Application Of Carbon Quantum Dots Research Articles

Recent Biomedical Applications of Carbon Quantum Dots in Cancer Treatment

Recent Biomedical Applications of Carbon Quantum Dots in Cancer Treatment

Response of Soybean Plants to the Foliar Application of Carbon Quantum Dots Under Drought Stress: A Field Study

Response of Soybean Plants to the Foliar Application of Carbon Quantum Dots Under Drought Stress: A Field Study

Visible-Light-Induced Silk Fibroin Hydrogels with Carbon Quantum Dots as Initiators for 3D Bioprinting Applications.

Digital light processing (DLP) 3D bioprinting technology has attracted increasing attention in tissue engineering in recent years. However, it still faces significant technical and operational challenges such as cell carcinogenesis caused by prolonged exposure to ultraviolet light and the presence of heavy metal ions in complex photoinitiator systems. In this study, a novel strategy is designed to introduce carbon quantum dots into visible-light-induced silk fibroin bioink as initiators (CDs/SilMA) applied for DLP 3D bioprinting technology. The incorporation of carbon quantum dots facilitates the formation of precise hydrogel structures at 415 nm visible wavelength, enabling the creation of brain, bronchus, spine, and ear models. Replacing heavy metal photoinitiators with carbon quantum dots imparts fluorescence properties to the bioink and enhances its mechanical properties. Meanwhile, the fibroin protein-based hydrogel exhibits favorable properties, such as drug loading, slow release, degradability, and biocompatibility. This is the first study to propose the application of carbon quantum dots in silk fibroin-based bioink. Moreover, the resulting product demonstrates excellent compatibility with the DLP printing process, making it promising for practical applications in various tissue engineering scenarios with specific requirements.

Lateral flow assemblies and allied application of carbon quantum dots derived from cigarette tobacco in biosensing, anticounterfeiting and fluorescent films: Theoretical and experimental overview

The bio-sensing activity of fluorescence based nanoprobes is one of the most significant aspects to scrutinize the analytical pursuance in modern security and lateral flow assays. Herein, potent transmogrification of waste cigarette tobacco into fluorescent carbon quantum dots (CQDs) has been achieved by calcination approach. The waste transformation to CQDs holds diverse benefits, comprising high quantum yield, low toxicity and scale up synthesis. The developed CQDs were able to identify tetracycline with phenomenal selectivity and sensitivity through fluorescence based method. The sensing mechanism was fully explored using Density Functional Theory (DFT) and Molecular docking studies. Governing features comprising tetracycline concentration, interfering studies, and real water analysis on the identification of tetracycline were also investigated. Along with, the prepared CQDs act as colorimetric probe, facilitating the detection of tetracycline with the naked eye. The lateral flow device was constructed for the on-site detection of tetracycline in real water samples. To the best of our knowledge, the present work represents a novel approach to designing CQDs and demonstrates their significant potential for application in anticounterfeiting measures and lateral flow devices. This work holds significant prospective as the prepared CQDs was fully utilized to its maximum usage in developing films and fluorescent anti-counterfeiting applications. Concisely, current work opens up distinctive opportunities for rapid on-site, real-time and visualized surveillance of tetracycline using CQDs prepared with a quite simple green approach.

Quantum dots: a next generation approach for pathogenic microbial biofilm inhibition; mechanistic insights, existing challenges, and future potential.

Quantum Dots (QDs) have emerged as versatile nanomaterials with origins spanning organic, inorganic, and natural sources, revolutionizing various biomedical applications, particularly in combating pathogenic biofilm formation. Biofilms, complex structures formed by microbial communities enveloped in exopolysaccharide matrices, pose formidable challenges to traditional antibiotics due to their high tolerance and resistance, exacerbating inefficacy issues in antibiotic treatments. QDs offer a promising solution, employing physical mechanisms like photothermal or photodynamic therapy to disrupt biofilms. Their efficacy is noteworthy, with lower susceptibility to resistance development and broad-spectrum action as compared to conventional antibiotic methods. The stability and durability of QDs ensure sustained biofilm activity, even in challenging environmental conditions. This comprehensive review delves into the synthesis, properties, and applications of Carbon Quantum Dots (CQDs), most widely used QDs, showcasing groundbreaking developments that position these nanomaterials at the forefront of cutting-edge research and innovation. These nanomaterials exhibit multifaceted mechanisms, disrupting cell walls and membranes, generating reactive oxygen species (ROS), and binding to nucleic materials, effectively inhibiting microbial proliferation. This opens transformative possibilities for healthcare interventions by providing insights into biofilm dynamics. However, challenges in size control necessitate ongoing research to refine fabrication techniques, ensure defect-free surfaces, and optimize biological activity. QDs emerge as microscopic yet potent tools, promising to contribute to a brighter future where quantum wonders shape innovative solutions to persistently challenging issues posed by pathogenic biofilms. Henceforth, this review aims to explore QDs as potential agents for inhibiting pathogenic microbial biofilms, elucidating the underlying mechanisms, addressing the current challenges, and highlighting their promising future potential.

