Search Results (139)

Organic phase-change materials (PCMs) offer great promise in addressing challenges in thermal energy storage and heat management, but their applications are greatly limited by low energy density and a rigid phase transition temperature. Herein, by introducing carbon dots (CDs) with abundant oxygen-related groups, we develop a novel kind of erythritol (ET)-based composite PCMs (CD-ETs) featuring an enhanced latent heat storage capacity and a reduced degree of supercooling compared to pure ETs. The optimally formulated CD-ETs increase the latent heat storage capacity from 377.3 to 410.2 J·g⁻¹ and the heat release capacity from 209.0 to 240.2 J·g⁻¹ compared to the pristine ETs. Moreover, the subcooled degree of CD-ETs is more than 30 °C lower than that of pristine ETs. By successively encapsulating CD-ETs and CD-containing polyethylene glycol (PEG) with a low melting point in a reduced graphene oxide-modified melamine sponge, the resultant shape-stabilized system not only prevents leakage of molten PCMs but also allows for a wide response temperature window and promotes the heat transfer ability of melted PEG in close contact with solid CD-ETs. Stepped melting and crystallization guarantee phase changes in high-melting-point ETs via solar heating, Joule heating or a combination thereof. Specifically, the melting enthalpy of this system is as high as 306.5 J·g⁻¹, and its cold crystallization enthalpy reaches 196.5 J·g⁻¹, surpassing numerous organic PCMs. This work provides a facile and efficient strategy for the design of ideal thermal energy storage materials to meet the needs of application scenarios in a cost-effective manner. Full article

Colorectal cancer poses a significant threat to human health due to its high aggressiveness and poor prognosis. Key factors impacting patient outcomes include post-surgical recurrence, chemotherapeutic drug resistance, and insensitivity to immunotherapy. Consequently, early diagnosis and the development of effective targeted therapies are essential for improving prevention and treatment strategies. Inorganic nanomaterials have gained prominence in the diagnosis and treatment of colorectal cancer owing to their unique size, advantageous properties, and high modifiability. Various types of inorganic nanomaterials—such as metal-based, metal oxide, quantum dots, magnetic nanoparticles, carbon-based, and rare-earth nanomaterials—have demonstrated significant potential in enhancing multimodal imaging, drug delivery, and synergistic therapies. These advancements underscore their critical role in improving therapeutic outcomes. This review highlights the properties and development of inorganic nanomaterials, summarizes their recent applications and progress in colorectal cancer diagnosis and treatment, and discusses the challenges in translating these materials into clinical use. It aims to provide valuable insights for future research and the clinical application of inorganic nanomaterials in colorectal cancer management. Full article

In this work, a novel molecularly imprinted electrochemical sensor was proposed based on molecular imprinting technology for the detection of sulfamethazine. A glassy carbon electrode was modified with a composite material of carbon nanotubes and graphene quantum dots to effectively improve sensitivity. The molecularly imprinted electrochemical sensor was then prepared by electropolymerization using sulfamethazine as the template and o-phenylenediamine as the functional monomer on the modified electrode. Under optimal measurement conditions, electrochemical tests of different sulfamethazine concentrations (0.5 μM–200 μM) showed excellent linearity and a detection limit of 0.068 μM. In addition, the sensor demonstrated satisfactory selectivity, stability, and reusability. Furthermore, the sensor was applied to the spiked analysis of sulfamethazine in grouper aquaculture water, achieving recovery rates between 95.4% and 104.8%, with a relative standard deviation (RSD) of less than 4.14%. These results indicated that the developed method was effective for the analysis of sulfamethazine in aquaculture seawater, providing a new approach for the detection of antibiotic residues in seawater samples. Full article

Nowadays, carbon dots (CDs) with a variety of structures and compositions are widely applied in the petroleum industry, including tracers, modification of interfacial properties and regulation of rheological properties due to their excellent modifiability, environmental compatibility, straightforward synthesis, and outstanding photoluminescent properties. In this review, we summarize the applications of CDs in the petroleum industry and elucidate the effects of CDs based on the classification of application scenarios. In addition, we briefly analyze the relationship between the structure of CDs and their performance, identify the challenges we are currently facing, and discuss the structural characteristics of high-performance CDs along with their potential future applications. The discussion presented in this article is based on research on CDs and the petroleum industry. By combining these two areas, this review is expected to provide guidance to researchers working in related areas. Meanwhile, we also hope this review can offer innovative ideas for further applications of CDs in the petroleum industry. Full article

