Copper Selenide Nanoparticles Research Articles

Fluorescence detection of valence speciation of Cr(III) based on the catechol oxidase mimic enzyme activity of CuSeNP nanozymes.

Copper selenide nanoparticles (CuSeNP) weresynthesized using histidine, ethylenediamine, and sodium selenate as precursors by one-step microwave digestion methods. The as-prepared CuSeNPs exhibit excellent catechol oxidase mimic enzyme and catalase (CAT)-like activities. Dopamine (DA) can be oxidized to aminochrome with H2O2 by CuSeNPs, and the intermediate product aminochrome can further react with α-naphthol to yield a highly fluorescent derivative. It was confirmed that Cr(III) could adsorb on the surface of CuSeNPs and inhibit the production of semiquinone radicals in the reaction system, and the catalytic activity of CuSeNPs was inhibited. The detection mechanisms, kinetics, and catalytic properties of CuSeNPs were systematically investigated. As a result, a novel fluorescence method for the assay of Cr(III) was established. The feasibility of CuSeNP nanozyme in detecting speciation Cr(III) in food samples was explored with satisfactory results. It showed the obvious potential for developing effective and dependable fluorescent detection method for protecting food safety.

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.

Synthesis and Superficial Modification "In Situ" of Copper Selenide (Cu2-x Se) Nanoparticles and Their Antibacterial Activity.

Copper selenide nanoparticles (Cu2-x Se NPs) have received a lot of attention in recent decades due to their interesting properties and potential applications in various areas such as electronics, health, solar cells, etc. In this study, details of the synthesis and characterization of copper selenide nanoparticles modified with gum arabic (GA) are reported. Also, through transmission electronic microscopy (TEM) analysis, the transformation of the morphology and particle size of copper selenide nanoparticles in aqueous solution was studied. In addition, we present an antimicrobial study with different microorganisms such as Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albiacans (C. albicans). Copper selenide nanoparticles were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry analysis (DSC) and TEM. XRD confirmed the crystal-line structure of the nanoparticles such as cubic berzelanite with a particle size of 6 nm ± 0.5. FTIR and TGA corroborated the surface modification of copper selenide nanoparticles with gum arabic, and DSC suggested a change in the structural phase from cubic to hexagonal. TEM analysis demonstrated that the surface modification of the Cu2-x Se NPs stabilized the nanostructure of the particles, preventing changes in the morphology and particle size. The antimicrobial susceptibility analysis of copper selenide nanoparticles indicated that they have the ability to inhibit the microbial growth of Staphylococcus aureus, Escherichia coli and Candida albicans.

Decellularized periosteum and sodium alginate-based photoresponsive dressing with copper selenide nanoparticles for infected-wound healing in diabetic mice

Diabetes-related skin ulcers are of significant clinical concern. Although conventional dressings have been developed, their outcomes have not been adequate, indicating the need to investigate functional dressings for the treatment of diabetic ulcers. Copper selenide nanoparticles (Cu2Se NPs) demonstrate outstanding photoresponsiveness, which is critical to the healing process. However, their limited solubility in water restricts their application. To synthesize the ODT-PMMA@Cu2Se NP-doped decellularized periosteum‑sodium alginate functional dressing-ODT-PMMA@Cu2Se/ECM-S (OP@Cu2Se/ECM-S), Cu2Se NPs were modified by n-octadecanethiol (ODT) end-functionalized poly (methacrylic acid) (PMAA) ligands homogeneously dispersed in a decellularized periosteum/sodium alginate matrix. This process improved the water solubility and stability. Moreover, under near-infrared irradiation (NIR), ODT-PMMA@Cu2Se demonstrated robust photo-responsiveness along with photothermal and photodynamic effects, leading to rapid heating and stimulation of reactive oxygen species (ROS) generation. These two processes work in concert to exhibit excellent antibacterial ability; at 20 μg/mL concentration of Cu2Se NPs, the bacterial activities of S. aureus and E. coli were 5.40 % and 0.96 %, respectively. Without the NIR laser irradiation, OP@Cu2Se/ECM-S rapidly increased the vascular endothelial growth factor (VEGF) expression, triggered the phosphatidylinositide 3-kinases (PI3K) and protein kinase B (AKT) signaling pathway, affected the expression of bFGF and CD31, and promoted neovascularization, proliferation, and cell migration. In a diabetic mouse wound model, OP@Cu2Se/ECM-S exhibited good biocompatibility and promoted epidermal regeneration, collagen deposition, and neovascularization. In a mouse model of subcutaneous abscesses, OP@Cu2Se/ECM-S also showed excellent antibacterial activity, in vivo experiments confirmed a decrease in bacterial activity to 1.97 %. Thus, OP@Cu2Se/ECM-S is a potentially useful approach for healing diabetic wounds.

