Green-emitting carbon dots from Protocatechuic acid and branched PEI: A multifunctional platform for bioimaging and gene delivery.

Covalently modified high purity carbon nanodots for enhanced detection of arsenic.

Sustainable carbon nanodots from medicinal plants: Unlocking their biomedical and theranostic applications

Development of carbon nanodots from durian waste incorporated with first-row transition metals for efficient degradation of microplastics in oral care products

Drought is one of the major stress factors causing substantial yield losses in wheat production, and current agricultural practices often remain insufficient to enhance stress tolerance. In recent years, carbon nanodots have emerged as innovative nanomaterials in plant stress due to their high biocompatibility, low toxicity, and strong antioxidant properties. Carbon nanodots synthesized from phenolic-rich lignocellulosic wastes offer an economically and environmentally sustainable approach. In this context, although hazelnut shell, characterized by its high carbon and phenolic content, represents an ideal raw material, no study has investigated how carbon nanodots derived from this material modulate physiological and metabolic responses to drought stress in wheat. This study aimed to determine the holistic effects of hazelnut shell–derived carbon nanodots on gas exchange, PSII photochemistry, and phenolic metabolism of wheat seedlings exposed to PEG-induced drought stress. Wheat seedlings were treated with HNS-CNDs for 72 hours, followed by 48 hours of 10% PEG stress. Compared with PEG alone, the HNS-CND+PEG treatment increased photosynthetic rate by 83.8%, transpiration by 61.4%, stomatal conductance by 96.2%, and intercellular CO₂ concentration by 69.4%. Chlorophyll fluorescence measurements revealed increases of 6.7% in Fv/Fm and 12.3% in ΦPSII, whereas NPQ decreased by 52.8%. Phenolic analyses showed increases of 33.5% in gallic acid, 12.5% in pyrogallol, and 5.3% in (–)-epicatechin, along with decreases of 25.1% in vanillic acid, 59.7% in p-coumaric acid, 80% in chlorogenic acid, 48.8% in rutin, 20.6% in quercetin, and 22% in baicalein. Overall, the findings demonstrate that HNS-CNDs significantly enhance drought tolerance in wheat by restructuring photosynthetic capacity, stabilizing PSII photochemistry, and redirecting phenolic flux toward more energy-efficient antioxidant compounds.

To develop a safe, efficient, water-soluble, and targeted antibacterial substance for medical applications, we synthesized carbon dots using citric acid and urea as precursors by a solvothermal method. We then coupled the carbon dots and lysozyme by using a simple 1-ethyl-3-(3'-dimethylaminopropyl) carbodiimide-N-hydroxysuccinimide (EDC-NHS) coupling method. After coupling, the carbon dots exhibited improved water dispersibility with particle sizes ranging from 12 to 20 nm. Notably, the highest carbon dot concentration associated with cytotoxicity increased from 2.5 to 5 mg/mL when coupled with lysozyme, implying that coupling could enhance the biocompatibility of carbon nanodots. Furthermore, coupled carbon dots extended the effective inhibition time against Streptococcus mutans from 12 to 36 h, compared to carbon dots alone. The improved biocompatibility and prolonged effective antibacterial duration highlight the potential of lysozyme-coupled carbon dots as a safe, efficient, and water-soluble antibacterial agent for a variety of oral healthcare and medical applications.

Red light plays a crucial role in plant growth. However, the lack of functional materials suitable for red light emission under ultraviolet excitation limits the ability of ultraviolet light sources for greenhouse illumination. Solid-state carbon dots, serving as alternatives to rare-earth phosphors, typically achieve red emission by narrowing their bandgap through defect introduction, an increased particle size, and enhanced conjugation. However, bandgap reduction often induces a red-shift of the excitation wavelength. Therefore, the excitation spectrum of solid-state red-emitting carbon dots is currently mainly concentrated in the long-wavelength visible light region, which cannot meet the needs of ultraviolet light-emitting LEDs in the field of greenhouse illumination. To address this, we designed core-shell structured solid-state carbon nanodots, leveraging synergistic effects between the core and shell layers to achieve highly efficient red light emission. When excited with ultraviolet light (362 nm), the carbon nanodots emit red fluorescence (619 nm), with a Stokes shift as large as 257 nm. Furthermore, a light conversion film was fabricated by compositing the carbon nanodots with PMMA and then integrated with a UV-LED as a light source for indoor plant cultivation, effectively promoting healthy plant growth. In summary, the solid-state red-emitting carbon nanodots synthesized in this study exhibit broad application prospects in both ultraviolet light utilization and plant illumination fields.

