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Luminescent materials with time‐resolved dynamic discoloring afterglow (TDDA) hold significant potential for applications in anti‐counterfeiting and data encryption. However, the afterglows coming from organic systems are usually unidentifiable due to their shorter durations (less than 10 s). Achievement of long‐lasting and visually discernible TDDA remains highly desirable but challenging. In this work, the TDDA duration is successfully extended from less than 10 s to minutes by engineering the luminescent centers of carbon dots (CDs) and introducing deep trap‐states in a composite of CDs and carbon nitrides (CNs) (named Y‐CDs@CN). It is confirmed that the regulation of luminescent centers in CDs containing both C═N and C═O bonds is responsible for the color changes during TDDA from yellow to green. Moreover, the generation of deep trap states is found to be significant for prolonging the afterglow duration to minutes level through converting room temperature phosphorescence into long persistent luminescence, thus making the entire dynamic discoloring process being easily recognized to naked eyes. Furthermore, the afterglow of Y‐CDs@CN can also be excited by blue light and even using white light of a cell phone. To harness these characteristics, potential applications of Y‐CDs@CN for portable anti‐counterfeiting and multidimensional information encryption are primarily investigated. [ABSTRACT FROM AUTHOR]

Gd3+- free carbon dots (CDs) were synthesized by one-step solvothermal method using urea, citric acid and 3-(trifluoromethyl)aniline as precursors. Additionally, Gd3+-doped CDs were prepared by incorporating gadolinium chloride (Gd3+ ions) into the synthesis. Size selection of the purified CDs was achieved through filter membranes ranging from 3 kDa to 100 kDa. The chemical composition and optical properties of the obtained samples were characterized by Energy dispersive X-ray (EDX), Fourier-transform infrared spectroscopy (FTIR), Dynamic Light Scattering (DLS), proton relaxation time measurements, Ultraviolet–visible (UV-vis) and fluorescence spectroscopies. A comparative analysis revealed a strong size-dependent behavior in the optical properties of both Gd3+-doped and Gd3+-free CDs. Furthermore, in vitro tests confirmed the non-cytotoxicity of Gd3+-doped CDs, indicating their potential applicability in biomedicine for magnetic resonance imaging (MRI) and red fluorescence-based cell and tissue imaging. [ABSTRACT FROM AUTHOR]

Ethylene glycol (EG) is a widely used material, but its vapor is harmful to human health already in low concentrations. Thus, highly sensitive EG gas sensors are urgently needed. Herein, a series samples of ZnO and carbon dots (CDs) were synthesized at different ratios through a simple mechanical grinding method. The senor made using ZnO/CDs2 exhibits an ultra-high response (Ra/Rg) to 100 ppm EG up to 2798, 1378 and 467, and extremely low detection limit as low as 21 ppb, 13 ppb and 2 ppb, under UV light, visible light, and infrared light, respectively, as well as excellent repeatability and long-term stability. Especially, under UV light irradiation, the response of ZnO/CDs2 to 100 ppm EG is 24 times that of pure ZnO (Ra/Rg = 114.7), and more than 71 times that of 9 other gases. The outstanding gas sensing performance of ZnO/CDs2 can be attributed to the excellent light response ability of CDs at first, which greatly enriches the electron concentration in ZnO/CDs under light irradiation. Furthermore, the photo-induced electron transfer (PET) property of CDs and the p-n heterojunction formed at the interface between ZnO and CDs play a key role in rapid electron transport and transfer, avoiding a large number of electron hole recombination. [ABSTRACT FROM AUTHOR]

Serendipitously discovered, carbon dots (CDs) have attracted significant attention as a potential contrast agent for photoacoustic imaging (PAI) in the biomedical sector. CDs play an essential role in PAI, contributing significantly to the early detection of diseases and monitoring treatment progress, particularly in tumor imaging. This review emphasizes the role of CDs in the domain of PAI, highlighting their characteristics like biocompatibility, enhanced spatial resolution, optical absorption in the NIR region, and facile surface functionalization for tumor‐ targeted imaging. The study explores the use of CDs for enhancing spatial resolution in PAI for improved detection and visualization of tumors in organs such as the breast, cervical, liver, gastrointestinal, skin, cardiovascular system, nervous system, and others. Challenges associated with PAI, such as optimizing the signal‐to‐noise ratio and ensuring stability under physiological conditions, have also been discussed. [ABSTRACT FROM AUTHOR]

Dynamic organic room‐temperature phosphorescence (RTP) materials are highly promising for various applications. However, developing photo‐responsive RTP systems with simple fabrication, high reversibility, and visible‐light responsiveness presents a significant challenge. Herein, in situ embedding of boron‐doped carbon dots (B‐CDs) in amorphous polymer (pPBA) is achieved by a two‐step polymerization and carbonization process. Impressively, the B‐CDs@pPBA composite exhibits visible‐light‐activated ultralong RTP with full reversibility and a lifetime on–off ratio exceeding 280. By correlating photophysical properties with structural characterization results, it is concluded that photoinduced intensifying of the crosslinking between B‐CDs and pPBA is responsible for the dynamic RTP. More interestingly, the B‐CDs@pPBA film is found to display bending actuation and reversible deformable behavior upon light exposure. Finally, potential applications of such photo‐responsive systems in programmable information storage and encryption are demonstrated. This research may pave a new way for the development of dynamic RTP nanomaterials and promote their use in a wide range of promising applications. [ABSTRACT FROM AUTHOR]

The scientific community is actively engaged in the development of innovative nanomaterials with broad‐spectrum virucidal properties, particularly those capable of producing reactive oxygen species (ROS), to combat upcoming pandemics effectively. The generation of ROS capable of inhibiting viral activity on high‐touch surfaces can prove an effective means of reducing pathogenic and viral infections, while avoiding the exacerbation of antibiotic resistance resulting from the extensive use of chemical disinfectants. Carbon dots (C‐dots), in particular, are a class of nanomaterials that under specific conditions is able to generate reactive species. They are, therefore, excellent candidates for fabricating light‐activated functional antiviral devices. Pro‐oxidant C‐dots have been developed via microwave synthesis using an amino acid, glycine (Gly), and 1,5‐diaminonaphtalene (DAN) as precursors. The formation of C‐dots has been obtained by reacting the precursors in microwave using two different acid catalysts, H3BO3 or HCl. The HCl catalyst promotes the formation of a copolymer while using H3BO3 the precursors preferentially self‐condense. The boron‐catalyzed samples have shown to contain radical centers whose intensity increases upon illumination by UV and also visible light. They also show the capability of generating singlet oxygen through energy transfer to oxygen molecules when irradiated. The C‐dots exhibit effective virucidal activity and have been tested in vitro using two different variants of SARS‐CoV‐2, the original strain, and Omicron. Antiviral C‐dots have been finally used to functionalize a model surface, inducing a strong virucidal activity against the SARS‐CoV‐2 coronavirus with both ultraviolet (UV) and visible (VL) light. [ABSTRACT FROM AUTHOR]

