Carbon Quantum Dots Research Articles

Synthesis of hydrothermal-assisted papaya peel-derived carbon quantum dots impregnated carboxymethyl cellulose and pectin crosslinked nanohydrogel for shelf-life enhancement of strawberry.

This study focuses on utilizing papaya peel to produce carbon quantum dots (PP-CQDs) via a hydrothermal method and the PP-CQDs are subsequently embedded into carboxymethyl cellulose and pectin nanohydrogel to enhance the shelf-life of strawberries. The synthesis of PP-CQDs was found to be optimal under conditions of 12 h and 200 °C, resulting in a quantum yield of 39.15 % and an average particle size of 4.16±0.07 nm. The PP-CQDs had intense blue luminescence and a peak absorbance at 262 nm when exposed to UV light. They also displayed unique fluorescence emission at 260 nm and excitation at 526 nm. Particle size was not significant for both control (176.4 ± 0.18 nm) and PP-CQDs embedded nanohydrogel (175.8 ± 0.09 nm). The PP-CQDs nanohydrogel composite demonstrated high cell viability (95.12±0.78 to 98.43±0.96 %) as well as excellent antibacterial efficacy against pathogenic Staphylococcus aureus bacteria during time-kill and anti-quorum activity. Both types of coated strawberries exhibited non-significant differences in weight loss (16.85±0.18 and 16.34±0.39 %) as compared to uncoated strawberries (20.87±0.42 %) during storage. The firmness of both coated strawberries was found to be significantly higher as compared to uncoated samples, while strawberries coated with composite nanohydrogel showed enhanced microbial stability. Overall, PP-CQDs embedded nanohydrogel could be a promising coating material to enhance the shelf-life of highly perishable fruits.

Dual-functional ratiometric fluorescence sensor based on silica spheres for highly selective detection of Hg2+ and Fe3+

Ratiometric fluorescence sensors, which validate the absence of ambient and excitation light intensity effects, have attracted significant attention. In this study, a novel nanohybrid dual-emission system was fabricated by combining nitrogen-doped carbon quantum dots (NCQDs) with 8-hydroxyquinoline (8-HQ). This system allows for the simultaneous detection of Fe3+ and Hg2+ ions by utilizing distinct signals. A ternary hollow structure nanosensor containing core-shell silica spheres modified by 8-HQ molecules and decorated with carbon quantum dots was fabricated by subsequent solvothermal synthesis. The designed nanohybrid emits dual-emission fluorescence peaks at 480 and 340nm, originating from the intrinsic structure of NCQDs and 8-hydroxyquinoline, respectively. When Hg2+ is present, only the fluorescence intensity at 480nm is noticeably reduced. However, in the presence of Fe3+ ions, the fluorescence intensity at 480nm remains mostly unchanged, but clear fluorescence quenching is detected at 340nm. There was a linear relationship between fluorescence intensity ratios at 340 and 480nm and the concentration of Hg2+ and Fe3+, with detection limits of 9.50nM and 0.96μM, respectively. Furthermore, it demonstrated satisfactory assay performance in quantifying the mercury content in amalgam alloy and the Fe3+ concentration in a water sample. The results of this study offer a new approach to designing multifunctional fluorescent sensors and a potential application for biomedicine and environmental monitoring.

Facile synthesis of CQD/g-C3N4 as a highly effective metal-free photocatalyst for the degradation of carmoisine and indigo carmine dye