A tissue-adhesive F127 hydrogel delivers antioxidative copper-selenide nanoparticles for the treatment of dry eye disease

Dry eye disease (DED) is currently the most prevalent condition seen in ophthalmology outpatient clinics, representing a significant public health issue. The onset and progression of DED are closely associated with oxidative stress-induced inflammation and damage. To address this, an aldehyde-functionalized F127 (AF127) hydrogel eye drop delivering multifunctional antioxidant Cu2−xSe nanoparticles (Cu2−xSe NPs) was designed. The research findings revealed that the Cu2−xSe nanoparticles exhibit unexpected capabilities in acting as superoxide dismutase and glutathione peroxidase. Additionally, Cu2−xSe NPs possess remarkable efficacy in scavenging reactive oxygen species (ROS) and mitigating oxidative damage. Cu2−xSe NPs displayed promising therapeutic effects in a mouse model of dry eye. Detailed investigation revealed that the nanoparticles exert antioxidant, anti-apoptotic, and inflammation-mitigating effects by modulating the NRF2 and p38 MAPK signalling pathways. The AF127 hydrogel eye drops exhibit good adherence to the ocular surface through the formation of Schiff-base bonds. These findings suggest that incorporating antioxidant Cu2−xSe nanoparticles into a tissue-adhesive hydrogel could present a highly effective therapeutic strategy for treating dry eye disease and other disorders associated with reactive oxygen species. Statement of significanceA new formulation for therapeutic eye drops to be used in the treatment of dry eye disease (DED) was developed. The formulation combines copper-selenium nanoparticles (Cu2-xSe NPs) with aldehyde-functionalized Pluronic F127 (AF127). This is the first study to directly examine the effects of Cu2-xSe NPs in ophthalmology. The NPs exhibited antioxidant capabilities and enzyme-like properties. They effectively eliminated reactive oxygen species (ROS) and inhibited apoptosis through the NRF2 and p38 MAPK signalling pathways. Additionally, the AF127 hydrogel enhanced tissue adhesion by forming Schiff-base links. In mouse model of DED, the Cu2-xSe NPs@AF127 eye drops demonstrated remarkable efficacy in alleviating symptoms of DED. These findings indicate the potential of Cu2-xSe NPs as a readily available and user-friendly medication for the management of DED.

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.

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.

Photocatalytic Degradation of Methylene Blue Dye Using Copper Selenide Nanoparticles Prepared by Co- Precipitation Method

Photocatalytic Degradation of Methylene Blue Dye Using Copper Selenide Nanoparticles Prepared by Co- Precipitation Method

Biogenic Copper Selenide Nanoparticles for Near-Infrared Photothermal Therapy Application.

Near-infrared (NIR) photothermal therapy (PTT) is attractive for cancer treatment but is currently restricted by limited availability and insufficient NIR-II photoactivity of photothermal agents, for which artificial nanomaterials are usually used. Here, we report the first use of biogenic nanomaterials for PTT application. A fine-controlled extracellular biosynthesis of copper selenide nanoparticles (bio-Cu2-xSe) by Shewanella oneidensis MR-1 was realized. The resulting bio-Cu2-xSe, with fine sizes (∼35.5 nm) and high product purity, exhibited 76.9% photothermal conversion efficiency under 1064 nm laser irradiation, outperforming almost all the existing counterparts. The protein capping also imparted good biocompatibility to bio-Cu2-xSe to favor a safe PTT application. The in vivo PTT with injected bio-Cu2-xSe in mice (without extraction nor further modification) showed 87% tumor ablation without impairing the normal organisms. Our work not only opens a green route to synthesize the NIR-II photothermal nanomaterial but may also lay a basis for the development of bacteria-nanomaterial hybrid therapy technologies.