A novel portable cotton swab based on nitrogen-doped carbon dots (NCDs) for Al3+ detection was constructed for the first time. NCDs with bright green fluorescence were prepared by hydrothermal method with phenylhydrazine hydrochloride and 3-hydroxy-2-naphthoic acid hydrazide as precursors. The surface of NCDs was exposed to abundant functional groups (such as amino, carboxyl, hydroxyl, etc.), which was helpful for the formation of complexes between NCDs and Al3+. In the presence of Al3+, the aggregation of NCDs obviously induced their fluorescence enhancement due to the aggregation-induced emission (AIE) of NCDs. Furthermore, the quantum yield (QY) of NCDs was enhanced by 12 times with Al3+, and the fluorescence lifetime was increased by 7.54 ns. The fluorescence intensity was linearly correlated with the concentration of Al3+ (2.5–300 μM), and the limit of detection was 0.76 μM. Moreover, for the portable way, cotton swabs were successfully employed to construct the sensors for the detection of Al3+ in food samples. This proposal has potential for the application in food analysis. [ABSTRACT FROM AUTHOR]

An economically viable and greener approach is introduced to fabricate red emissive carbon dots (R@CQDs) via employing hydrothermal means on Hibiscus rosa-sinensis leaves as precursor source. The obtained R@CQDs displayed excitation-dependent behavior, with high aqueous stability, quantum yield of 56%, and outstanding fluorescence aptitude under the conditions of varied range of ionic strength and pH (1–12). The fluorescence emission behavior of R@CQDs displayed selective turn off fluorescence response to tartrazine over other interfering species with a limit of detection of 0.09 µM and quantitation limit of 0.30 µM. Theoretical calculations employing density functional theory (DFT) were carried out to complement experimental findings and getting insights into the underlying mechanism governing the sensing of tartrazine. The developed sensor holds significant potential for tartrazine detection in real samples and offering wider prospective in the food safety assessment. [ABSTRACT FROM AUTHOR]

A new type of carbon dots (D-NCCDs) was synthesized by 3, 5-diaminobenzoic acid, N,N-dimethyl-o-phenylenediamine, and D-cysteine. The morphology and structure of D-NCCDs were investigated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and FT-IR spectra, and the chirality was characterized by circular dichroism. In the presence of hydrogen peroxide, the fluorescence of D-NCCDs at 487 nm (λex = 410 nm) showed great discrimination ability towards glutamine enantiomers. The ratio of fluorescence intensity (F/F0) to the concentration of D-Gln showed good linearity in the range 0.5–10 mM, with a detection limits of 0.11 mM. Meanwhile, the color of the solution gradually changed from light yellow to yellow–brown. The UV–Vis absorption ratio (A/A0) at 410 nm showed good linearity with the concentration of D-Gln in the range 0.5 to 20 mM; the detection limit is 7.7 μM. But the fluorescence and absorbance of D-NCCDs showed no significant change after the addition of L-glutamine. Thus, fluorescence and colorimetry dual-mode discrimination of glutamine enantiomers was achieved. The fluorescence enantioselectivity of Gln (FL-Gln/FD-Gln) is 1.62, and the colorimetric enantioselectivity of Gln (AD-Gln/AL-Gln) is 2.14. The chiral discrimination mechanism of D-NCCDs to Gln enantiomers was also investigated systematically. This work not only can discriminate glutamine enantiomers with high sensitivity and convenience, but also offers a new strategy for preparing new dual mode chiral nanoprobes. [ABSTRACT FROM AUTHOR]

A novel assay was developed based on a turn-off fluorescent probe using the in situ generation of carbon dots (CDs) by means of UV/H2O2 advanced oxidation of carbohydrates for the detection of bisphenol A (BPA) in food. Different parameters involved in the synthesis of CDs for the direct recognition of BPA have been optimised and a sensing mechanism is outlined. The presence of H2O2 during CD synthesis causes a fluorescence enhancement due to the action of highly oxidant HO· radicals formed throughout the photochemical reaction. Phenolic compounds such as BPA can be easily degraded by the UV/H2O2 oxidation process, acting as a HO· free radical scavengers. This results in a decrease in the fluorescence that can be related to the BPA concentration. Under optimal conditions, a detection limit of 15 µg/kg of BPA and a quantification limit of 46 µg/kg of BPA in food samples were obtained. The repeatability and reproducibility, expressed as relative standard deviation and obtained for two concentration levels (30 µg/kg and 200 µg/kg, n = 5), were less than 2.0% and 6.4%, respectively. The proposed procedure was applied to the analysis of five samples of canned foods (sweet corn, peas, mushrooms, cockles and natural tuna), obtaining concentrations in the range 29.8–49.9 µg/kg of sample. Recovery studies were conducted at two concentration levels (100 and 400 µg BPA/kg of sample), resulting in recoveries in the range 99–101%. Method validation against two certified reference materials was also successfully performed. The experimental results demonstrate that the novel approach is suitable for the detection and quantification of BPA in canned foods. [ABSTRACT FROM AUTHOR]

A novel fluorescent sensor based on silver nanoparticle-carbon dot composites (Ag@CDs) has been developed for the rapid and quantitative detection of aquatic bacteria. The sensor operates on the principle of plasmon-enhanced resonance energy transfer, where the fluorescence of CDs is quenched by Ag nanoparticles and restored upon bacterial interaction due to the generation of reactive oxygen species. The Ag@CDs exhibit a linear response to bacterial concentration over the range 7 × 104 ~ 4 × 107 CFU·mL−1, with a low detection limit of 4 × 104 CFU·mL−1. The fluorescence recovery is rapid, reaching maximum intensity within 5 min. The method demonstrates high selectivity, with minimal interference from common ions and compounds found in municipal and industrial wastewater. The Ag@CDs-based 96-well plate assay for quantitative measurement of bacteria was developed. The assay's performance was further validated through the analysis of real water samples, showing a recovery of 94.0 ~ 102% for domestic wastewater and 97.6 ~ 106% for industrial wastewater. Also, Ag@CDs-based test strips assay for semi-quantitation were developed for rapid in-field aquatic bacteria detection. Ag@CDs can be conveniently integrated into 96-well plates and test strips, providing rapid on-site aquatic bacteria testing. [ABSTRACT FROM AUTHOR]

Novel boron-doped carbon dots (BCDs) with extended afterglow characteristics were synthesized via a one-step solvothermal method using acrylamide, sulfosalicylic acid, and sodium tetraborate as protective matrices. The presence of boron from sodium tetraborate introduced an empty orbital, allowing it to form a more extended conjugated system with adjacent oxygen atoms, thereby lowering the energy level of the lowest unoccupied molecular orbital in the system. The phosphorescence emission of these BCDs exhibits a red shift over time from 450 to 500 nm. These BCDs have been effectively utilized to produce anti-counterfeit phosphorescent powder. Additionally, the BCDs display optimal fluorescence excitation at 330 nm and optimal emission at 420 nm. They demonstrate a detection limit for ciprofloxacin hydrochloride of 37 nM in the 1-100 µM concentration range and 26 nM in the 100-210 µM range. This fluorescence detection is governed by an inner filter effect. Real sample testing further confirms that these BCDs serve as excellent sensors for ciprofloxacin hydrochloride. [ABSTRACT FROM AUTHOR]