The development of extensive dye pollution in the water ecosystem seriously endangers the health of the living organism. For effectively eradicating dyecontaminants from water bodies, photocatalysis is consideredan effective, energy-consumption, inexpensive disinfection technique. As an alternative to conventional metal-based catalysts, heterogeneous metal-free photocatalysts are more sustainable and kinder to the environment. Here, we reported the simplehydrothermalchemical production of Carbon Quantum dots (CQD)-doped graphitic carbon nitride(GCN). Analytical instruments such as XRD, SEM, FE-SEM, HR-TEM, EDX, FT-IR, thesurface area of BET analysis, photoluminescence, and UV–vis spectroscopy, zeta potentialwere used to characterize the as-prepared CQD doped GCN (CDCN). The degradation studies reveal that the CDCN catalyst displays the highest rate of degradation performance than pure GCN. Within 60 min, it shows 96 % degradation toward indigo Carmine (IC) and 93 % decomposition towards carmoisine dye (CM). Significant e−/h+ separation, an increased surface area, and a high redox potential capacity to induce charge bears may all contribute to the CDCN catalyst’s enhanced photocatalytic degradation efficiency. The efficiency of the photocatalytic process was optimized by studying and altering many variables. These include Dye concentration, catalyst concentration, and variation of the pH solution were some of these. The nanocomposite exhibited excellent stability after three successive runs of the photocatalytic procedure. According to the kinetics analysis results indicate that the photocatalytic decomposition of Indigo Carmine (IC) and carmoisine (CM) dye follows pseudo-first-order kinetics. For better photodegradation performance, a potential photocatalytic method employing several pairs of electron-hole acceptor scavengershas been put forth. Based on the positionsof the band gap and the result of the characterization, a feasible mechanismpathway for charge carriers was also presented.

Solid/liquid hybrid lubrication behaviors of amorphous carbon film coupling with nonpolar and polar base oils

The amorphous carbon film (a-C) has aroused intensive interest in solid-oil hybrid lubrication design due to its low friction, high wear resistance, and good chemical inertness. However, the solid/liquid hybrid lubrication behaviors and mechanisms of a-C films when coupled with nonpolar and polar oils of similar viscosity are still insufficiently understood and ambiguous to date. In this study, we compared the lubrication properties of nonpolar paraffin oil and polar polyether oils with different molecular structures when combined with a-C film. The results demonstrated that the lubrication performance of polyether oils coupled with a-C film surpassed that of paraffin oil across various lubrication regimes. Notably, the stable superlubricity (friction coefficient<0.01) was achieved under mixed lubrication regime on the a-C film when coupled with polyethylene glycol (PEG) oil after a prolonged sliding duration. The tribo-induced formation of carbon quantum dots (CQDs) at the steel/a-C friction interface lubricated by PEG oils was firstly observed. The hydroxylation of the counter ball surface and the fabrication of CQDs might jointly contribute to the achievement of the robust superlubricity of the PEG oil/a-C film hybrid lubrication system.

Preparation and performance of self-cleaning synergistic visible light catalytic coatings based on N-CQDs/Bi2WO6 for NO degradation

Due to the intensification of nitric oxide (NO) emissions caused by industrial development, visible light responsive photocatalysts have been selected and applied in building coatings as a new strategy. In this study, N-doped carbon quantum dots (N-CQDs)-Bi2WO6 (NBW) was prepared using an ethylene glycol-assisted solvothermal method. Various techniques, including XRD, FT-IR, SEM, were employed to analyze and characterize NBW. The photocatalytic performance and stability of NBW were evaluated, and the results showed that 52% of NO (Initial concentration: 600 ppb) were oxidized under visible light. NBW was dispersed in an ethyl acetate/polytetrafluoroethylene (PTFE)/polyvinylidene fluoride (PVDF) suspension and modified by 1H,1H,2H,2H-Perfluorodecyltriethoxysilane (PFDTES), to form an easy-to-spray coating referred to as CPFB. Due to the photocatalytic ability of NBW, CPFB oxidized 74% of NO under visible light and reduced the coloring of coating surfaces contaminated with methyl red. The superhydrophobicity of CPFB coating provided the foundation for its self-cleaning ability. In addition, CPFB exhibited hydrophobicity and photocatalytic performance even after tests such as photooxidation, water impact, and wear. Finally, the photocatalytic mechanism of CPFB self-cleaning coating was explored. The significance of CPFB lied in its ability to effectively combine self-cleaning, visible light-responsive photocatalysis, and durability in a single coating. This innovative approach may inspire the development of similar coatings for various applications.

Synthesis and assessment of fenugreek carbon quantum dots as novel green scale inhibitor

Synthesis and assessment of fenugreek carbon quantum dots as novel green scale inhibitor

Magnesium-Doped Carbon Quantum Dot Nanomaterials Alleviate Salt Stress in Rice by Scavenging Reactive Oxygen Species to Increase Photosynthesis.

