Synthesis Of Fluorescent Carbon Dots Research Articles

Effective synthesis of fluorescent carbon dots and their application in controllable detection of deferasirox

As an iron chelation therapy, deferasirox (DEF) is commonly used as the primary treatment drug to prevent intracellular iron overload in patients with thalassemia who require long-term and large blood transfusions. However, due to the toxic side effects of long-term use, building a convenient and sensitive DEF detection method remains an important task. This study developed a simple and effective fluorescence detection strategy for DEF based on the coordination effect of DEF and Cu2+ (DEF-Cu). The high quantum yield N-doped blue emission carbon dots (CDs) synthesized by a simple one-step hydrothermal method were applied as the fluorescent probe. The DEF-Cu exhibited a new absorption peak centered at 334 nm, overlapping with the absorption wavelength of CDs, resulting in an internal filtration effect (IFE) for quenching the fluorescence of CDs. The quenching degrees of CDs caused by DEF-Cu showed a good linear relationship in the range of 0.5–20 μg/mL, with a detection limit (LOD) as low as 0.12 μg/mL. The accurate detections of DEF in dispersible tablets and plasma were also achieved. This strategy not only enriched the understanding of the properties of target drugs but also provided valuable insights for designing CDs with specific luminescent properties and applying them to distinctive methods for drug analysis.

Green synthesis of fluorescent carbon dots from waste chicken feathers for chlortetracycline sensing

Herein, we present a novel, straightforward, eco-friendly and cost-effective method for synthesizing fluorescent carbon dots. A simple one-pot hydrothermal method was used to create blue-emitting nitrogen-doped carbon dots (N-CDs) from waste chicken feathers and ammonium chloride (NH4Cl) as precursors. The research demonstrates that N-CDs not only exhibit excellent photostability, but also serve as a versatile nanoscale fluorescence sensor for the efficient qualitative and quantitative detection of chlortetracycline (CTC) in samples. The mechanism of fluorescence quenching is attributed to the specific and rapid quenching of N-CDs fluorescence by chlortetracycline through the static quenching and inner filter effect (IFE). The concentration of CTC within the range of 0.05–0.35 mM exhibits a significant linear relationship with the fluorescence quenching of NCDs, as indicated by the formula (I0-I)/I = 4.74248c(CTC)-0.09041. Subsequent spiked recovery experiment confirms the feasibility of this method for the detection of CTC in samples. Therefore, leveraging the concept of turning waste into treasure, this study successfully developed a green and cost-effective method for synthesizing NCDs from natural biomass, offering a novel perspective for further development of multifunctional sensors.

Synthesis of Fluorescent Carbon Dots from Raw Materials: An Overview of Textile Applications

Synthesis of Fluorescent Carbon Dots from Raw Materials: An Overview of Textile Applications

Green synthesis of fluorescent carbon dots from ascorbic acid and their application in sensing and biological imaging

A simple, highly efficient, and environmentally friendly one-step method has been developed to synthesize fluorescent carbon dots (CDs) with the assistance of hydrogen peroxide (H2O2). Here H2O2 acts as a green accelerator to promote the preparation of CDs, while temperature plays a critical role in controlling the entire synthesis process. The prepared CDs demonstrate monodispersion, with an average diameter of ∼6.8 nm, superior stability, and excitation-dependent photoluminescent (PL) behavior. The PL mechanism of the CDs was investigated using time-resolved PL decay, revealing that the PL originates from both the defect state and the intrinsic state of the CDs. Furthermore, the CDs show significant promise as pH sensors and versatile nanothermometry devices, owing to their remarkable sensitivity to both pH and temperature, as demonstrated by the pronounced dependence of their steady-state fluorescence emission spectra. It’s worth noting that temperature and pH sensors present significant reversibility, sensitivity, and linearity. More importantly, the CDs display low cytotoxicity, good biocompatibility, and the ability to enter human breast cancer Bcap-37 cells, making them highly suitable candidates for cellular imaging and labeling.

Facile Synthesis of B/P Co-Doping Multicolor Emissive Carbon Dots Derived from Phenylenediamine Isomers and Their Application in Anticounterfeiting.