As a class of carbon-based nanomaterials, carbon dots (CDs) have gained a lot of interest for a variety of applications. They offer distinctive optical, chemical, and structural characteristics along with favourable attributes such as low cost, availability of abundant functional groups, remarkable chemical inertness, high stability, exceptional biocompatibility, and ecofriendliness. This review discusses synthesis methods, structural characteristics, and surface modifications of CDs, specific for pathogen detection. Furthermore, it delves into the mechanisms that govern the interaction between pathogens and CDs. In addition, the study explores the use of CDs in a number of detection modalities, such as optical, electrochemical, and electrochemiluminescence, emphasising real-time pathogen monitoring. Moreover, both the challenges and opportunities related to the application of CDs-based detection and imaging methods are highlighted in field and clinical contexts. [ABSTRACT FROM AUTHOR]

Room temperature phosphorescent carbon dots (NCCDs@SiO2) were obtained by encapsulating hydrothermally synthesized CDs in a dense Si-O network structure after high-temperature calcination using silica as the matrix. This can avoid the quenching effect of dissolved oxygen in water and has a phosphorescence lifetime of up to 2.41 s. Using the phosphorescence property of NCCDs@SiO2, a phosphorescence quenching sensor was developed for the sensitive and selective detection of thiram with the assistance of Cu2+. Cu2+-thiram complexes led to a rapid phosphorescence quenching of NCCDs@SiO2 within 30 s through the inner filter effect. The linear range of phosphorescence for thiram was 0.5–100 µM with a detection limit of 0.121 µM. The proposed method was able to detect thiram in real samples and was validated by high-performance liquid chromatography (HPLC) confirming the potential of this phosphorescence sensing method for thiram detection. This work opens up a new avenue for the detection of thiram residues in fruits and vegetables and also provides a new idea for the design of a rapid detection platform using other room temperature phosphorescent materials. [ABSTRACT FROM AUTHOR]

Plant-derived carbon dots (P-CDs) are gaining attention in environmental remediation due to their cost-effectiveness, availability, and lower toxicity compared with chemically synthesized carbon dots. This review comprehensively examines the recent advancements in the synthesis and application of P-CDs, with a particular emphasis on their efficacy in the sensing of heavy metals, which are among the most pervasive environmental contaminants. A detailed comparative analysis is presented by evaluating the performance of P-CDs against their chemically synthesized counterparts based on key parameters, such as optimal operating conditions and detection limits. Furthermore, sensing the potential of P-CDs towards every heavy metal ion has been discussed with in-depth mechanistic insights. Additionally, this review explores the industrial applications and future directions of P-CDs. This review provides a comprehensive analysis of -P-CDs for heavy metal sensing, aiming to enhance their sensitivity and selectivity toward heavy metal ions. [ABSTRACT FROM AUTHOR]

Zinc‐based batteries are emerging as the most promising candidates for large‐scale energy storage devices due to their low cost, high safety, and long‐term storage. However, zinc‐based batteries encounter challenges stemming from undesirable side reactions and zinc dendrites on the anode, as well as dissolution on the cathode. Owing to their extremely small size, substantial surface functional groups, and adjustable structure, carbon dots (CDs) present considerable benefits in augmenting coulombic efficiency, expanding cycle life, and enhancing the rate functionality of zinc‐based batteries. Herein, this review delves into the surface modification and morphological regulation of batteries elements by CDs, CDs composites, and CDs derivatives. Moreover, it systematically encapsulates the application of CDs in zinc‐based batteries, underscoring the pivotal role of CDs in the advancement of electrode technology. Finally, the review highlights the impediments and proposes potential avenues for utilizing CDs in zinc‐based batteries. This review aims to facilitate the development of superior solutions and provide scientific insights into energy storage technologies. [ABSTRACT FROM AUTHOR]

[Display omitted] • CDs and CMs with good biocompatibility were prepared. • CMB and CMC stimulated the maturation of DC cells and activated T cells. • CMB and CMC can target LNs and induce an immune response to treat primary and distal tumor models. • CMB and CMC can specifically target B16F10 and CT26 tumors, respectively. Although therapeutic nanovaccines have made a mark in cancer immunotherapy, the shortcomings such as poor homing ability of lymph nodes (LNs), low antigen presentation efficiency and low antitumor efficacy have hindered their clinical transformation. Accordingly, we prepared advanced nanovaccines (CMB and CMC) by integrating carbon dots (CDs) with tumor-associated antigens (B16F10 and CT26). These nanovaccines could forwardly target tumors harbouring LNs, induce strong immunogenicity for activating cytotoxic T cells (CTLs), thereby readily eliminating tumor cells and suppressing primary/distal tumor growth. This work provides a promising therapeutic vaccination strategy to enhance cancer immunotherapy. [ABSTRACT FROM AUTHOR]

The development of an eco-friendly, cost-effective and highly efficient bio-based catalyst is of great significance in organic transformations. Traditionally and currently used catalysts and solvents persist some limitations including high cost, toxicity, less stability, or eco-destructive. Herein, we report an eco-friendly green approach for synthesizing arylidene propanedinitrile (malononitrile) by using carbon dots as a novel precursor derived from waste peels of Citrus limetta. A series of arylidene propanedinitrile compounds were synthesized and subjected to in vitro antioxidant and antimicrobial activity. The compounds displayed a potent effect against clinical isolates of Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive). Furthermore, the antioxidant assays for these arylidene propanedinitrile derivatives were performed where 3b, 3c, 3e and 3i yielded the most promising results against DPPH and compound 3a, 3f, 3 h and 3j gave best results against ABTS free radical. These preliminary bioassay results clearly represent that these compounds have great potential in medical science. [ABSTRACT FROM AUTHOR]

Carbon nanomaterials (CNMs), comprising carbon dots, graphene‐related materials, and carbon nanotubes, have significant potential for enhancing agricultural productivity. Their compositional compatibility and exceptional properties intrigue a great deal of explorations in agricultural applications, such as fertilizers, pesticides, and regulators of plant growth. However, the evaluation of their agricultural applicability often lacks quantitative sustainability metrics, with insufficient scrutiny on the carbon footprint and scalability of the manufacturing. This review attempts to provide a quantitative ranking system for evaluating the manufacturing processes of the CNMs by applying the twelve principles of Green Chemistry, particularly in the context of agriculture applications. The review also offers a systematically organized account of CNMs' effects on plant systems, encompassing nutrient enhancement, photosynthesis, soil amelioration, disease resistance, and phytotoxicity, which can provide design rationales for the further development of CNMs. [ABSTRACT FROM AUTHOR]

Synthesis of functional nanostructures with the least number of tests is paramount towards the propelling materials development. However, the synthesis method containing multivariable leads to high uncertainty, exhaustive attempts, and exorbitant manpower costs. Machine learning (ML) burgeons and provokes an interest in rationally designing and synthesizing materials. Here, we collect the dataset of nano-functional materials carbon dots (CDs) on synthetic parameters and optical properties. ML is applied to assist the synthesis process to enhance photoluminescence quantum yield (QY) by building the methodology named active adaptive method (AAM), including the model selection, max points screen, and experimental verification. An interactive iteration strategy is the first time considered in AAM with the constant acquisition of the furnished data by itself to perfect the model. CDs exhibit a strong red emission with QY up to 23.3% and enhancement of around 200% compared with the pristine value obtained through the AAM guidance. Furthermore, the guided CDs are applied as metal ions probes for Co2+ and Fe3+, with a concentration range of 0–120 and 0–150 µM, and their detection limits are 1.17 and 0.06 µM. Moreover, we also apply CDs for dental diagnosis and treatment using excellent optical ability. It can effectively detect early caries and treat mineralization combined with gel. The study shows that the error of experiment verification gradually decreases and QY improves double with the effective feedback loops by AAM, suggesting the great potential of utilizing ML to guide the synthesis of novel materials. Finally, the code is open-source and provided to be referenced for further investigation on the novel inorganic material prediction. [ABSTRACT FROM AUTHOR]