Carbon quantum dots/UiO-66@polysulfone porous microspheres fabricated via pickering emulsion template for pollutant removal

The advancement of sophisticated photocatalytic materials for environmental amelioration has become increasingly imperative in the context of persistent organic pollutants in aqueous effluents. The amalgamation of metal-organic frameworks (MOFs) with nanocomposite constituents has demonstrated promising prospects in augmenting photocatalytic efficiency. Nevertheless, obstacles persist in the realms of optimizing photon absorption and the segregation of electron-hole pairs. The application of carbon quantum dots (CQDs) within this sphere, particularly in synergy with amino-functionalized MOFs such as UiO-66-NH2, remains underexplored. In this study, we elucidate the synthesis of UiO-66@Polysulfone porous microspheres, augmented by CQDs, employing an innovative Pickering emulsion template approach for the photocatalytic degradation of tetracycline. Our findings reveal that this composite material not only manifests a distinctive hollow microsphere architecture, contributing to an elevated specific surface area, but also markedly enhances the degradation efficacies of both methylene blue and tetracycline under visible light irradiation. Moreover, this research accentuates the material's exceptional recyclability and stability, highlighting its potential as a sustainable and efficacious solution for the remediation of wastewater and organic pollutant degradation.

One-Pot Hydrothermal Method Preparation of Cerium-Nitrogen-Codoped Carbon Quantum Dots from Waste Longan Nucleus as a Fluorescent Sensor for Sensing Drug Rifampicin.

Currently, the large-scale application of carbon quantum dots (CQDs) is usually limited by their low quantum yield and detection limit. Herein, the abandoned longan nucleus was used as a carbon source to synthesize cerium-nitrogen-codoped carbon quantum dots (Ce/N-CQDs) with strong luminescence intensity. In this work, the fluorescent properties and fluorescent quantum yield of CQDs may be improved by the single cerium-doped carbon quantum dots (Ce-CQDs) and the single nitrogen-doped carbon quantum dots (N-CQDs). Nevertheless, the Ce/N-CQDs exhibited intense fluorescence with a high quantum yield. Compared with CQDs, the quantum yield of Ce/N-CQDs was significantly increased from 5 to 32% and showed high photostability and good water solubility. The Ce/N-CQDs can be used for the direct detection of rifampicin (RFP) in human serum. The concentration demonstrated a good linear relationship in the range of 1.0 × 10-7-9.0 × 10-6 mol/L, with a detection limit of 9.6 × 10-8 mol/L.

Carbon quantum dot-induced developmental toxicity in Daphnia magna involves disturbance of symbiotic microorganisms

With the increasing synthesis and application of carbon quantum dots (CQDs), their prevalence as pollution in water environments has increased. However, the toxic effects of CQDs on aquatic organisms are unclear, and their environmental safety must be evaluated. Herein, Daphnia magna was used as a model organism to explore the developmental toxicity of CQDs under a full life-cycle exposure. It was found that the feeding rate and offing number of D. magna decreased with increasing CQD concentration, and the body length of D. magna showed a trend of first increasing and then decreasing. These results indicated that long-term exposure to CQDs has evident toxic effects on D. magna development. Symbiosis analysis showed that the composition of the symbiotic microbial community of D. magna was disturbed by CQDs. The abundance of microorganisms involved in the immune response of D. magna such as Rhodobacter, decreased; those involved in the inflammation such as Gemmobacter, increased; and those involved in the nitrogen cycle, such as Hydrogenophaga and Paracoccus, decreased. When D. magna was subjected to environmental pressure, host-microflora interactive immune regulation was induced. The abundance of probiotics in D. magna, such as Rhodococcus, increased in response to environmental pressure. The results of KEGG function prediction showed that the abundance of symbiotic microorganisms involved in energy absorption and metabolism was affected by CQDs. In addition, the correlation analysis showed that there was a correlation between the changes in the symbiotic microbial community and the damage to D. magna after exposure to CQDs. Thus, it is appealed that as a potential environmental pollutant, CQDs have aquatic environmental risks, and their safe application deserves attention.