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.

Two birds with one stone: A multifunctional nanoplatform for photothermal sensitive detection and real-time inactivation of Staphylococcus aureus with NIR responsive Cu2−XSe@Van NPs

Susceptibility point-of-care testing (POCT) and bacterial inactivation are crucial for food safety and clinical diagnosis since bacteria pose a severe hazard to public health and healthcare. To enable photothermal determination and hyperthermal inactivation of bacteria, vancomycin-modified near-infrared (NIR)-responsive copper selenide nanoparticles (Cu2−XSe@Van NPs) with excellent photothermal conversion are synthesized here. Cu2−XSe@Van NPs can be trapped on the surface of Gram-positive bacteria such as Staphylococcus aureus (S. aureus), forming a Cu2−XSe@Van NPs/S. aureus complex. Suspension (Cu2−XSe@Van NPs) and sediment (Cu2−XSe@Van NPs/S. aureus) can convert the NIR laser energy into a thermal signal that can be detected by the thermal camera at concentrations as low as 6.0 CUF mL−1. Meanwhile, S. aureus can be effectively inactivated by localized temperature rises during temperature-based signal detection. The antibacterial efficiency can reach as high as 99.53%. The proposed strategy not only provides a sensitive POCT strategy for bacterial determination but also implements efficient inactivation of bacteria simultaneously.

X-ray diffraction (XRD) profile analysis and optical properties of Klockmannite copper selenide nanoparticles synthesized via microwave assisted technique

In this study, copper selenide (CuSe) nanoparticles (NPs) were prepared using the microwave irradiation technique. The effect of the irradiation time on the structural properties of CuSe NPs was investigated. The XRD results confirms the formation of the hexagonal (Klockmannite) structure of CuSe NPs. Different X-ray diffraction profile analysis techniques comprising strain-size plot (SSP), Scherer’s method (S-M), Monshi-Scherer’s method (MSM), Halder-Wagner (H–W) technique, and Williamson-Hall technique (WHM) were employed to examine the effect of irradiation time on the particle size as well as intrinsic strain of CuSe NPs using XRD peak broadening analysis. Uniform deformation model, uniform stress deformation model, as well as uniform energy density deformation model of Williamson-Hall technique were used to calculate the average crystallites size of CuSe NPs. Essential physical variables involving stress and energy density were also computed. Also, field emission scanning electron microscope (FESEM) in addition to atomic force microscopy (AFM) were further used to determine the mean particle size of CuSe NPs depending on varying irradiation time. The obtained results were found to be in agreement and comparable with the results of XRD profile analysis methods. Raman spectroscopy revealed three vibrational bands which are ascribed to the CuSe vibrational modes. Furthermore, the optical characteristics of the synthesized CuSe NPs were also investigated. The result obtained revealed a decrease in the optical bandgap from 2.43 to 2.71 eV with increase in irradiation time. Photoluminescence study revealed two peaks at 530, and 610 nm respectively. Therefore, it can de deduced that inclusion of intrinsic strain play an important role on the estimation of CuSe NPs size and microstrain of CuSe NPs synthezed vi microwave assisted synthesis technique.

A new cadmium oxide (CdO) and copper selenide (CuSe) nanocomposite: An energy-efficient electrode for wide-voltage hybrid supercapacitors

In this paper, cadmium oxide (CdO) was effectively developed on copper selenide (CuSe) nanoparticles via the wet-chemical method for the first time to explore their electrochemical properties for hybrid supercapacitors (HSC). The XRD Raman analysis proves the successful formation of the CdO, CuSe, and CdO-CuSe nanocomposite. The morphological results exposed that CdO and CuSe are composed of irregular particles-like morphology. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) analysis demonstrated the battery-type behavior of the electrode materials, with prominent redox peaks and voltage plateau in the GCD profile with good reversibility. Interestingly, it was observed that the freshly prepared CdO-CuSe electrode displays a relatively higher capacity (386 C/g) compared to CdO and CuSe electrodes (175 and 216 C/g). Furthermore, we built a CdO-CuSe//AC HSC, which expanded the voltage limit to 1.8 V. It delivered a high energy and power densities of 51 Wh kg−1 and retained 16 Wh kg−1 when power density reached its maximum value of 6488 W kg−1. More importantly, a stable cycling performance (94.8%) was attained after 9000 cycles at the highest current rate of 15 A g−1, which can be attributed to the high conductivity, which offers more active sites for electrolyte ions on the electrode surface.