Salt stress has strongly impacted the long-term growth of eco-friendly farming worldwide. By targeting the oxidative stress induced by salt, the utilization of biomass-derived carbon dots (CDs) that possess high-efficiency antioxidant properties, are nontoxic, and have excellent biocompatibility represents a viable and effective approach for enhancing the salt tolerance of plants. In this study, we blended magnesium oxide nanoparticles with carbon sources derived from durian shells to construct Mg-doped carbon dots (Mg-CDs) through a hydrothermal reaction. We demonstrated that the foliar application of 150 μg/mL Mg-CDs to rice plants after treatment with 100 mM salt effectively increased the plant height (9.52%), fresh weight (22.41%), dry weight (33.33%), K+ content (21.46%), chlorophyll content (36.21%), and carotenoid content (16.21%); decreased the malondialdehyde (MDA) (9.43%), Na+ (25.75%), H2O2 (17.50%), and O2•- contents (37.99%); and promoted the photosynthetic system and antioxidant activity. Transcriptome analysis revealed that Mg-CD pretreatment triggered transcriptional reprogramming in rice seedlings. The enrichment analysis of the Kyoto Encyclopedia of Genes and Genomes pathways based on trend groups of gene expression patterns of Profile 8 and Profile 15 indicated that priming with Mg-CDs activated stress signaling- and defense-related pathways, such as metabolic pathways, biosynthesis of secondary metabolites, and photosynthesis pathways. These activations subsequently prompted the expression of genes related to the mitogen-activated protein kinase signaling pathway, hormone signal transduction, the oxidative stress response, and the photosynthetic system. This study demonstrated that the use of Mg-CDs represents a potential strategy to increase plant salt tolerance, creating the possibility for the regulation of crop salinity stress and offering valuable advancements in sustainable agriculture.

High acid-base tolerance and long storage time lanthanum cerium co-doped carbon quantum dots for Fe3+ detection

In this paper, lanthanum and cerium co-doped carbon quantum dots (LaCe-CQDs) was firstly synthesized by one step hydrothermal method. The obtained LaCe-CQDs shown sable fluorescence properties with pH values from 3 to 9 and after 4 weeks of storage. The average particle size of LaCe-CQDs, with excitation and emission wavelengths of 350 nm and 446 nm, is 3.27 ± 0.12 nm. Selective analysis of various metal ions revealed the sensitivity of LaCe-CQDs towards Fe3+ ions. Within the 0–60 μM, the fluorescence intensity exhibits a strong linear correlation with the concentration of Fe3+. The limit of detection (LOD) was determined to be 0.753 μM. Additionally, the accuracy of LaCe-CQDs were demonstrated in natural water samples. Therefore, LaCe-CQDs are a promising sensor for Fe3+ detection.

Ultrathin metal–organic framework synergizes with carbon quantum dots improving photoelectrochemical water oxidation and tetracycline hydrochloride degradation performance

Ultrathin metal–organic framework synergizes with carbon quantum dots improving photoelectrochemical water oxidation and tetracycline hydrochloride degradation performance

Utilization of Biodiesel Residue through Efficient Microwave-Assisted Synthesis of Carbon Quantum Dots: A Versatile Nanomaterial for Environmental Remediation

The rapid expansion of the biodiesel industry has substantially increased crude glycerol residue (CG) production, creating sustainability and economic challenges due to surplus glycerol generation. Conventional purification methods are costly and environmentally demanding, necessitating innovative strategies to utilize this residue effectively. This study innovates by exploring the microwave-assisted synthesis of carbon dots (CDs) from CG, exemplifying a shift toward sustainable biodiesel production by transforming the residue into a multifunctional material. CDs exhibited a nanometric spherical morphology of 2.6 ± 0.3 nm diameter verified by HRTEM analysis. The reduction of oxygen confirmed the transformation of CG into CDs–H bands and the formation of polyaromatic structures. The graphitic structures were verified by Raman spectroscopy, electron paramagnetic resonance, and X-ray diffraction. The quantum yield (QY) was calculated to be 1.3%. The multifunctionality of CDs has been proven in sensing and photocatalysis. In the sensor applications, the CDs demonstrated strong fluorescence quenching in the presence of Fe3+ and Cu2+ ions, with a limit of detection of 1.8 ± 0.01 and 4.0 ± 0.04 mg.L-1, respectively, indicating the potential use of CDs in detecting these ions in wastewater samples. When complexed with titanium dioxide (TiO2), the TiO2/CDs composite showed an extended photoresponse of TiO2 to the UV-visible region, improving the efficiency of photocatalytic reactions for Victoria Blue B (VBB) dye degradation (98% degradation after 150 min). This research highlights the potential of utilizing CG to produce versatile CDs, contribute to more sustainable biodiesel production, and offer promising applications in environmental sensing and photocatalysis.