Synthesis and applications of carbon quantum dots derived from biomass waste: a review

Synthesis and applications of carbon quantum dots derived from biomass waste: a review

Positive responses and mechanisms of nitrifying sludge to carbon quantum dots: reactor performance, microbial behavior, and antioxidant defense.

Extensive application of carbon quantum dots (CQDs) enlarges its concentration in sewage treatment system. The response of nitrifying sludge to CQDs after long-term exposure was investigated. Results showed that CQD concentrations of 0-100mg/L presented positive effect to enzymes involved in nitrification, accelerating NH4+-N degradation and NO2--N transformation. The oxidation rate of NO2--N was significantly improved from 3.14 to 7.91mg/(L h) under the stress of 100mg/L CQDs. Besides, CQDs stimulated the production of sludge biomass and kept the stability of sludge settleability. Additionally, CQDs were mainly captured by loosely bound extracellular polymeric substances, reducing aromatic-like protein. Microbes alleviated CQD stress by secreting tryptophan-like protein and polysaccharides. After few CQDs entered cells, intracellular antioxidant defense was activated. Total antioxidant capacity level was heightened at least 31%. The activities of superoxide dismutase and catalase were enhanced at relatively low and high CQD concentration levels. Hence, microbial metabolic pathways, microbial community, and nitrifying bacteria were not significantly affected by CQDs. The findings of this work provide new insight for understanding the environmental implication of CQDs in the biological treatment system.

Biomass solvothermal treatment methodologies to obtain carbon quantum dots: A systematic review

The application of carbon quantum dots (CQDs) in many systems is increasing due to their properties, such as nanoscale size, photoluminescence, and surface functional groups. This systematic review aims to analyze whether there is a relationship between the synthesis parameters and the final optical, morphological, and compositional characteristics of the material. Following PRISMA guidelines, the systematic review was performed in the Scopus database to identify the main articles synthesizing CQDs from vegetal biomass. Out of a total of 182 research articles found, 72 met the inclusion parameters. In all the cases, the authors characterized the CQDs using different analytical techniques. Among several synthesis parameters identified, a couple of them were analyzed against material properties such as mean particle size and quantum yield, observing trends in agreement with results previously reported by other authors. In addition, all studies confirmed that solvothermal method is a suitable way to obtain CQDs for different applications.

Surficial amino groups coupling induced concentration-dependent fluorescence and fluorescence quantum yield of nitrogen-dopped carbon quantum dots via efficient charge transfer.

Modification of surficial functional groups among carbon quantum dots (CQDs) has been considered an efficient approach to regulate the fluorescence emission of CQDs. However, the mechanism of how surficial functional groups affect fluorescence is vague which fundamentally limits the further applications of CQDs. Here we report the concentration-dependent fluorescence and fluorescence quantum yield of nitrogen-dopped carbon quantum dots (N-CQDs). At high concentrations (≥0.188g/L), fluorescence redshift occurs accompanied with decrease in fluorescence quantum yield. Fluorescence excitation spectra and HOMO-LUMO energy gaps calculations show that energy levels of excited states of N-CQDs are relocated via the coupling of surficial amino groups among N-CQDs. Furthermore, electron density difference maps and broadened fluorescence spectra obtained from both experimental measurement and theoretical calculation further confirm that the coupling of surficial amino groups dominates the fluorescence property and verify the formation of charge-transfer state of N-CQDs complex at high concentrations which provides pathways for efficient charge transfer. Given that charge-transfer state induced fluorescence loss and fluorescence spectra broadening are the typical characteristics of organic molecules, CQDs exhibit the optical properties of both quantum dots and organic molecules.