Hydrogen production from water electrolysis offers a highly promising and sustainable route to solve the energy crisis. However, it is severely limited by the sluggish kinetics of the oxygen evolution reaction (OER) occurring on the anode. Herein, employing carbon dots functionalized with benzene sulfonate groups (BS-CDs) as a distinctive inductor, a Co(OH)₂ catalyst featuring abundant defects was synthesized for an enhanced OER. The highly hydrophilic nature of BS-CDs exerts a significant interfacial induction effect on the growth dynamics of Co(OH)₂, fostering the formation of elevated crystal defects and a substantial quantity of oxygen vacancies. The resulting BS-CDs/Co(OH)₂ catalyst requires an overpotential of only 340 mV to achieve a current density of 10 mA cm⁻² in alkaline media, demonstrating markedly improved OER activity compared to pristine Co(OH)₂ and N-CDs/Co(OH)₂ induced by amine-modified CDs. Furthermore, the structural integrity of the catalyst is maintained, with a current retention rate of 92% observed following a 20 h stability assessment. This work provides a novel approach for developing cost-effective transition metal catalysts that exhibit exceptional catalytic efficiency and excellent stability for the OER. Full article

Carbon dots (CDs) are efficient fluorescent probes for metal ion detection due to their high sensitivity, nontoxicity and stability, but their rich functional groups lead to simultaneous responses to multiple ions. So, how to realize highly selective detection for specific ions is still a challenging task. In this work, “bare CDs” were synthesized using the electrochemical stripping method, followed by grafting with hydroxyl and carboxyl groups following the hydrothermal method with boric acid. Transmission electron microscopy, an X-ray diffractometer, Fourier transform infrared spectroscopy, UV–visible spectrophotometers and a fluorescence spectrometer were used to characterize their morphology, surface functional groups and optical properties, respectively. The modified CDs exhibit a high sensitivity of 65% and selectivity towards Cu²⁺. Meanwhile, they also exhibited a short response time of less than 1 min and a good stability in terms of pH and ionic strength. Full article

This study aims to optimize the demulsification performance of a carbon quantum dot (CQD)-enhanced chemical demulsifier in industrial emulsions under thermal, mechanical, and thermomechanical effects. Experiments were conducted to assess treatments like organic treatment (OT), zeta potential modifier aqueous solution (ZPMAS), and acid treatment (9.25 wt.% HCl) at varying dosages, along with CQD–chemical mixtures optimized through a simplex-centroid mixture design (SCMD) to minimize basic sediment and water (BSW). Under the thermomechanical scenario, a system with 500 mg∙L⁻¹ CQDs and OT achieves 0.5% BSW and a droplet size of 63 nm, while an SCMD-optimized system (500 mg∙L⁻¹ CQDs + 380 mg∙L⁻¹ OT + 120 mg∙L⁻¹ ZPMAS) achieves 0% BSW and larger droplets (>70 nm). CQDs enhance demulsifiers by destabilizing water-in-oil (W/O) Pickering emulsions, leveraging their nanometric size, high surface area, thermal conductivity, and amphiphilicity, thanks to their hydrophobic core and surface hydrophilic groups (-OH, NH₂, -COOH). This research enhances the understanding of demulsification by employing green demulsifiers based on CQDs and provides a promising cost-efficient solution for breaking stable emulsions in the petroleum industry. It minimizes the use of complex and expensive active ingredients, achieving BSW values below 0.5%, the standard required for crude oil transport and sale, while also reducing separation equipment operation times, and improving overall process efficiency. Full article

Ethylene glycol (EG) is a colorless and odorless organic compound, which is an important industrial raw material but harmful to the environment and human health. Thus, it is necessary to develop high-performance sensing materials to monitor EG gas. Herein, sea urchin-shaped ZnO was successfully synthesized by a hydrothermal method. Subsequently, a series of carbon dot (CD)-modified ZnO nanocomposites were successfully prepared using a simple mechanical grinding method. The prepared CDs@ZnO-1 sensor exhibits an excellent response to EG gas, with a response value of 1356.89 to 100 ppm EG at the optimal operating temperature (220 °C). After five cycles of detection, the sensor can still maintain a stable response. The enhanced sensing performance of EG can be attributed to rich oxygen vacancies that are generated on the surface of CDs@ZnO, and the heterojunction formed between p-type CDs and n-type ZnO. This study provides inspiration for the development of high-response semiconductor metal oxide sensors. Full article