Tribological properties of polyimide coating filled with solvent-free covalent carbon quantum dots nanofluids

Novel organic coatings were developed by incorporating solvent-free covalent carbon quantum dots nanofluids (CQDs NFs) into a polyimide (PI) matrix. The tribological properties of CQDs NFs/PI composite coatings were tested using a ball-on-disk tribometer, revealing that even a low loading of CQDs NFs significantly improved tribological performance of PI. Molecular dynamics (MD) simulations and nanoindentation tests showed that CQDs NFs restricted PI molecular chain movement, enhancing mechanical properties. Additionally, CQDs NFs promoted the formation of stable transfer films on steel surfaces, improving wear resistance. This study confirms CQDs NFs' effectiveness in modifying PI composite coatings' friction and wear properties.

Enhancing nanomedicine with doped carbon quantum dots: a comprehensive review

Enhancing nanomedicine with doped carbon quantum dots: a comprehensive review

Enhancing Indoor Photovoltaic Performance of Inverted Type Organic Solar Cell by Controlling Photoactive Layer Solution Concentration

With the development of various low-power indoor electronic devices, indoor photovoltaics, particularly organic solar cells (OSCs) have attracted a lot of interest in recent years. Increasing the light absorption and suppressing the leakage current are pivotal to improve the indoor photovoltaic performance of OSCs. In this study, the carbon quantum dots (CQDs)-incorporated photoactive layer solution concentration was varied to improve the photovoltaic performance under 1-sun and indoor white LED illumination. The photoactive layer was composed of (6,6)-phenyl-C61-butyric acid methyl ester) (PCBM) as the acceptor and poly(3-hexylthiophene) (P3HT) as the donor. The ZnO electron transport layer was deposited on fluorine-doped tin oxide (FTO)-coated glass substrates using a spin coating technique. The photoactive layers with different solution concentrations were spin coated on top of the ZnO layer. For device completion, silver anode was thermally evaporated. It is interesting to find that the optimum solution concentration obtained under white LED illumination is larger than that under 1-sun illumination. The maximum power conversion efficiency (PCE) of 0.95% was obtained under 1-sun illumination for device with the solution concentration of 36 mg/mL, whereas, under white LED illumination, the highest PCE of 3.59% was obtained for the device with solution concentration of 48 mg/mL.The discrepancy is ascribed to the higher light absorption of thicker photoactive layer and less significant charge recombination loss under weak light intensity. This study highlights the importance of using different optimization strategies to improve the photovoltaic performance of OSCs for outdoor and indoor applications.

Regulatory mechanism of grafted alkyl chain length of carbon quantum dots as additives on the tribological properties of lithium greases

Carbon quantum dots (CQDs) exhibit exceptional structural properties and minimal environmental impact, garnering significant interest in the field of lubrication. In this study, four types of modified CQDs with varying alkyl chain lengths were synthesized through hydrothermal methods and subsequently mixed with lithium grease (LG) to formulate mixed greases. The influence of the alkyl chain length on the CQDs used as additives in the mixed greases was investigated with a four-ball friction and wear tester, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). Specifically, compared to pure LG, the modified CQDs with the shortest alkyl chain length reduced the coefficient of friction (COF), the diameter of abrasive spots, and the depth of abrasive scars by 33.65%, 42.11%, and 51.87%, respectively. This improvement can be attributed to the ease of these shorter-chain CQDs entering the contact area and forming a stable film containing carbon, nitrogen, and oxygen elements through friction. The tribological properties of modified CQDs can be effectively controlled by adjusting the length of the carbon chain, providing a theoretical basis for the design of environmentally friendly and sustainable grease additives in engineering applications.