The rapid quantification of hydroxyl radical (·OH) in real samples is a great challenge due to its highly reactive nature and the potential interferences from other coexisting reactive oxygen species (ROS). Herein, a chemiluminescence (CL) probe (ox-CDs) was rationally developed for the detection of ·OH through controlled oxidation treatment of original CDs (o-CDs) with H2O2. Post-oxidation of CDs can reduce the surface defects or functional groups on the CDs, exposing reactive sites capable of effectively reacting with ·OH. The chemical energy generated from redox reaction between ·OH and the ox-CDs can be efficiently utilized to generate strong and selective CL responses to ·OH without interferences from other ROS. Thus, a highly selective and sensitive CL method with a linear range from 0.01 to 150 μM and a detection limit of 3 nM was developed, which was successfully applied for monitoring the ·OH production from cigarette and mosquito coil smoke. [ABSTRACT FROM AUTHOR]

The unique properties that aerogels exhibit have been the main reason for the intense research around new synthesis routes and new applications in various fields in recent years. Composite aerogels combine the properties of both the aerogel matrix and the inclusions, where the latter can be several materials in various forms. Carbon dots are suitable candidates to use as inclusion for the development of composite aerogels and that is due to their low-cost production, low toxicity, biocompatibility, and tunable fluorescence. Here we report the synthesis of a composite silica matrix aerogel with boron-doped carbon dots inclusions, and we focus on the optical response of the material. The method we use to prepare the composite aerogel is the classical sol-gel process using tetraethyl orthosilicate as silica precursor, followed by CO2 supercritical drying. The resulting aerogel is crack-free, exhibiting a surface area of 518 m2/g and diverse optoelectronic properties compared to the pristine carbon dots in solution, as an excitation-dependent emission and an unusual blue-shift for excitation centered in the UVB region. The unfamiliar optoelectronic properties of the carbon dots in the aerogel are discussed and are attributed to the influence of the silica matrix. Hence, the induced carbon dots' aggregation may lead to recombination de-excitation pathways, whereas the photoluminescence contribution by the core-related de-excitation pathway may shorten, as the penetration depth of radiation into the dots' core may be affected by its intensity which drops drastically for high energies (for λexc. < 300 nm) due to strong absorption by the silica matrix. Highlights: Crack-free composite silica aerogels with photoluminescent carbon dots inclusions. Composite aerogels preserve their porous character with specific surface areas above 500 m2/g. Diverse optoelectronic properties compared to the pristine carbon dots in solution. Excitation-dependent emission and unusual blue-shift for excitation centered in the UVB region. The observations are attributed to several factors linked to the silica matrix. [ABSTRACT FROM AUTHOR]

Consumers and food industry stakeholders have expressed great interest in using simple, non‐destructive and inexpensive methods to control/maintain or monitor the freshness of perishable foods. The idea of smart packaging has been introduced to address these requirements satisfactorily, revolutionizing conventional food packaging. Vaccinium corymbosum (VC)–based carbon dots (CDs) and anthocyanin were matrixed on gelatin (GEL) to fabricate smart packaging film. The VC biowaste–derived carbon dots (VC‐CDs) were characterized using photoluminescence, fluorescence spectrometry, FTIR, antibacterial/antioxidant potential, TEM and XPS analysis. Fabricated films were subjected to physico‐chemical, antioxidant and optical properties, SEM, TGA simulation and in vivo food model system. The VC‐CDs exhibited excellent functional properties like ultraviolet (UV) blocking and antibacterial properties. The reinforcement with 1.5% VC‐CDs and 6% VC anthocyanins (VCA) in the GEL polymer matrix improved UV blocking (> 189%) properties and showed potent antioxidant potential (> 164%) compared to the neat GEL film. In vivo food packaging (minced pork, fish and shrimp) with films has shown that indicator films work efficiently and non‐destructively and monitor real‐time freshness. The GEL/VC‐CDs/VCA‐based active and intelligent films are expected to be applied as multifunctional nanocomposite packaging materials that can indicate quality changes in real time, maintain quality and prolong the shelf life of packaged foods. [ABSTRACT FROM AUTHOR]

we successfully developed a new class of nitrogen-doped carbon dots (N-CDs) using a unique combination of hyaluronic acid (HA), citric acid (CA), and urea. This synthesis, achieved through an efficient one-pot hydrothermal process, has ushered in a new era for bio-imaging and forensic science applications. The N-CDs, characterized techniques such as Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), and Photoluminescence Spectroscopy (PL), demonstrated outstanding fluorescence properties. These properties were maintained under various pH levels and even under prolonged UV exposure, showcasing their remarkable stability. The transformative potential of these N-CDs was further evidenced in their biocompatibility and efficacy in bio-imaging. When tested in vitro with human cell lines, the N-CDs not only exhibited efficient cellular uptake but also ensured minimal cytotoxicity, marking a significant advancement in safe and effective bio-imaging techniques. Moreover, in the realm of forensic science, the N-CDs proved to be a game-changer for latent fingerprint analysis. Their application on glass surfaces revealed minute fingerprint details, such as ridges and sweat pores, with unprecedented clarity. This exceptional performance is attributed to their luminous properties and their interaction with amino acids and proteins present in fingerprint residues. Our findings pave the way for these N-CDs, synthesized from HA, CA, and urea, to be recognized as versatile and powerful tools. They hold immense promise not only in advancing bio-imaging methodologies but also in revolutionizing forensic techniques for latent fingerprint detection across various surfaces. This study, therefore, presents a significant leap forward in both biomedical and forensic science fields, demonstrating the far-reaching applications of these innovative nanocomposites. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs), known for their quantum size, abundant surface functional groups, excellent biocompatibility, and non‐toxicity, have emerged as promising candidates for enhancing various advanced rechargeable batteries. Recent research indicates that electrodes based on or modified with CDs in sodium‐ion batteries (SIBs) have shown significant improvements in key performance metrics such as Coulombic efficiency, cycle life, and capacity compared to traditional electrodes. Several key impacts of CDs contribute to these enhancements, including increased conductivity due to their conductive graphitized core, rich absorption sites, and excellent dispersity facilitated by abundant surface functional groups. These features accelerate ion transport through interface edges and ion diffusion paths, inhibit electrode material dissolution, buffer electrode material volume expansion, ensure electrode uniformity and stability, and promote the electrochemical reaction process between the electrode and electrolyte. This review summarizes recent developments, challenges, and opportunities in leveraging CDs as additives in SIBs, focusing on their impact on electrolyte properties, electrode materials, and overall battery performance. It provides a comprehensive understanding of the potential of CDs to significantly advance SIB technology. [ABSTRACT FROM AUTHOR]