Carbon dots (CDs) possess a considerable number of beneficial features for latent applications in biotargeted drugs, electronic transistors, and encrypted information. The synthesis of fluorescent carbon dots has become a trend in contemporary research, especially in the field of controllable multicolor fluorescent carbon dots. In this study, an elementary one-step hydrothermal method was employed to synthesize the multicolor fluorescent carbon dots by co-doping unique phenylenediamine isomers (o-PD, m-PD, and p-PD) with B and P elements, which under 365 nm UV light exhibited signs of lavender-color, grass-color, and tangerine-color fluorescence, respectively. Further investigations reveal the distinctness in the polymerization, surface-specific functional groups, and graphite N content of the multicolor CDs, which may be the chief factor regarding the different optical behaviors of the multicolor CDs. This new work offers a route for the exploration of multicolor CDs using B/P co-doping and suggests great potential in the field of optical materials, important information encryption, and commercial anticounterfeiting labels.

Chicken egg white as a “greener” biomass source for the rapid synthesis of fluorescent carbon dots

Most of the methodologies reported to fabricate fluorescent carbon dots (CDs) are not fully sustainable. Here, we report the “green” optimization of our base catalysis method; by using chicken egg white powder, we obtained CDs with a 25.6% fluorescence quantum yield in a one-step synthesis that completes in 6 h and do not require any purification. This improved methodology is faster, cheaper and has a better mass and solvents economy, so it is way “greener”. The effect of three hydroxides was studied and z-potential, UV–Vis, fluorescence and FTIR spectroscopies, and TEM were used as characterization techniques.

Synthesis of Fluorescent Carbon dots using Bio-waste Powder for Photo-degradation of Dyes: Simulation and Mechanistic Study

Biowaste-derived carbon quantum dots (CQDs) offer wide range of applications including bioimaging, sensor, photo detector, photo sensive applications and drug degradation. However, an inaccurate measurement of their quantum confinement and...

Synthesis of fluorescent carbon dots by B/P doping and application for Co2+ and methylene blue detection

During the synthesis of carbon dots, different heteroatom doping can change the fluorescence color and the emission wavelength when the same precursor is applied. In this study, we used o-phenylenediamine and L-lysine as raw materials, boric acid or phosphoric acid as different heteroatom dopants, and water as solvent to synthesize doped carbon dots through a simple microwave-assisted method. Finally, two kinds of doped carbon dots with different fluorescence colors under 365 nm UV light were obtained, of which the B-doped carbon dots (B-CDs) showed orange fluorescence, and the P-doped carbon dots (P-CDs) showed red fluorescence. Both carbon dots had satisfactory fluorescence quantum yields and can be used as fluorescence probes. Therefore, we investigated the detection performance of these two carbon dots when they were used as fluorescent probes. B-CDs can selectively detect Co2+ with a detection limit of 0.1102 μM, and at the same time, it can realize the naked eye detection of Co2+ in a certain concentration range. The P-CDs could sensitively detect methylene blue with a detection limit of 0.048 μM.

Green synthesis of fluorescent carbon dots from discarded cigarette butts as an effective fluorescence probe for sensing iron ions

A green synthesis method for preparing fluorescent carbon dots (CDs) from discarded cigarette butts was described. This method reduces costs and environmental pollution and is fully in line with the development of green chemistry. The as-synthesized CDs can be designed as a fluorescent probe for detecting iron ions (Fe3+) with highly selective and sensitive detection in the range of 0.5–800 μM. The reliability of the proposed probe was studied using tap water as a real sample, and satisfactory results were obtained.