Pinus pinea L. bark residues were utilized for the environmentally friendly synthesis of PP300-3 carbon nanodots (synthesized via pyrolytic treatment at 300 °C for 3 hours). Comprehensive structural characterization employing high-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) revealed a hybrid nanostructure comprising crystalline graphitic domains and amorphous carbon regions. This heterogeneous structure provides excellent photoluminescent properties with a quantum yield of 3.8%. Photoluminescent characteristics were investigated through wavelength-dependent optical studies, revealing optimal photon emission efficiency at 320 nm. Screening experiments with thirty-three metal ions demonstrated that Fe3+ exhibited high selectivity. Although five metal ions (Au3+, Bi3+, Pd2+, Pt2+) caused some fluorescence quenching, only Fe3+ demonstrated a linear dose-dependent response suitable for quantitative analysis. With excellent analytical performance (R 2 = 0.9926, RSD < 2%, LOD = 35.43 µg L-1), a simple spectrofluorometric protocol for Fe3+ determination was developed and validated in real water samples, achieving 99.56% recovery rates. Antioxidant evaluation using FRAP, CUPRAC, and DPPH assays demonstrated significant free-radical scavenging efficiency. Low SC50 concentrations (4.36 ± 0.92 mg mL-1) indicate robust electron-transfer capacity and valuable antioxidant activity. In conclusion, PP300-3 carbon nanodots represent a versatile platform material with simple synthesis, environmentally friendly production, excellent analytical performance, and significant antioxidant activity, making them suitable for environmental monitoring, water quality control, and biomedical research.

Oxidative pathway of quenching of the luminescence of carbon nanodots (PD-CNDs) in the presence of picric acid (PA).

Progress of stimuli-responsive fluorescent materials with time-dependent optical properties for information anti-counterfeiting and encryption.

Natural quercetin-derived carbon nanodots for dual antibacterial and anti-inflammatory therapy against bacterial infections.

Biomass-derived carbon nanodots with pH-operated LAMP switching for ultrasensitive DNA detection

Activated carbon nanodots derived from date palm and oil palm trees for designing effective capacitive deionization electrodes

Abstract 2D MXenes have emerged as a cutting-edge family of materials for next-generation supercapacitors, distinguished by their metallic conductivity, adaptive surface chemistry, and precisely tunable layered architecture. These materials have emerged as promising materials for energy storage in supercapacitors; however, challenges such as restacking and structural degradation have motivated the development of composites, which can synergistically enhance electrochemical performance and stability. This review elucidates the charge storage mechanisms in MXene-based composites, including the formation of electric double layers, pseudocapacitance, and ion intercalation. It also highlights the charge storage mechanisms involved in MXene-based composites, mainly including carbon nanostructures, inorganic materials, and organic matrices. MXene–carbon hybrids with graphene, carbon nanotubes (CNTs), carbon nanodots enhance ion/electron transport and prevent restacking; MXene–inorganic hybrids with metal oxides, metal-organic frameworks (MOFs), etc., provide abundant redox sites and structural stability; and MXene–organic composites with polymers or cellulose offer mechanical flexibility, processability, and environmental compatibility while maintaining excellent electrical performance. The review also discusses current challenges such as oxidation, aggregation, and interface instability, proposing strategies such as interfacial engineering, surface functionalization, and 3D structural design. By bridging compositional innovation with electrochemical insight, this article presents a holistic framework for the development of next-generation MXene-based supercapacitors that combine high energy density, long-term durability, and mechanical adaptability.

To tackle the challenges posed by nutrient deficiencies in chilli cultivation, a cutting-edge laboratory experiment was conducted during the Rabi season of 2022–23 at SRTC, PJTSAU, Hyderabad, exploring the potential of nutrient-doped carbon nanodots (CNDs). Seventeen treatments incorporating varying levels of zinc, iron, copper, manganese, calcium, and boron were examined to assess their impact on seed vigour, seedling dry weight, and field emergence. The results indicated that iron-doped (T4) and manganese-doped (T8) treatments notably enhanced seed vigour by up to 6%, maintained higher seedling dry weight up to 0.020 g, and improved field emergence up to 62% after 18 months of storage. In contrast, higher concentrations of calcium (T11) and boron (T14) were less effective. These findings demonstrate that nutrient-doped carbon nanodots can serve as a novel solution to enhance seed vigour and field emergence, ultimately improving chilli seed quality.

Cancer remains a significant global health challenge, necessitating advancements in therapeutic strategies to overcome the limitations of conventional treatments, including resistance development and adverse side effects. Baicalein, a naturally derived flavonoid with potent anticancer, antioxidant, and antiinflammation properties, has shown great promise but its usage in clinical application limited by poor aqueous solubility and low bioavailability. Nanotechnology-based drug delivery systems, such as nanoparticle carbon nanodots (CDs), present a promising solution to improve drug stability, solubility, and targeted delivery. This study aimed to develop, characterize, and evaluate the stability of baicalein-loaded carbon nanodots (Bai-CDs) as a novel therapeutic delivery system. CDs were synthesized via the pyrolysis of citric acid and subsequently loaded with baicalein under optimized conditions (pH 7.4, 2:1 ratio). The resulting Bai-CDs exhibited an increase in particle size (from 10 nm to 23 nm) upon loading, with successful physical interactions confirmed by Ultraviolet-visible (UV-Vis) and Fourier Transform Infrared (FTIR) spectroscopy. The loading capacity (LC) and adsorption efficiency (AE) of baicalein were found to be 37% and 74 %. Stability assessments demonstrated the enhanced robustness of Bai-CDs under varying pH and ionic conditions, particularly in acidic environments. These findings confirm the successful design and characterization of Bai-CDs, offering improved stability and paving the way for their application as a nanocarrier system to enhance baicalein’s bioavailability and therapeutic efficacy. This study underscores the potential of Bai-CDs as a promising strategy for advanced drug delivery in cancer therapy.