AbstractCarbon nanomaterials have been widely applied for cutting edge therapeutic applications as they offer tunable physio-chemical properties with economic scale-up options. Nuclear delivery of cancer drugs has been of prime focus since it controls important cellular signaling functions leading to greater anti-cancer drug efficacies. Better cellular drug uptake per unit drug injection drastically reduces severe side-effects of cancer therapies. Similarly, carbon dots (CDs) uptaken by the nucleus can also be used to set-up cutting edge nano delivery systems. In an earlier paper, we showed the cellular uptake and plasma membrane impact of combustion generated yellow luminescing CDs produced by our group from fuel rich combustion reactors in a one-step tunable production. In this paper, we aim to specifically study the nucleus by establishing the uptake kinetics of these combustion-generated yellow luminescing CDs. At sub-lethal doses, after crossing the plasma membrane, they impact the actin and microtubule mesh, affecting cell adhesion and migration; enter nucleus by diffusion processes; modify the overall appearance of the nucleus in terms of morphology; and alter chromatin condensation. We thus establish how this one-step produced, cost and bulk production friendly carbon dots from fuel rich combustion flames can be innovatively repurposed as potential nano delivery agents in cancer cells. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) are ideal fluorophores for optoelectronic devices. However, it is still a great challenge to obtain CDs with high solid‐state photoluminescence quantum yields (PLQYs). In this work, it is first reported that the barium‐doped CDs (Ba‐CDs), which can be simply synthesized on a large scale via a direct one‐step heating approach using an open vessel. The as‐synthesized Ba‐CDs exhibit ultrabright luminescence both in liquid and solid states. The as‐synthesized Ba‐CDs with a scale of 8.6 g per batch show a Stokes shift of ≈0.68 eV and high PLQYs of 80.8% and 66.8% in liquid and solid state, respectively. Interestingly, an efficient fluorescence enhancement phenomenon occurs when Ba‐CDs are mixed with polyvinylpyrrolidone (PVP), which reveals the critical issue of compatibility between CDs and polymer matrix can be well resolved. As a proof‐of‐concept, the Ba‐CDs are employed as fluorophores for high‐efficiency luminescent solar concentrator (LSC) fabrication. The Ba‐CDs@PVP‐based LSC has a PLQY of 88.78%, showing a breakthrough optical conversion efficiency of 7.16% and power conversion efficiency of 6.87% under natural light irradiation (40 mW cm−2). The results demonstrate the potential application of the ultrabright Ba‐CDs in efficient photovoltaic devices. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) have emerged as an exceptional material for the emission layer in the new generation of electroluminescent light‐emitting diodes (ELEDs) owing to their low cost, high stability, and high luminous efficiency. Although blue CDs‐based ELEDs have a wide bandgap and a low exciton utilization efficiency (EUE), it is still challenging to increase their external quantum efficiency (EQE). Although thermally activated delayed fluorescence and triplet‐triplet annihilation may improve EUE, the design of blue ELEDs is complicated by the significant charge transfer characteristics introduced by the low energy spitting of T1 and S1. This research effectively produced blue‐emitting CDs using a heated exciton process by carefully selecting precursors to overcome the aforementioned challenges. Deep blue and blue ELEDs based on CDs are developed by manipulating the electron‐hole mobility and the energy level structure of the device. The EQEs of these ELEDs exceeded those of previously reported CDs‐based blue ELEDs by over 7%. This study presents design concepts for new CDs and introduces a novel approach to develop cost‐effective, environmentally friendly, and highly efficient metal‐free blue ELEDs. [ABSTRACT FROM AUTHOR]

The two‐electron oxygen reduction reaction (2e− ORR) is a pivotal pathway for the distributed production of hydrogen peroxide (H2O2). In nature, enzymes containing manganese (Mn) centers can convert reactive oxygen species into H2O2. However, Mn‐based heterogeneous catalysts for 2e− ORR are scarcely reported. Herein, we developed a nature‐inspired single‐atom electrocatalyst comprising N, O co‐coordinated Mn sites, utilizing carbon dots as the modulation platform (Mn CD/C). As‐synthesized Mn CD/C exhibited exceptional 2e− ORR activity with an onset potential of 0.786 V and a maximum H2O2 selectivity of 95.8 %. Impressively, Mn CD/C continuously produced 0.1 M H2O2 solution at 200 mA/cm2 for 50 h in the flow cell, with negligible loss in activity and H2O2 faradaic efficiency, demonstrating practical application potential. The enhanced activity was attributed to the incorporation of Mn atomic sites into the carbon dots. Theoretical calculations revealed that the N, O co‐coordinated structure, combined with abundant oxygen‐containing functional groups on the carbon dots, optimized the binding strength of intermediate *OOH at the Mn sites to the apex of the catalytic activity volcano. This work illustrates that carbon dots can serve as a versatile platform for modulating the microenvironment of single‐atom catalysts and for the rational design of nature‐inspired catalysts. [ABSTRACT FROM AUTHOR]

The inefficient delivery of herbicides causes unpleasant side effects on the ecological environment. Protoporphyrinogen oxidase (PPO)‐inhibiting herbicides rely on the presence of external light to exert the activities and thus their performance in the field is extremely susceptible to the light environment. Here, taking acifluorfen (ACI) as a model PPO‐inhibiting herbicide to enhance efficacy by boosting the utilization rate of sunlight, amphiphilic cationic CDs (CPC‐CDs) from cetylpyridinium chloride (CPC) as a precursor, is first prepared as a supplementary light source generator, and subsequently co‐assembled with ACI through non‐covalent bond interactions to obtain the stable fluorescent nanoparticles (ACI@CPC‐CDs). ACI@CPC‐CDs with fascinating physicochemical properties can penetrate the leaves of weeds through the stomata and undergo a long‐distance transport in the cell intervals. Under low light intensity, CPC‐CDs can be applied as the internal light source to promote the formation of more singlet oxygen to damage the leaf cell membrane, consequently improving the herbicidal activity of ACI. Moreover, the safety evaluation of ACI@CPC‐CDs demonstrates no risk to non‐target organisms and the environment. Therefore, this work offers a promising strategy for the efficient delivery of light‐dependent PPO‐inhibiting herbicides and opens new insights into the application of CDs in the development of sustainable agriculture. [ABSTRACT FROM AUTHOR]

Chemotherapy for hepatoblastoma is limited by organ toxicity and poor outcomes, prompting the search for new, more effective treatments with minimal side effects. Vincristine sulfate, a potent chemotherapeutic, faces challenges due to P-glycoprotein-mediated resistance and its systemic toxicity. Nanoparticles offer a promising solution by improving pharmacokinetics, targeting tumor cells, thus reducing side effects. Moreover, the use of fluorescent nanomaterials is emerging in biomedical applications such as bioimaging, detection and therapies. This study describes a promising delivery system utilizing carbon dots encapsulated with vincristine in biodegradable polycaprolactone nanoparticles via a double emulsion technique. The fine characterization of these nanoparticles showed that they are spherical, uniformly sized with around 200 nm and exhibit excellent colloidal stability. Moreover, the release profile showed prolonged release for both vincristine and carbon dots. In vitro cell viability studies revealed enhanced cancer cell inhibition for the encapsulated drug compared to the vincristine solution. The uptake study indicated clear fluorescence for carbon dots solution and vincristine and carbon dots loaded nanoparticles upon excitation. Additionally, studies on primary mouse hepatocytes demonstrated higher fluorescence intensity in treatment groups. These results suggest that vincristine and carbon dots loaded nanoparticles are effective, target-specific carriers for liver cancer treatment. Furthermore, the carbon dots were not cytotoxic, highlighting their potential in bioimaging and cancer cell studies. [ABSTRACT FROM AUTHOR]