Green synthesis of fluorescent carbon dots from Robinia hispida L. leaves for selective detection of Hg (II)

In this study, Robinia hispida L leaves (RH) was used as a precursor for the first time to synthesize fluorescent carbon dots (CDs) with stable blue fluorescence by a single-step hydrothermal synthesis method. Notably, the innovative approach eliminates the necessity for toxic chemicals or hazardous substances, marking a significant advancement in the field. The synthesized CDs demonstrate CDs demonstrates the predominance of spherical shapes with an average size of 11.63 ± 1.92 nm. The CDs not only exhibit an enhanced fluorescent efficiency with a relatively high quantum yield of up to 6.8%, but they also possess the potential for direct utilization in the selective determination of Hg(II) through fluorescence quenching, even without any functionalization. Under the optimized conditions at a pH of 7.0, a robust linear correlation was found to exist between the fluorescence intensity and the concentration of Hg (II) within the range of 5–17.5 μM, exhibiting a detection limit (3σ) of 1.5 μM. Additionally, this methodology was effectively employed to successfully detect Hg (II) ions in various aqueous samples, including tap water, spring water, drinking water, and a certified reference material (CRM-SA-C Sandy Soil C). The spike recoveries of 97.6%–101.6% with less than 2.7% variability were performed on all samples.

Hydrothermal synthesis of fluorescent carbon dots from myrrh residue for Fe3+ detection and antioxidant application

Hydrothermal synthesis of fluorescent carbon dots from myrrh residue for Fe3+ detection and antioxidant application

Synthesis of Fluorescent Carbon Dots from Soybean Residuals Using Hydrothermal Method

Soybean residuals are biowaste composed of carbon chains and amine groups bounded in peptide linkages. The component was identified through FTIR analysis which showed the vibration of the diamide bond (N=C=N) at wave number 2132cm-1. Owing to the existence of these components, soybean has the potential to be used as a precursor to synthesize carbon nano-material, such as Carbon Dots (C - Dots). In this study, the synthesis of C - Dots material from soybean residuals was carried out using the facile hydrothermal method at a temperature of 200 oC for 6 hours. Afterward, the as-synthesized C - Dots were analyzed for their optical property, structure, and morphology. Based on the analysis of the UV - Vis and photoluminescent spectra, C - Dots exhibited absorbance peaks of 292 nm and 301 nm in the UV light region, and fluorescence emission peaks of 468 nm, with blue luminescence characteristics. The observation was supported by the morphological analysis using the HR - TEM, C - Dots exist in a spherical shape with an average particle size of 3.467 nm and a lattice distance of 0.363 nm. Besides, the C - Dots exhibited a good quantum yield of 28.15 %. From the results of the analysis, it is known that the synthesis of C - Dots material has been successfully carried out with particle size < 10 nm.

Synthesis of Fluorescent Carbon Dots (CDs) Using Laser Ablation Method for Bioimaging Application

Carbon Dots (CDs) were synthesized using laser ablation by focusing the laser beam on carbon (Tea) material in colloid (CH3) for 3 hours. UV-Vis spectroscopic and fluorometric characterization showed absorption of the wavelength peaks caused by the control treatment and after laser ablation and coating using Poly Ethylene Glycol (PEG400). The excitation and emission energies are formulations of CDs absorbance wavelength and fluorescence intensity. The absorbance coefficient is obtained based on the absorbance value of the cuvette thickness. The transmittance value (T) is obtained based on the absorption coefficient multiplied by 100%. CD fluorescence wavelength based on control parameters was 489 nm. After laser ablation was 496 nm, and after coating was 511 nm. CDs morphology and size characteristics are 4 nm to 10 nm based on TEM measurements. Fluorescence analysis for bioimaging applications on the luminescence intensity value of internalized blue CDs in zebrafish eye organs. The average intensity of CDs in the eye organs, gill, intestinal, dorsal, and tail injection points was 88.15 %, 91.58 %, 92.76 %, and 0.00 %.

Green Synthesis of Fluorescent Carbon Dots from Annona squamosa Leaves: Optical and Structural Properties with Bactericidal, Anti-inflammatory, Anti-angiogenesis Applications.

A hydrothermal method was employed for green synthesis of fluorescent carbon dots (GCDs) from Annona squamosa leaves. The synthesized GCDs were confirmed by microscopic and spectroscopic techniques such as: High Resolution Transmission Electron Microscopy (HR-TEM), Atomic Force Microscopy(AFM), UV-Vis spectrometry, Fluorescence spectrometry, X-Photoelectron Spectroscopy(XPS), X-ray Diffraction spectroscopy(XRD), and Fourier Transform Infrared Spectroscopy(FTIR). The produced GCDs had shown multiple properties, including massiveantibacterial activity at concentration 200μg/ml. The stabilization of human red blood cells served as a method to assess the anti-inflammatory activity. We also looked at how GCDs affected the angiogenesis process. The density of blood vessels wassignificantly decreased after treatment with GCDs, according to the results of the Chorio-Allantoic Membrane assay (p < 0.05). As per the study prepared GCDs from fallen leavesofAnnona squamosahave multifunctional applications.