Carbon dots (CDs), as a revolutionary nanomaterial, exhibit unique advantages in terms of wastewater treatment, offering new opportunities for the development of water treatment technologies due to their simple synthesis methods, excellent biocompatibility, tunable optical properties, and favorable environmental performance. This review systematically discusses the synthesis methods, structural characteristics, and application progress of carbon dots in wastewater treatment, highlighting several key findings. (1) Excellent adsorption performance: CDs can effectively remove heavy metal ions, dyes, and organic pollutants from water. (2) Outstanding photocatalytic performance: Some carbon-dot-enhanced photocatalytic systems can efficiently remove pollutants under visible light. (3) Exceptional selective detection ability: CDs are capable of highly sensitive detection of heavy metals and organic pollutants in water, with the detection limits reaching the nanomolar level. (4) Enhanced membrane separation performance: The high water flux and excellent selectivity of carbon-dot-modified membranes make them suitable for efficient water treatment and water quality separation. (5) Enhancement of biological treatment: In biological treatment systems, CDs can significantly improve the microbial activity and electron transfer efficiency to enhance the efficiency of biological degradation processes. (6) Sustainable utilization of waste as a raw material and regeneration of CDs are conducive to reducing the cost of preparation of CDs. These findings indicate that CDs have broad application potential in wastewater treatment. Furthermore, this review looks ahead to the future development directions of CDs in wastewater treatment, proposing potential innovations in catalytic performance enhancement, cost control, and practical applications, aiming to provide important references and guidance for future research and industrial application of CDs in wastewater treatment. Full article

A novel electrochemical detection method utilizing a cost-effective hybrid-modified electrode has been established. A glassy carbon (GC) modified electrode was tested for its ability to measure electrochemical tTG antibody levels, which are essential for diagnosing and monitoring Celiac disease (CD). Tissue transglutaminase protein biomolecules are immobilized on a quantum dots-polypyrrole nanocomposite in the improved electrode. Initial, quantum dots (QDs) were obtained from Bombyx mori silk fibroin and embedded in polypyrrole film. Using carbodiimide coupling, a polyamidoamine (PAMAM) dendrimer was linked with GQDs-polypyrrole film to improve sensor sensitivity. The tissue transglutaminase (tTG) antigen was cross-linked onto PAMAM using N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC)-N-hydroxy succinimide (NHS) chemistry to develop a nanoprobe that can detect human serum anti-tTG antibodies. The physicochemical characteristics of the synthesized nanocomposite were examined by FTIR, UV-visible, FE-SEM, EDX, and electrochemical studies. The novel electrode measures anti-tissue antibody levels in real time using human blood serum samples. The modified electrode has great repeatability and an 8.7 U/mL detection limit. Serum samples from healthy people and CD patients were compared to standard ELISA kit assays. SPSS and Excel were used for statistical analysis. The improved electrode and detection system can identify anti-tissue antibodies up to 80 U/mL. Full article

In this work, the influence of surface functionalization due to synthesis conditions of graphene oxide quantum dots GOQDs was evaluated for dopamine (DA) detection. GOQDs were synthesized using HNO₃ (6 M or 8 M) through a liquid-phase oxidation method. The characterization (HRTEM, FTIR, Raman, and XRD) and evaluation by amperometry (AMP) and differential pulse voltammetry (DPV) showed that GOQDs-8 synthesized with higher oxygen content were more sensitive and selective in DA detection than GOQDs-6. The synergistic effects of electrostatic attraction from glassy carbon electrode negatively charged surface, functionalization for inner-sphere mechanism, and edge effect from lower particle size resulted in amplified electrochemical signal achieving detection at nanomolar level using AMP and DPV. When evaluated using AMP, GCE/GOQDs-8 showed a sensitivity of 0.0422 μA μM^–1, a limit of detection (LOD) of 17.6 nM, a linear range from 0.1 to 100 μM, and minimal interference for uric acid, levodopa, and acetaminophen. In contrast, using DPV, the GCE/GOQDs-8 exhibited a sensitivity of 0.0616 μA μM^–1, a LOD of 506 nM, and a linear range from 0.1–30 μM with remarkable selectivity from all interferent species. The assay of GOQDs-8/GCE sensor in normal human serum proved to be feasible for the practical determination of DA. The recovery obtained was in the range of 94.1 to 112.8% with a relative standard deviation (RSD), n = 3 of less than 3.62%. The oxygen-rich material showed a promising performance that can be further improved with additional nanocarbon or conducting polymers supports. Full article