High‐capacity steganography is crucial for the secure exchange of massive information. Exploring orthogonally optical recording can significantly improve encryption levels. However, due to the lack of robust media, the hidden data are easy to be cracked or destructed. Herein, carbon dots have the switchable memory function between optical transmittance and polarization state after receiving excitation power adjustment is discovered. A large‐area carbon‐based disk is further constructed which is measured to resist the high‐temperature damage at 423 K for more than 405 h and is estimated to remain stable at room‐temperature (301 K) beyond 2341 years. With the alternated arrangement of the dual functional carbon dots at one region of the disk, only by using an amplitude‐type holographic diffraction key can the polarized pattern be correctly read out. The ultra‐high secure encryption strategy also puts a bright way to the applications of 3D image hiding, permanent data preservation, and anti‐counterfeiting labels. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) are a type of carbon-based nanomaterial that has gained a lot of attention in the field of electrochemical catalysis. They have unique physical and chemical properties, such as high specific surface area, defects, heteroatom doping ability, and functional groups on their surface. These properties make them particularly effective in electrocatalysis, including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and carbon dioxide reduction (CO 2 RR). This review summarizes various methods for the preparation of CDs, including top-down methods and bottom-up methods, and analyzes their structure and properties in detail. It also delves into the role of CDs and their composites in specific electrocatalytic reactions, as well as the technical challenges they face in practical applications. Looking forward to the future, with the continuous progress of material science, nanotechnology and electrochemical theory, the potential applications of CDs and their composites in electrocatalysis are expected to be further expanded. • The preparation methods, structures and properties of CDs are introduced. • CDs are summarized as electrocatalysts for HER, OER, ORR and CO 2 RR. • The challenges of CDs in the field of electrocatalysis are summarized. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) derived from mandarin peel biochar (MBC) at different pyrolysis temperatures (200, 400, 600, and 800 °C) have been synthesized and characterized. This high-value transformation of waste materials into fluorescent nanoprobes for environmental monitoring represents a step forward towards a circular economy. In this itinerary, CDs produced via one-pot hydrothermal synthesis were utilized for the detection of copper (II) ions. The study looked at the spectroscopic features of biochar-derived CDs. The selectivity of CDs obtained from biochar following carbonization at 400 °C (MBC400-CDs towards various heavy metal ions resulted in considerable fluorescence quenching with copper (II) ions, showcasing their potential as selective detectors. Transmission electron microscopic (TEM) analysis validated the MBC-CDs' consistent spherical shape, with a particle size of <3 nm. The Plackett–Burman Design (PBD) was used to study three elements that influence the F0/F ratio, with the best ratio obtained with a pH of 10, for 10 min, and an aqueous reaction medium. Cu (II) was detected over a dynamic range of 4.9–197.5 μM and limit of detection (LOD) of 0.01 μM. Validation testing proved the accuracy and precision for evaluating tap and mountain waters with great selectivity and no interference from coexisting metal ions. [ABSTRACT FROM AUTHOR]

This study evaluates silver-doped carbon dots (AgCDs) as a novel agent for chemical castration using a rat model. Six groups of rats (five males and ten females each, except for the surgical group which had only males) were utilized to compare the effects of different concentrations of AgCDs. The groups included control, sham, and three experimental groups injected with 1.25, 50, and 200 µg/mL AgCDs, respectively, along with a surgical castration group. Testosterone levels, sperm parameters, fertility index, oxidative damage, histopathological parameters, and gene expression of P53, Bax, Bcl-2, caspase-3, AKT, and PI3K were analyzed. Results demonstrated that the high-dose AgCDs group significantly reduced testosterone levels, sperm concentration, and motility, resulting in a decreased fertility index. MDA and NO significantly increased, while CAT, SOD, GPx, and TAC significantly reduced in the chemically castrated groups. Histological and genes expression analysis also revealed apoptosis and testicular damage in the AgCDs groups, indicated by significant increases in P53, Bax, and Caspase-3 levels, and significant reductions in AKT, PI3K, and Bcl-2. Based on these findings, AgCDs could be considered a potent and efficient agent for chemical castration, offering a less invasive, cost-effective solution with potential applications for population control. [ABSTRACT FROM AUTHOR]

[Display omitted] Carbon dots (CDs), a type of nanoparticle with excellent optical properties, good biocompatibility, and small size, are finding increasing application across the fields of biology and biomedicine. In recent years, biomass-derived CDs with pharmacological activity (BP-CDs) derived from herbal medicines (HMs), HMs extracts and other natural products with demonstrated pharmaceutical activity have attracted particular attention. Herein, we review recent advances in the development of BP-CDs, covering the selection of biomass precursors, different methods used for the synthesis of BP-CDs from natural sources, and the purification of BP-CDs. Additionally, we summarize the many remarkable properties of BP-CDs including optical properties, biocompatibility and pharmaceutical efficacy. Moreover, the antibacterial, antiviral, anticancer, biosensing, bioimaging, and other applications of BP-CDs are reviewed. Thereafter, we discuss the advantages and disadvantages of BP-CDs and Western drug-derived CDs, highlighting the excellent performance of BP-CDs. Finally, based on the current state of research on BP-CDs, we suggest several aspects of BP-CDs that urgently need to be addressed and identify directions that should be pursued in the future. This comprehensive review on BP-CDs is expected to guide the precise design, preparation, and future development of BP-CDs, thereby advancing the application of BP-CDs in biomedicine. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) possess intrinsically broad emission spectra, making them suitable for modulating high‐quality white light‐emitting diodes (WLEDs). However, the chief technical challenge in applying CDs to WLEDs is the aggregation‐caused quenching (ACQ) effect. A common solution is polymer post‐modification on the surface of CDs, which is a low‐yield, hard‐to‐purified, and complicated process. Herein, polymerized CDs with broad emission (full width at half maxima, FWHM = 187 nm) are synthesized via a one‐step solvothermal method. The obtained polymerized CDs display excellent solution‐processed and film‐forming capabilities, with absolute photoluminescence quantum yield as high as 4.7% in thin film state, creating a firm foundation for assembling solution‐processed WLEDs. Moreover, the polymerization steps of CDs are analyzed and described in detail. The polymer chains prevent ACQ and create new energy levels, resulting in the broad emission of CDs in an aggregated state. Subsequently, WLEDs are fabricated using polymerized CDs as the single active emitting material. The optimal device achieves the maximum brightness of 337.50 cd m−2 and FWHM of 242 nm, covering nearly the entire visible spectral window. The results present a new approach to obtaining polymerized CDs and further fabricating WLED with a straightforward, cost‐effective method. [ABSTRACT FROM AUTHOR]

The impact of food contaminants on ecosystems and human health has attracted widespread global attention, and there is an urgent need to develop reliable food safety detection methods. Recently, carbon dots (CDs) have been considered as a powerful material to construct sensors for chemical analysis. Based on the concept of resource conversion and sustainable development, the use of natural, harmless, and renewable materials for the preparation of CDs without the involvement of chemical hazards is a current hot topic. This paper reviews the research progress of green-derived CDs and their application in food safety biosensing. The fabrications of green-derived CDs using various biomasses are described in detail, and the application of CDs especially the sensing mechanisms of photoluminescence, colorimetric, electrochemiluminescence and other sensors are provided. Finally, existing shortcomings and current challenges as well as prospects for food safety monitoring are discussed. We believe that this work provides strong insight into the application of CDs in the sensing of various contaminants. [ABSTRACT FROM AUTHOR]