The accumulation of organic waste can cause various diseases and environmental pollution. One of the diseases caused by this is Dengue Hemorrhagic Fever (DHF). Organic waste such as durian peel waste contains carbon, which can be processed into carbon nanodots (C-dots). The C-dots from durian peel waste can be used as a basic ingredient for mosquito repellent spray because durian peel contains essential oils, flavonoids, saponins, and tannins, which are toxic to mosquitoes. The synthesis of C-dots can also reduce environmental pollution due to durian peel waste. The purpose of this study was i) to prepare and characterize C-dots from durian peel waste using UV-Vis and PSA tests, and ii) to identify the effect of the C-dots solution in a mosquito repellent test in order to determine the ability of the anti-mosquito spray. This was an experimental study on the preparation of C-dots from durian peel waste using the two-steps low heating (TSLH) method. The anti-mosquito spray was made of 3 ratios of C-dots mass to distilled water volume, i.e.: (0.1 g : 200 ml); (0.2 g : 200 ml); and (0.3 g : 200 ml). Based on the results of the UV-Vis and PSA characterizations, it was found that the absorption peaks of the C-dots were at the wavelength interval of 288–332 nm and the sizes of the C-dots were 178.6 nm (69.3%) and 54.1 (20%). The mosquito repellent test showed that the anti-mosquito spray could repel and eradicate mosquitoes at the best ratio of (0.1 g C-dots : 200 ml of distilled water) with the highest mosquito’s mortality of 11 mosquitoes in 17 minutes and 29 seconds. This proves that the C-dots from durian peel waste can be used as an anti-mosquito spray.

The development of mechano-responsive room-temperature phosphorescent (RTP) materials with reversibility and durable memory stress-recording capability remains a critical challenge, particularly under extreme operational conditions where covalent bond-dependent systems often suffer from irreversible degradation. Herein, a hydrogen-bond-induced dynamic supramolecular confinement framework is constructed to achieve cyclodextrin-trapped carbon nanodots (CNDs) with reversible and memorable mechano-responsive RTP. Mechanical stress disrupts the metastable hydrogen-bond network and weakens phosphorescence via enhanced non-radiative decay of triplet excitons. Remarkably, the system exhibits a recovery of RTP intensity through ultrasonic reconstruction of the rigid cyclodextrin matrix. When deployed in aerospace structural health monitoring, the CND-embedded film visualizes stress distribution in wings under sudden stress events through RTP weakening. This work establishes a non-destructive monitoring paradigm for an extreme aerospace environment.

White phosphorescent materials are highly desirable for delayed lighting and advanced display applications; however, their development is hindered by time-dependent spectral changes and low efficiency. Herein, we report bright and long-lived white phosphorescence from carbon nanodots (CNDs) achieved by synchronizing excited-state lifetime engineering yielding white phosphorescent CNDs with a lifetime of 800 ms and a quantum efficiency of 27.9%. A secondary carbonization strategy synchronizes multiple emission centers, enabling stable white phosphorescence over 6 s, tunable correlated color temperature (4400-7990 K), and CIE coordinates (0.29, 0.32) to (0.36, 0.34). Moreover, integration of these CNDs into a light emitting diode (LED) demonstrates delayed white emission with suppressed flicker under alternating-current excitation, providing eye-friendly illumination. Programmable delayed LED arrays reconstruct temporally fragmented signals into coherent images. This work demonstrates a robust strategy for bright and long-lasting white phosphorescent materials, laying the foundation for advanced delayed lighting and programmable display applications.

IntroductionCarbon dot nanoparticles (CNDs) are widely regarded as biocompatible agents for cellular imaging due to their strong fluorescence and ease of synthesis. However, their biological effects remain insufficiently characterized.MethodsWe synthesized carbon nanodots (E-CNDs) using a microwave-assisted method with citric acid and ethylenediamine. Their intracellular distribution and potential impact on triple-negative breast cancer (TNBC) cells were investigated.ResultsAfter 16 hours of incubation with E-CNDs (up to 0.8 mg/mL), imaging revealed strong perinuclear localization, moderate mitochondrial presence, and no detectable nuclear signal. These observations supported their use in intracellular imaging and motivated further analysis of their biological effects. While CCK-8 assays showed no significant cytotoxicity across concentrations, molecular analysis revealed dose-dependent downregulation of glucose-6-phosphate dehydrogenase (G6PDH) and upregulation of procaspase 3, aligning with increased apoptotic activity detected by Annexin V/PI staining.ConclusionThese results show that although E-CNDs appear non-toxic by standard viability assays and function effectively as imaging agents, they also trigger measurable molecular and apoptotic responses. This underscores that cell viability alone is insufficient to assume biocompatibility. More detailed molecular and functional assessments are needed to establish reliable safety profiles, which are critical for the safe design and evaluation of nanomaterials in biomedical applications.