strictly in nanomedicine. Protein cages offer significant potential for templated synthesis of inorganic nanoparticles. In this study, we successfully synthesized ultrasmall copper sulfide (CuS) nanoparticles inside the cavity of ferritin (Fn) nanocages by a biomimetic synthesis method. The uniform CuS-Fn nanocages (CuS-Fn NCs) showed strong near-infrared absorbance and high photothermal conversion efficiency. In quantitative ratiometric photoacoustic imaging (PAI), the CuS-Fn NCs exhibited superior photoacoustic tomography improvements for real-time in vivo PAI of entire tumors. With the incorporation of radionuclide (64)Cu, (64)CuS-Fn NCs also served as an excellent PET imaging agent with higher tumor accumulation compared to free copper. Following the guidance of PAI and PET, CuS-Fn NCs were applied in photothermal therapy to achieve superior cancer therapeutic efficiency with good biocompatibility both in vitro and in vivo. The results demonstrate that the bioinspired multifunctional CuS-Fn NCs have potential as clinically translatable cancer theranostics and could provide a noninvasive, highly sensitive, and quantitative in vivo guiding method for cancer photothermal therapies in experimental and clinical settings.

The surfactant-free synthesis of hollow CuS nanospheres via clean Cu2O templates and their catalytic oxidation of dye molecules with H2O2

Hollow CuS nanospheres were synthesized by clean Cu₂O nanoaggregates as template. The hollow CuS nanospheres were highly efficient catalysts for dye degradation with H₂O₂ in the darkness.

Synthetic methods of CuS nanoparticles and their applications for imaging and cancer therapy

A comprehensive survey of basic concepts and up-to-date literature results concerning the potential use of CuS nanoparticles for biomedical applications.

Ultrafast Hole Trapping and Relaxation Dynamics in p-Type CuS Nanodisks

CuS nanocrystals are potential materials for developing low-cost solar energy conversion devices. Understanding the underlying dynamics of photoinduced carriers in CuS nanocrystals is essential to improve their performance in these devices. In this work, we investigated the photoinduced hole dynamics in CuS nanodisks (NDs) using the combination of transient optical (OTA) and X-ray (XTA) absorption spectroscopy. OTA results show that the broad transient absorption in the visible region is attributed to the photoinduced hot and trapped holes. The hole trapping process occurs on a subpicosecond time scale, followed by carrier recombination (~100 ps). The nature of the hole trapping sites, revealed by XTA, is characteristic of S or organic ligands on the surface of CuS NDs. These results not only suggest the possibility to control the hole dynamics by tuning the surface chemistry of CuS but also represent the first time observation of hole dynamics in semiconductor nanocrystals using XTA.

Direct Dry-Grinding Synthesis of Monodisperse Lipophilic CuS Nanoparticles

Copper sulfide nanoparticles, effective absorbers of near-infrared light, are recently attracting broad interest as a photothermal coupling agent for cancer therapy. Lipophilic copper sulfide nanoparticles are preferred for high performance biomedical applications due to high tissue affinity. Synthesis of lipophilic copper sulfide nanoparticles requires complicated multi-step processes under severe conditions. Here, we describe a new synthetic process, developed by direct dry-grinding of copper(II) acetylacetonate with sulfur under ambient environment at low temperature. The formed CuS nanoparticles are of uniform size, ~10 nm in diameter, and are monodispersed in chloroform. Each covellite CuS nanocrystal surface is modified with oleylamine through hydrogen bonding between sulfur atoms and amine groups of oleylamine. The nanoparticles demonstrate near-infrared light absorption for photothermal applications. The synthetic methodology described here is more convenient and less extreme than previous methods, and should thus greatly facilitate the preparation of photothermal lipophilic copper sulfide nanomaterials for cancer therapy.

An electrochemical sensor based on reduced graphene oxide and copper sulfide hollow nanospheres

A nonenzymatic sensor for the detection of hydrogen peroxide (H₂O₂) was fabricated with reduced graphene oxide (RGO) and copper sulfide hollow nanospheres (CuSHNs).

Sub-ppm electrical detection of hydrogen sulfide gas at room temperature based on printed copper acetate–gold nanoparticle composite films

This paper presents the sub-ppm level electrical detection of H₂S gas at room temperature using printed copper acetate–gold nanoparticle composite films either on (A) silver or (B) gold/AuNP electrodes.

Synthesis of a flower-like CuS/ZnS nanocomposite decorated on reduced graphene oxide and its photocatalytic performance

CZS/rGO composites with enhanced photocatalytic activity have been synthesized. The results demonstrate that the CZS/rGO composites have enormous potential for photodegradation of organic pollutants. The enhanced mechanism was also explained.

Porous hollow CuS nanospheres with prominent peroxidase-like activity prepared in large scale by a one-pot controllable hydrothermal step

Porous hollow CuS nanospheres with a variety of sizes were fabricated by an innovative one-pot method based on a facile template-assisted hydrothermal approach at low temperatures. The as-prepared CuS nanospheres exhibited a very prominent intrinsic peroxidase-like activity.

Controllable synthesis of various kinds of copper sulfides (CuS, Cu7S4, Cu9S5) for high-performance supercapacitors

The whole shape evolutionary process of snowflake-like Cu₇S₄ microstructures could be controlled by adjusting the concentration of ethylenediamine.

A controlled solvothermal synthesis of CuS hierarchical structures and their natural-light-induced photocatalytic properties

A solvothermal synthesis of CuS hierarchical structures for the photodegradation of methylene blue (MB).

Preparation of monodispersed CuS nanocrystals in an oleic acid/paraffin system

Well-dispersed CuS nanocrystals were synthesized through a simple hot injection approach using cupric oxide and elemental sulfur as the precursors in an oleic acid/liquid paraffin system.