This study proposed a novel electrochemical sensor for the sensitive measurement of the eye medication ofloxacin (OFX), which is based on a NiO@C-dot nanocomposite. The NiO@C-dot nanocomposite was synthesized using the sol-gel method, which was then applied to alter a glassy carbon electrode (GCE). With regard to OFX, the modified GCE shown outstanding electrochemical activity along with good sensitivity, selectivity, and stability. With OFX concentrations ranging from 5 µM to 975 µM, the NiO@C-dot/GCE showed a linear relationship with a sensitivity of 0.63994 µA/µM. The limit of detection (LOD) was 0.023 µM. The response to 50 µM OFX was measured, and the electrode was stored at 4°C after each test in order to evaluate the sensor's long-term stability and repeatability. After 20 days, the peak current response was still 97.89 % of its initial value. After 40 days of prolonged storage, 93.78 % of the electrode's original responsiveness was retained. The sensor showed a recovery rate of 97.37–99.70 % in all sample types when it was used to detect OFX in human urine, tap water, and food samples. These findings highlight the NiO@C-dot/GCE's outstanding selectivity, dependability, and longevity as solid platforms for OFX detection in complicated samples for a range of applications. [ABSTRACT FROM AUTHOR]

Cancer represents a prominent health concern on a global scale and stands as a significant contributor to mortality. The accurate quantification of anti-cancer drugs such as paclitaxel in human biofluids is critical for effective treatment and monitoring. In this study, a straightforward one-step hydrothermal method was presented for synthesizing carbon dots (CDs), eliminating the need for any additional decoration or modification, by utilizing combretum micranthum extract as a natural carbon source. A paclitaxel sensor was fabricated by modifying a glassy carbon electrode (GCE) with the green synthesized CDs. At optimal conditions, the CDs-GCE exhibited a linear response for paclitaxel analysis in a range of 0.07 µM to 35 µM, with a low detection limit of 2.1 nM. The suggested sensor indicates acceptable reproducibility for paclitaxel detection ((RSD=2.6 %). In addition, the CDs-GCE depicts a good resistant versus common interfering species including flutamide, dopamine, glucose, nilutamide, lactose, tinidazole, ascorbic acid, and L -cysteine. The applicability of the sensor for paclitaxel detection in human serum and human urine samples was effectively assessed. The presented electrochemical sensing protocol for paclitaxel detection offers several merits, including a low limit of detection, fast response time, resistance to interference, and ease of use. [Display omitted] • A novel green strategy was employed for preparation of high stability of carbon dots (CDs). • The sensor exhibited a linear response for paclitaxel over a wide concentration range (0.07 µM to 35 µM). • The applicability of the sensor for paclitaxel detection in human biofluids was successfully assessed. [ABSTRACT FROM AUTHOR]

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Carbon dots (CDs), a new member of the nanocarbon family, are revolutionizing a wide range of fields. This new member has been the subject of extensive international research. Its synthesis methods, characteristics, and applications are active research areas. Carbon dots are nanoparticles composed of carbon with a diameter of less than 10 nm. The distinctive structure and size of CDs suggest that their physical, chemical, electrical, and optical properties are modifiable. In addition, they possess properties such as low toxicity, high water solubility, chemical stability, photoluminescence, photostability, electroluminescence, high quantum yield, high surface area, heteroatom doping capability, abundance of surface functional groups, good conductivity, and environmental friendliness. This review attempts to provide an introductory story of carbon dots. From the early beginning of CDs through the myriad of synthesis techniques used to date, the review advances to the properties and applications that have not yet been fully explored. The principal applications covered include fluorescence detection, electrochemical sensing, pH monitoring, fluorescent ink, and metal nanoparticle synthesis. Recent developments, gaps, and obstacles for each of these applications have been discussed. [ABSTRACT FROM AUTHOR]

New nitrogen‐doped carbon quantum dots (NCQDs) made from Dioscorea alata (DA) extract as the carbon and nitrogen source using the hydrothermal method provide a straightforward approach for extremely sensitive and selective quantification of Cu (II) ions. In this method, aqueous extract of DA served as the carbon source and aqueous ammonia was used as the nitrogen dopant. To characterize NCQDs, a variety of analytical approaches have been utilized. The average size of NCQDs was analyzed using Transmission electron microscopy (TEM) and it was found to be 6.54 nm. Using X‐ray diffraction pattern and Raman spectroscopy, the graphitic nature of the green synthesized NCQDs was investigated. Strong green fluorescence was generated under 365 nm excitation of NCQDs, with an emission wavelength of around 460 nm. Fourier transform infrared analysis confirms the presence of various functional groups in the synthesized NCQDs. The NCQDs have the potential to serve as an extremely sensitive and selective fluorescent probe for Cu (II) ion detection, with a correlation coefficient (R2) of −0.9927 and a limit of detection of 4.2 nm. The NCQDs were then employed as probes to detect Cu (II) ions in river water and tap water. [ABSTRACT FROM AUTHOR]

Carbon Dots (CDs) were synthesized from peanut shells (PNS) through pyrolysis and characterized using FTIR, XRD, HRTEM and BET analysis revealing an average size of 2–5 nm with amorphous nature. Synthesized PNS-CDs was employed both as priming and foliar agent for enhancing seed quality and crop productivity in blackgram (Vigna mungo L. Hepper). Different concentrations ranging from 50, 100, 200, 300, 400, 500 and 1000 ppm was used for seed priming and 5, 10, 15, 20, 25, 50, 75 and 100 ppm were given as foliar spray on 30th and 45th days after sowing (DAS). On accounting the best seed priming and foliar spray concentrations, field trial was conducted to validate the optimistic effect of PNS-CDs on blackgram crop productivity. Results revealed that priming with 200 ppm for 3 h exhibited maximum seed imbibition (54%), germination (88%) and vigour index (3165). Whereas, foliar spray with 50 ppm expressed significant improvement in leaf area index (2.6), total chlorophyll (2.70 mg/g), total soluble protein (71 mg/g), Number of nodules/plant (138), seed yield/plant (8.7 g) and 100 seed weight (5 g). The impact of PNS-CDs treatments resulted in increased photosynthetic rate (12.45 µmol CO2 m−2s−1), transpiration rate (3.13 mmol H2O/m−2s−1), stomatal conductance (0.55 mol H2O/m−2s−1) and internal leaf CO2 concentration (652 µmol CO2 m−2s−1) which ultimately enhanced the photosynthetic efficiency of plants. It has also exhibited a promising effect on the resultant seed in which the combination seed priming (200 ppm) followed by foliar spray (50 ppm) recorded maximum 100 seed weight (4.19 g), germination (97%) and vigour index (3019). Thus, this study highlights the promising role of PNS-CDs as a sustainable and effective agricultural nanomaterial, offering a novel approach to utilize the agricultural waste and also to enhance the crop productivity through advanced non-chemical approach. [ABSTRACT FROM AUTHOR]