Synergistic Integration of Carbon Quantum Dots in Biopolymer Matrices: An Overview of Current Advancements in Antioxidant and Antimicrobial Active Packaging.

Approximately one-third of the world's food production, i.e., 1.43 billion tons, is wasted annually, resulting in economic losses of nearly USD 940 billion and undermining food system sustainability. This waste depletes resources, contributes to greenhouse gas emissions, and negatively affects food security and prices. Although traditional packaging preserves food quality, it cannot satisfy the demands of extended shelf life, safety, and sustainability. Consequently, active packaging using biopolymer matrices containing antioxidants and antimicrobials is a promising solution. This review examines the current advancements in the integration of carbon quantum dots (CQDs) into biopolymer-based active packaging, focusing on their antioxidant and antimicrobial properties. CQDs provide unique advantages over traditional nanoparticles and natural compounds, including high biocompatibility, tunable surface functionality, and environmental sustainability. This review explores the mechanisms through which CQDs impart antioxidant and antimicrobial activities, their synthesis methods, and their functionalization to optimize the efficacy of biopolymer matrices. Recent studies have highlighted that CQD-enhanced biopolymers maintain biodegradability with enhanced antioxidant and antimicrobial functions. Additionally, potential challenges, such as toxicity, regulatory considerations, and scalability are discussed, offering insights into future research directions and industrial applications. This review demonstrates the potential of CQD-incorporated biopolymer matrices to transform active packaging, aligning with sustainability goals and advancing food preservation technologies.

Carbon quantum dots in breast cancer modulate cellular migration via cytoskeletal and nuclear structure

Carbon 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.

N, S-Codoped Carbon Quantum Dots with High Inhibition Efficiency: Implications for Corrosion Mitigation of Carbon Steel in Acidic Environments.

The environmental friendliness, economic feasibility, and high efficiency of carbon quantum dots (CQDs) render them as highly promising candidates for corrosion inhibitors. The present study proposed the fabrication of nitrogen- and sulfur-codoped CQDs via an one-step hydrothermal method using l-cysteine and 4-aminosalicylic acid as precursors. The structure, particle size, and surface ligands of the prepared CQDs were determined through spectroscopy and transmission electron microscopy characterization. Subsequently, the inhibition performance of the CQDs on carbon steel in a 0.5 M sulfuric acid solution was evaluated through weight loss measurement, electrochemical methods, and surface analysis. The CQDs exhibited remarkable inhibition efficiencies of 97.9% at 293 K and 98.9% at 313 K, with a concentration of 150 ppm. In addition, the obtained CQDs demonstrated a combined physisorption and chemisorption adsorption behavior, which complied with the Langmuir adsorption isotherm. These findings provide insight into the inhibition mechanism and highlight the potential of codoped CQDs for corrosion mitigation applications in acidic environments.

The impact of carbon quantum dots derived from spent coffee grounds on the droplet combustion of diesel/n-butanol blend

As global concerns surrounding climate change mount and fossil fuel reserves diminish, the application of additives in internal combustion engines is increasingly prevalent. Butanol and carbonaceous nanomaterials, such as carbon quantum dots (CQD), are being employed as additives to increase engine efficiency and mitigate the emission of pollutants. Nevertheless, understanding the impact of these additives on combustion behavior at the droplet scale through combustion assessments before their use in engines is crucial. In this study, our main objective was to assess the impact of incorporating CQD dispersed in n-butanol as additives to conventional diesel fuel on the combustion characteristics at the droplet scale. CQD were obtained from spent coffee grounds (SCGs) using n-butanol as a solvent. The product obtained was mixed with Colombian commercial diesel (10 % vol. palm oil biodiesel), and its combustion was evaluated using the droplet combustion method. Before the CQD synthesis, SCGs were characterized by thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM). CQD were characterized via Fourier transform infrared (FTIR) spectroscopy, Transmission Electron Microscopy (TEM), UV–vis, and fluorescence spectroscopy. Results indicated that adding n-butanol and CQD to commercial diesel leads to a 5.4 % and 16.5 % increase in droplet ignition delay, respectively. These additives also cause droplet contraction and expansion cycles, resulting in unstable combustion. However, CQD reduces the frequency of microexplosions caused by boiling n-butanol inside the droplet, which mitigates instabilities during droplet combustion. Including CQD can enhance fuel evaporation by increasing the density of nucleation sites for bubble formation and preventing micro-explosions, thereby leading to stable combustion. These attributes can significantly influence the performance of blends in Compression Ignition (CI) Engines.