Synthesis and Application of Carbon Quantum Dots Derived from Carbon Black in Bioimaging.

Carbon quantum dots (CQDs) are a new type of fluorescent QDs that consists mainly of carbon atoms. In this research, CQDs were synthesized through harsh oxidizing conditions applied on carbon black and subsequent N-doping using hexamethylenetetramine (Hexamine) and polyethyleneimine (PEI). The synthesized CQDs were characterized using FTIR, AFM, UV-Visible spectroscopy, photoluminescence (PL) spectroscopy, and fluorescence imaging respectively. The AFM images showed that the dots are in the range of 2-8nm. N-doping of the CQDs increased the PL intensity. The PL enhancement for the CQDs that were N-doped with PEI was higher compared to those N-doped with hexamine. The shift in PL by changing the excitation wavelength has been attributed to the nano-size of the CQDs, functional groups, defect traps, and quantum confinement effect. The in vitro fluorescence imaging revealed that N-doped CQDs can internalize into the cells and be used for fluorescent cell imaging.

Potential Application of Carbon Quantum Dots (CQD) Synthesis from Rice Husk Waste Composite as Advanced Solar Cells to Increase Photon Energy Absorption in Maximizing Solar Panels Power Output Production

The increase in national energy consumption has forced us to intensify renewable energy utilization. Solar panel is one optional answer for that purpose. Unfortunately, the product resistance and photon absorption from silicon-based solar cells are still not good enough. Carbon quantum dots (CQD) could be an alternative advanced material that can be utilized to maximize the performance of solar panels. Therefore, researchers are interested in finding out how to manufacture CQD from the synthesis of rice husk waste composite as an advanced solar cell and analyze its potential to maximize solar panel photon energy absorption. Researchers use mixed study that applies literature review methods (as part of the descriptive research aspect) and causal comparative research methods (as part of the quantitative aspect). Based on previous research, rice husk waste was pre-processed by washing using de-ionized water (DI water) to remove residue, then baked and blended into powder, and cleaned using HCl as impurities remover. The hydrothermal process was carried out at 190 oC for 12 hours to synthesize CQD which functioned by amino and carboxyl. For further purification, CQD was dialyzed against DI water in cellulose. Super-dense material due to quantum level compression, makes CQD have a higher resistance when compared to silicon as solar cells. In addition, the absorption of photon energy that can be done by CQD solar cells has a higher percentage when compared to conventional solar cells. However, in this paper, the researchers did not make CQD and only analyzed through modeling which became the research gap in this paper.

Lychee-like SnO2 hollow microspheres sensitized by carbon quantum dots for high-sensitivity ethanol sensor

In this work, the application of carbon quantum dots as known as CQDs for ethanol detection is pioneered, and a multi-fold improvement in gas sensor performance is achieved through the unique electron transport mechanism of carbon quantum dots. The lychee-like SnO2 hollow microspheres and CQDs are prepared by a solvent heat method. The composites are assembled by rapid grinding, ultrasonication, and stirring. The minimum detection limit is 500 ppb. The response/recovery time of the best mass percentage composite is 9 s/16 s to ethanol at 100 ppm with an optimum working temperature of 216℃ in the target gas-sensitive test. Such a fast response speed improvement is ascribed to the excellent electron transfer efficiency of the 5 nm diameter carbon quantum dots (CQDs).

Zr, N-Co-Doped Carbon Quantum Dot Crosslinking Agents for Use in Fracturing Fluids

To further improve the performance of the fracturing fluid, the Zr, N-co-doped carbon quantum dot nano-crosslinking agent was synthesized by the hydrothermal method to solve the problems of easy agglomeration, instability, and gel breaking after crosslinking of the conventional polyacrylamide fracturing fluid crosslinking agent. The crosslinking agent has good stability and multiple crosslinking sites, as well as can be crosslinked with anionic polyacrylamide (HPAM) solution to form a high-strength hydrogel fracturing fluid. Moreover, it can be used as a nano-fluorescent tracer to test the flowback rate of fracturing fluid. The fracturing fluid composed of 0.3 wt % HPAM and 0.8 wt % crosslinking agent was named as Zr-CDG. At 180 °C, the viscosity of Zr-CDG remains above 180 mPa·s after shearing for 2 h, indicating that Zr-CDG has excellent temperature tolerance and shearing resistance. The residue is only 169 mg/L after gel breaking, which means low damage to the formation. Finally, the backflow process of fracturing fluid is simulated by core displacement. According to the good luminescence of the carbon quantum dot nano-crosslinking agent, the flowback rate of the fracturing fluid is calculated. It shows that the carbon quantum dot nano-crosslinking agent also has the role of fracturing fluid tracer. The results show that the properties of the prepared carbon quantum dot nano-crosslinking agent are more stable, and the performance of the crosslinked fracturing fluid system is greatly improved, which points out a direction for the application of carbon quantum dots.