Sodium metal batteries with high theoretical energy density and low redox potential possess vast application prospects. However, the inevitable side reactions between Na metal anode and electrolyte, the formation of Na dendrite during cycling, and the uneven electric field distribution at the interface will lead to a decrease in the cycling stability of the battery. Herein, N and S co‐doped carbon dots are employed as electrolyte additives in view of their quantum size, excellent dispersion, and polar surface functional groups. It is found that the quantum‐sized carbon core and sodiophilic surface functional groups of N,S‐CDs enable the homogenous deposition of Na+ and the involvement of N,S‐CDs in the formation of solid electrolyte film. The N,S‐CDs co‐deposition guarantees the uniform sodium plating in the initial cycle, avoiding the routine dendrite growth. The strength and stability of SEI are boosted with the assistance of inorganics such as Na3N and Na2S, which accelerate the transport of Na+ flux and realize rapid charge transfer at the interface, ensuring high reversibility of sodium ion plating/stripping. Na||Cu half‐cells achieve a coulombic efficiency of 99% after 250 cycles under 1.0 mA cm−1, and Na||Na symmetric cells continuously cycle over 1200 h at a current density of 1 mA cm−2. [ABSTRACT FROM AUTHOR]

Room temperature phosphorescence (RTP) provides a longer and tunable afterglow time compared to conventional fluorescence, enabling complex information encryption effects. However, traditional RTP materials have a short afterglow, and acquiring the requisite raw materials is challenging. In this study, RTP carbon dots (CDs) were synthesized using a multifaceted method, achieving an extended lifetime of 743.55 ms. The afterglow duration of 23.5 s under 254 nm excitation. Additionally, the afterglow intensity was enhanced through Na doping. Notably, the B2O3 matrix confine the vibration and rotation of the CDs chromophores. Mechanisms such as hydrogen bonding and covalent bonding collectively mitigate nonradiative decay of the triplet exciton. Furthermore, the potential application of these materials in information encryption is demonstrated. This investigation serves as a valuable reference for enhancing the afterglow properties and applications of RTP-CDs. [ABSTRACT FROM AUTHOR]

The practical application of solid polymer electrolyte is hindered by the small transference number of Li+, low ionic conductivity and poor interfacial stability, which are seriously determined by the microenvironment in polymer electrolyte. The introduction of functional fillers is an effective solution to these problems. In this work, based on density functional theory (DFT) calculations, it is demonstrated that the anion vacancy of filler can anchor anions of lithium salt, thereby significantly increasing the transference number of Li+ in the electrolyte. Therefore, flower‐like SnS2‐based filler with abundant sulfur vacancies is prepared under the regulation of functionalized carbon dots (CDs). It is worth mentioning that the CDs dotted on the surface of SnS2 have rich organic functional groups, which can serve as the bridging agent to enhance the compatibility of filler and polymer, leading to superior mechanical performance and fast ion transport pathway. Additionally, the in situ formed Li2S/Li3N at the interface of Li metal and electrolyte facilitate the fast Li+ diffusion and uniform Li deposition, effectively mitigating the growth of lithium dendrites. As a result, the assembled lithium metal batteries exhibit excellent cycling stability, reflecting the superiority of the carbon dots derived vacancy‐rich inorganic filler modification strategy. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) have garnered significant attention owing to their fluorescence properties and biocompatibility, especially red fluorescent CDs for bio-imaging and optoelectronics. However, existing red fluorescent carbon dots exhibit limitations regarding shorter red wavelengths, lower fluorescence intensities, and complex preparation procedures. This paper employed the microwave method to synthesize four water-soluble red fluorescent carbon dots, utilizing p-phenylenediamine and urea as precursors. By doping with manganese and adjusting the precursor concentration, we enhanced the intensity and the wavelength of red fluorescence under 365 nm UV light. The manganese-decorated carbon dots (Mn-CDs) showed a 32 nm redshift compared to the original carbon dots (O-CDs). The manganese-decorated/precursor concentration changed carbon dots (Mn/P-CDs) had four times higher intensity and 677 nm wavelength. The enhancement was mainly due to the increased nitrogen content from manganese addition and the decreased precursor concentration. We also synthesized composite polyfluorescent films with four CDs as pigments, exhibiting excellent transparency, flexibility, and luminescence in various media. Importantly, we demonstrated that their luminescent properties remained intact across multiple media. This study provides a valuable method for high-quality red CDs synthesis and a novel perspective for their applications. [ABSTRACT FROM AUTHOR]

The detection of pH and water is critical in the life sciences and chemical industries. The yellow fluorescent carbon dots (CDs) synthesized by solvothermal method using neutral red (NR) as carbon source, ethylenediamine (EDA) as nitrogen source and ethanol as solvent was studied. It was found that the carbon dots (NR-EDA-CDs) could produce double emission peaks when the excitation wavelength was in the range of 310~370 nm. Therefore, a method for the detection of pH and water with a double ratio fluorescence probe based on a single luminant was established. The carbon dots were characterized by high-resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy, infrared spectroscopy and X-ray photoelectron spectroscopy. The results showed that the carbon dots are spheroidal in shape, with an average particle size of 3. 6 nm and obvious graphite structure. It was found that the carbon dots has good stability, photobleaching resistance and salt tolerance at the excitation wavelength of 365 nm. In phosphate buffer solution, pH in the range of 4. 15~8. 55 has a good linear relationship with the fluorescence intensity ratio of 581 and 449 nm (F581/ F449), and its coefficient (R²) is 0. 986. The pH ratio fluorescent probe has the characteristics of wide linear range and good reversibility. At the same time, it was found that the content of water in DMSO is linear with F485/ F585 in the range of 0. 6%~50% (V (H2O) / V (DMSO)), R² is 0. 996, and the detection limit is 0. 18% (V (H2O)/ V (DMSO)) . The double ratio fluorescent probe provides a new method for the detection of pH and water. [ABSTRACT FROM AUTHOR]

In order to solve the problem of reduced fluorescence intensity caused by aggregation of carbon dots (CDs) in solution, this study successfully optimized the synthesis conditions for amination-modified carbon dots (N-CDs) by adjusting factors such as nitrogen source, reaction temperature, and time, making the fluorescence stable and easy combination with natural polymers. Additionally, the semi-dissolution acidification sol–gel transition (SD-A-SGT) method was used to prepare the carboxymethylcellulose (CMC) and chitosan (CS) composite hydrogels, achieving a high content of CDs with a straightforward process. Fluorescence properties, chemical composition, and morphological characteristics of CD fluorescent hydrogels were analyzed. The results showed that the fluorescent hydrogels revealed distinct absorption bands in the FT-IR spectra (1601 cm−1, 1395 cm−1, and 1632 cm−1), indicating the formation of intermolecular complexes. CS and CMC in N-CDs/CMC/CS composite hydrogels formed intermolecular complexes through strong electrostatic and hydrogen-bonding interactions between NH3+ and COO− groups, exhibiting an interconnected porous network structure that provided space for the uniform dispersion of N-CDs. Compared to the aqueous N-CDs solution, the fluorescence curve of the N-CDs/CMC composite was slightly enhanced (1.82%) and broadened, and N-CDs achieved ideal immobilization at high content in the gel system without quenching. This work develops an environmentally friendly composite hydrogel with strong fluorescence, holding promising applications in metal detection. [ABSTRACT FROM AUTHOR]