Characterization of green-synthesized carbon quantum dots from spent coffee grounds for EDLC electrode applications

This study investigates the green synthesis of carbon quantum dots (CQDs) from spent coffee grounds using a hydrothermal method, offering an eco-friendly, cost-effective, and straightforward approach to nanomaterial production. The synthesized CQDs, with particle sizes ranging from 1.6 to 4.4 nm, exhibited notable fluorescence, achieving quantum yields of 37.0 %, 54.3 %, and 63.3 % depending on the coffee source. Characterization technique, including XRD, FTIR, SEM, TEM, and BET, confirmed their structural suitability of these CQDs for energy storage applications. Their electrochemical performance was evaluated through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). Among the CQDs tested, those derived from spent Liberica coffee ground (medium roasted) demonstrated superior performance, with a discharging specific capacitance of 97.5 F/g, an energy density of 4.3 Wh/kg, and a power density of 130.6 W/kg at a current density of 0.5 A/g. Additionally, they exhibited acceptable internal resistance (Ra = 0.01 kΩ and Rab = 16.9 kΩ), indicating favourable charge transfer characteristics. These results underscore the enhanced energy storage potential of CQDs derived from spent coffee grounds. The findings not only highlight the excellent electrochemical performance but also support the viability of biomass waste as a valuable resource for advanced energy storage applications, promoting sustainable, eco-friendly technologies.

Identification of peripheral nerve functional fascicles in Sprague-Dawley rats by the carbon quantum dot-Annexin V antibody complex

To explore a method to identify the sensory and motor fascicles of the peripheral nerve to achieve accurate peripheral nerve functional fascicle suture. The peripheral nerve Sunderland V injury model, muscle branch of the femoral nerve and saphenous nerve were established in the bilateral femoral nerves of Sprague-Dawley (SD) rats. The specific samples were grouped as follows: the main trunk of the femoral nerve was exposed bilaterally and cut with microscopic scissors in the main trunk of the femoral nerve to prepare a model of Sunderland V injury in the mixed fascicle of peripheral nerves; the muscle branch of the femoral nerve was exposed bilaterally and cut in the middle section of the muscle branch of the femoral nerve to prepare a model of Sunderland V injury in the motor fascicle of peripheral nerves; the saphenous nerve was exposed bilaterally and cut at 1 cm below the patella to prepare a model of Sunderland V injury to the sensory fascicle of the peripheral nerves. A carbon quantum dot (CD)-annexin V antibody complex was prepared and applied to the distal and proximal nerve stumps of the peripheral nerve Sunderland V injury model groups of SD rats. Under the excitation light source of a 380 nm uv lamp, fluorescence color development was observed under a fluorescence microscope after 5, 10, 15, and 20 min. At 5 min, sections of the bilateral femoral nerve trunk, muscular branches of the femoral nerve, and Sunderland V lesion of the saphenous nerve in SD rats were only dark in color under the microscope, and there was no difference in fluorescence. The intensity of the staining increased significantly for 10–20 min. The sensory fascicles and saphenous nerves of the femoral nerve trunk showed blue fluorescence under the CD-Annexin V antibody complex staining, while the motor fascicles and muscle branches of the femoral nerve trunk showed no fluorescence. Fluorescence intensity gradually decreased after 20 min of staining. There was no significant difference in the staining intensity at 5, 10, 15, and 20 min in each group. Our results suggest that the CD-Annexin antibody complex can be used to identify functional fascicles of peripheral nerves in SD rats.