AQDS Activates Extracellular Synergistic Biodetoxification of Copper and Selenite via Altering the Coordination Environment of Outer-Membrane Proteins.

The biotransformation of heavy metals in the environment is usually affected by co-existing pollutants like selenium (Se), which may lower the ecotoxicity of heavy metals, but the underlying mechanisms remain unclear. Here, we shed light on the pathways of copper (Cu2+) and selenite (SeO32-) synergistic biodetoxification by Shewanella oneidensis MR-1 and illustrate how such processes are affected by anthraquinone-2,6-disulfonate (AQDS), an analogue of humic substances. We observed the formation of copper selenide nanoparticles (Cu2-xSe) from synergistic detoxification of Cu2+ and SeO32- in the periplasm. Interestingly, adding AQDS triggered a fundamental transition from periplasmic to extracellular reaction, enabling 14.7-fold faster Cu2+ biodetoxification (via mediated electron transfer) and 11.4-fold faster SeO32- detoxification (via direct electron transfer). This is mainly attributed to the slightly raised redox potential of the heme center of AQDS-coordinated outer-membrane proteins that accelerates electron efflux from the cells. Our work offers a fundamental understanding of the synergistic detoxification of heavy metals and Se in a complicated environmental matrix and unveils an unexpected role of AQDS beyond electron mediation, which may guide the development of more efficient environmental remediation and resource recovery biotechnologies.

Phase Engineering of Defective Copper Selenide toward Robust Lithium-Sulfur Batteries.

The shuttling of soluble lithium polysulfides (LiPS) and the sluggish Li-S conversion kinetics are two main barriers toward the practical application of lithium-sulfur batteries (LSBs). Herein, we propose the addition of copper selenide nanoparticles at the cathode to trap LiPS and accelerate the Li-S reaction kinetics. Using both computational and experimental results, we demonstrate the crystal phase and concentration of copper vacancies to control the electronic structure of the copper selenide, its affinity toward LiPS chemisorption, and its electrical conductivity. The adjustment of the defect density also allows for tuning the electrochemically active sites for the catalytic conversion of polysulfide. The optimized S/Cu1.8Se cathode efficiently promotes and stabilizes the sulfur electrochemistry, thus improving significantly the LSB performance, including an outstanding cyclability over 1000 cycles at 3 C with a capacity fading rate of just 0.029% per cycle, a superb rate capability up to 5 C, and a high areal capacity of 6.07 mAh cm-2 under high sulfur loading. Overall, the present work proposes a crystal phase and defect engineering strategy toward fast and durable sulfur electrochemistry, demonstrating great potential in developing practical LSBs.

Solvothermal synthesis and characterization studies of selenium decorated reduced graphene oxide supported CuSe2 nanoparticles as efficient electrochemical catalyst for oxygen reduction reaction

In the energy conversion system, oxygen reduction reaction (ORR) is one of the most significant reactions. Pt-based catalysts are commonly used in fuel cells; the replacement with low-cost materials like transition metal oxides is much needed for the wide application of fuel cells. In this paper, the effective synthesis of copper selenide nanoparticles with selenium-reduced graphene oxide has been described. To establish the existence of selenium, graphene, and copper in manufactured samples, X-Ray diffraction analysis (XRD) has been used. Additionally, fourier transform infrared analysis (FTIR) has been used to examine the functional groups. The structure and morphology have been studied under the scanning electron microscope. UV has been used to assess the synthetic nanoparticles' optical performance. The Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods have been used to analyze their specific surface area and pore size. Cyclic voltammetry has been used to evaluate the produced nanoparticles' electrochemical performance (CV, LSV).