Reservoir Adaptability Evaluation and Application Technology of Carbon Quantum Dot Fluorescent Tracer

This study investigates the application of carbon quantum dots as tracers in inter-well connectivity monitoring. A new laboratory-made water-soluble carbon quantum dot fluorescent tracer (CQD-W) was studied using 3D fluorescence characterization, structural characterization, reservoir suitability evaluation, and core flow experiments. The experimental results showed that CQD-W has a size of about 2 nm, a minimum detection limit of 10−2 mg·L−1. It has good stability when the salinity is 200,000 mg·L−1, the concentration of Ca2+ is 1000 mg·L−1, the pH value is 1–9, and the temperature is 80 °C. Because CQD-W contains many functional groups, such as carboxyl and hydroxyl, it shows good water solubility and has a negative surface charge. In the process of formation flow, CQD-W has a small adsorption amount, high tracer resolution, and excellent injectivity and mobility, meaning it is less likely to cause reservoir damage. Through the study of this method, the application field of carbon quantum dots is broadened, and it is proved that the CQD-W fluorescent tracer has a high potential for application in the oil industry, laying the foundation for the popularization of this technology.

Current trends in carbon-based quantum dots development from solid wastes and their applications.

Urbanization and a massive population boom have immensely increased the solid wastes (SWs) generation and are expected to reach 3.40 billion tons by 2050. In many developed and emerging nations, SWs are prevalent in both major and small cities. As a result, in the current context, the reusability of SWs through various applications has taken on added importance. Carbon-based quantum dots (Cb-QDs) and their many variants are synthesized from SWs in a straightforward and practical method. Cb-QDs are a new type of semiconductor that has attracted the interest of researchers due to their wide range of applications, which include everything from energy storage, chemical sensing, to drug delivery. This review is primarily focused on the conversion of SWs into useful materials, which is an essential aspect of waste management for pollution reduction. In this context, the goal of the current review is to investigate the sustainable synthesis routes of carbon quantum dots (CQDs), graphene quantum dots (GQDs), and graphene oxide quantum dots (GOQDs) from various types SWs. The applications of CQDs, GQDs, and GOQDs in the different areas are also been discussed. Finally, the challenges in implementing the existing synthesis methods and future research directions are highlighted.

Properties and application of carbon quantum dots (CQDs) in biosensors for disease detection: A comprehensive review

Properties and application of carbon quantum dots (CQDs) in biosensors for disease detection: A comprehensive review

Progress on the luminescence mechanism and application of carbon quantum dots based on biomass synthesis.

With the continuous development of carbon-based materials, a variety of new materials have emerged one after another. Carbon Quantum Dots (CQDs) have succeeded in standing out from the crowd of new materials due to their better optical properties in biomedicine, ion detection, anti-counterfeiting materials and photocatalysis. In recent years, through the continuous exploration of CQDs, research scholars have found that the organic substances or heavy metals contained in traditional ones can cause irreversible harm to people and the environment. Therefore, the application of traditional CQDs in future studies will be gradually limited. Among various new materials, biomass raw materials have the merits of good biocompatibility, lower toxicity and green and environmental protection, which largely overcome the defects of traditional materials and have attracted many scholars to focus on the research and development of various biomass CQDs. This paper summarises the optical properties, fluorescence mechanisms, synthetic methods, functionalisation modulation of biomass CQDs and their relevant research progress in the fields of ion detection, bioimaging, biomedicine, biosensing, solar cells, anti-counterfeit materials, photocatalysis and capacitors. Finally, the paper concludes with some discussion of the challenges and prospects of this exciting and promising field of application.