Oseltamivir is a drug that has been widely used to prevent and treat influenza A and B. In this work, an ultrasensitive, simple, and novel electrochemiluminescence (ECL) sensor combined with molecularly imprinted polymers (MIP-ECL) based on a graphene-like two-dimensional material, Mxene quantum dots (MQDs) was constructed to selectively detect oseltamivir. A molecularly imprinted polymer membrane containing an oseltamivir template was constructed by electropolymerization and elution of modified MQDs on a glassy carbon electrode. Under optimized experimental conditions, the MIP-ECL sensor could detect oseltamivir in the range of 10⁻¹⁰ to 10⁻⁶ M (R² = 0.9816), with a low limit of detection of 6.5 × 10⁻¹¹ M (S/N = 3), and the recovery rates of oseltamivir in biological samples were 92.21–104.2%, with relative standard deviations of 3.70%~5.70%. The developed MIP-ECL sensor provides a new idea for detecting oseltamivir, which was successfully applied to the determination of oseltamivir in serum samples, indicating great potential for application in clinical diagnostics. Full article

Background: Pathogen bacteria appear and survive on various surfaces made of steel or glass. The existence of these bacteria in different forms causes significant problems in healthcare facilities and society. Therefore, the surface engineering of highly potent antimicrobial coatings is highly important in the 21st century, a period that began with a series of epidemics. Methods: In this study, we prepared two types of photodynamic polyurethane-based composite films encapsulated by N-doped carbon quantum dots and graphene quantum dots irradiated by gamma rays at a dose of 50 kGy, respectively. Further, we investigated their structural, optical, antibacterial, antibiofouling and biocompatibility properties. Results: Nanoelectrical and nanomechanical microscopy measurements revealed deviations in the structure of these quantum dots and polyurethane films. The Young’s modulus of elasticity of the carbon and graphene quantum dots was several times lower than that for single-walled carbon nanotubes (SWCNTs) with chirality (6,5). The electrical properties of the carbon and graphene quantum dots were quite similar to those of the SWCNTs (6,5). The polyurethane films with carbon quantum dots were much more elastic and smoother than the films with graphene quantum dots. Antibacterial tests indicated excellent antibacterial activities of these films against a wide range of tested bacteria, whereas the antibiofouling activities of both composite films showed the best results against the Staphylococcus aureus and Escherichia coli biofilms. Biocompatibility studies showed that neither composite film exhibited any cytotoxicity or hemolysis. Conclusions: Obtained results indicate that these composite films could be used as antibacterial surfaces in the healthcare facilities. Full article

The activated carbon from marigold flowers (MG) was used to make an unlabeled electrochemical immunosensor to determine prostate cancer. MG was synthesized by hydrothermal carbonization and pyrolysis. MG had a large surface area, was highly conductive, and biocompatible. MG modified with graphene quantum dots produced excellent electron transfer for grafting poly(thionine) (PTH). The amine group of PTH bonded with anti-prostate-specific antigen (Anti-PSA) via glutaraldehyde, forming a layer that improved electron transfer. The binding affinity of the immunosensor, presented as the dissociation constant (Kd), was calculated using the Langmuir isotherm model. The results showed that a lower Kd value indicated greater antibody affinity. The immunosensor exhibited two different linear ranges under optimized conditions: 0.0125 to 1.0 ng mL⁻¹ and 1.0 to 80.0 ng mL⁻¹. The sensor could detect concentrations as low as 0.005 ng mL⁻¹, and had a quantification limit of 0.017 ng mL⁻¹. This immunosensor accurately quantified PSA levels of human serum, and the results were validated using enzyme-linked fluorescence assay (ELFA). Full article

China is a significant global producer and consumer of pesticides and antibiotics, with their excessive use leading to substantial water pollution that poses challenges for subsequent treatment. Photocatalytic degradation, leveraging renewable solar energy, presents an effective approach for decomposing organic pollutants and reducing residual contaminant levels in water bodies. This approach represents one effective way for addressing environmental challenges. This paper classifies representative photocatalytic materials by structural design and degradation principles including MOFs (Metal–Organic Frameworks), metal- and nonmetal-doped, mesoporous material-loaded, carbon quantum dot-modified, floatation-based, and heterojunction photocatalysts. We also discuss research on degradation pathways and reaction mechanisms for antibiotics. Of particular importance are several key factors influencing degradation efficiency, which are summarized within this work. These include the separation and charge transfer rate of catalyst surface carriers, and the wide-spectrum response capabilities of photocatalysts, as well as persulfate activation efficiency. Furthermore, emphasis is placed on the significant role played by intrinsic driving forces such as built-in electric fields within catalytic systems. Moreover, this paper introduces several promising composite-structure photocatalytic technologies from both composite-structure perspectives (e.g., Aerogel-based composites) and composite-method perspectives (e.g., the molecularly imprinted synthesis method). We also discuss their latest development status, along with future prospects, presenting valuable insights for pollutant degradation targets. This work aims to facilitate the design of efficient photocatalytic materials, while providing valuable theoretical references for environmental governance technologies. Full article