Controllable synthesis of surfactants (PEG and SDS) assisted Copper Selenide Nanoparticles by hydrothermal method for photocatalytic activity

Semiconductor metal chalcogenide nanomaterials are excellent materials which possess interesting properties like existing in different structures under different conditions of synthesis, layered growth nature, low tunable bandgap and can be grown in ambient environmental conditions, etc. Copper Selenide (Cu2Se) is an important p-type semiconducting material, with band gaps 1.2–2.3 eV. Copper Selenide has a wide range of applications in various areas of research such as optical filters, super ionic conductors, window materials, thermal electric conductors and photo electric devices. The experimental synthesis of copper selenide was carried out by the hydrothermal route. The size of nanomaterials can be controlled when it is capped with different types of surfactants (cationic, anionic, nonionic or Zwitter ionic). Two types of surfactants, say sodium dodecyl sulphate (SDS), an anionic surfactant and polyethylene glycol (PEG), a non-ionic surfactant were chosen to study their influence on the particle size. The various characterization techniques namely XRD, UV, SEM, TEM, Dielectric studies and photocatalytic activity were adopted to analysis the samples.

Tailored Chiral Copper Selenide Nanochannels for Ultrasensitive Enantioselective Recognition and Detection.

We constructed a tailorable membrane channel system consisting of penicillamine molecules intercalated in copper selenide nanoparticles (Cu2-x Se NPs), which exhibited circular dichroism (CD) bands in the near infrared region (CD, 800-1600 nm) with a maximum intensity of 164.5 mdeg at 1440 nm. The chiral ligand hybridized to the surface of achiral Cu2-x Se NPs by breaking the intrinsic symmetry of Cu2-x Se NPs and further large-scale assembly induced strong optical activity. The fabricated multilayer chiral membrane achieved an increased rectification ratio (RR) up to 114. The integration of penicillamine allowed for high enantioselective recognition against naproxen,which displayed high sensitivity with a limit of detection (LOD) as low as 0.027 nM.

Tailored Chiral Copper Selenide Nanochannels for Ultrasensitive Enantioselective Recognition and Detection

AbstractWe constructed a tailorable membrane channel system consisting of penicillamine molecules intercalated in copper selenide nanoparticles (Cu2−xSe NPs), which exhibited circular dichroism (CD) bands in the near infrared region (CD, 800–1600 nm) with a maximum intensity of 164.5 mdeg at 1440 nm. The chiral ligand hybridized to the surface of achiral Cu2−xSe NPs by breaking the intrinsic symmetry of Cu2−xSe NPs and further large‐scale assembly induced strong optical activity. The fabricated multilayer chiral membrane achieved an increased rectification ratio (RR) up to 114. The integration of penicillamine allowed for high enantioselective recognition against naproxen,which displayed high sensitivity with a limit of detection (LOD) as low as 0.027 nM.

Fluorinated Chitosan Mediated Synthesis of Copper Selenide Nanoparticles with Enhanced Penetration for Second Near‐Infrared Photothermal Therapy of Bladder Cancer

AbstractThe emergence of near‐infrared‐II (NIR‐II) light activated photomedicines has extended the penetration depth for noninvasive theranostics, especially for photothermal nanomedicines. Intravesical instillation therapy of bladder cancer (BCa) is restricted greatly due to the short residence time and the low penetration ability of therapeutic agents in clinic. Therefore, improving the mucoadhesiveness and penetration of therapeutic agents are crucial factors in treatment of BCa. The development of NIR‐II light triggered photothermal transduction agents for enhanced penetration and photothermal ablation of BCa post‐intravesical instillation has not yet been investigated. Herein, Cu2‐xSe biocompatible particles are prepared through a fluorinated chitosan (FCS)‐mediated one‐pot aqueous approach, which possesses enhanced penetrating ability and high photothermal conversion capability for effective NIR‐II photothermal therapy (PTT). Owing to the outstanding transmucosal ability of FCS, FCS capped Cu2‐xSe nanoparticles exhibit much better transmucosal and penetration performance than their non‐fluorinated counterparts to significantly improve the therapeutic efficacy of NIR‐II PTT to ablate orthotopic bladder tumors. This study presents a promising phototherapy agent based on Cu2‐xSe modified with FCS for efficient NIR‐II PTT for BCa treatment post‐intravesical instillation.