Biogenic Synthesis of Fluorescent Carbon Dots (CDs) and Their Application in Bioimaging of Agricultural Crops.

Fluorescent nanoparticles have a transformative potential for advanced sensors and devices for point-of-need diagnostics and bioimaging, bypassing the technical burden of meeting the assay performance requirements. Carbon dots (CDs) are rapidly emerging carbon-based nanomaterials. Regardless of their fate, they will find increasing applications. In this study, a simple approach for synthesizing CDs from fruit peels was developed. The CDs were fabricated from Annona squamosa (L.) peels using a carbonization technique through microwave-assisted hydrothermal digestion at temperatures around 200 °C. Synthesized CDs were detected using a UV transilluminator for the preliminary confirmation of the presence of fluorescence. UV-Vis spectrophotometry (absorbance at 505 nm) analysis, zeta potential measurement (-20.8 mV), nanoparticles tracking analysis (NTA) (average size: 15.4 nm and mode size: 9.26 nm), photoluminescence, and Fourier transform infrared (FT-IR) analysis were used to identify the capping functional groups on the CDs. The total quantum yield exhibited was 8.93%, and the field emission scanning electron microscopy (FESEM) showed the size range up to 40 nm. The germinating mung bean (Vigna radiata (L.)) seeds were incubated with biogenically synthesized CDs to check the absorption of CDs by them. The fluorescence was observed under a UV-transilluminator in the growing parts of seeds, indicating the absorption of CDs during the germination, development, and growth. These fluorescent CDs could be used as a bioimaging agent. This novel method of synthesizing CDs was found to be eco-friendly, rapid, and cost-effective.

Low Temperature Synthesis of Fluorescent Carbon Dots from Pomegranate Peels

In recent times, much attention has been drawn to the synthesis of carbon dots from agro waste since they are a cheap source, readily available, non-toxic and in most instances disposed of as waste. Yet, the synthesis of fluorescent carbon dots at low temperatures from agro waste remain a challenge. Herein, we report for the first time on a sucessful synthesis of flourescent carbon dots, with average size 4.7 nm, at low temperature of only 100 °C using hydrothermal method from pomegranate peels as a sole precursor. The crystal structure and the morphological features of the synthesized dots were characterized by XRD, UV-vis absorption spectroscopy, photoluminescence (PL), nanosecond fluorescence lifetime, FTIR and Zeta potential measurments. The synthesized dots showed bluish emission at 440 nm, when excited at a wavelength of 360 nm, with relatively long decay lifetime of 7.4 ns.

Prepared carbon dots from wheat straw for detection of Cu2+ in cells and zebrafish and room temperature phosphorescent anti-counterfeiting

The green synthesis of fluorescent carbon dots from biomass is critical for their sustainable application. Herein, using wheat straw as a single precursor, carbon dots (CDs) were prepared through a one-step carbonization process, and the obtained CDs have intense blue luminescence and excitation-independent photoluminescent behavior. The solution of CDs shows good biocompatibility, and low cytotoxicity successfully used as hopeful bioimaging and biosensing probe for Cu2+ in HepG2 cells and zebrafish. Based on CDs, boron-doped carbon dots with IPA shells (CDs@IPA) can be obtained by doping boron element and isophthalic acid (IPA) coating. CDs@IPA irradiated with different wavelength ultraviolet lamps shows different solid fluorescence, while turning off the ultraviolet lamp can produce green visible room temperature phosphorescence (RTP) to the naked eyes for 5 s. The two kinds of wheat straw-based carbon dots have bifunctional luminescence properties and can be used to detect Cu2+ and serve as RTP anti-counterfeiting signs to ensure information security.

Green synthesis of fluorescent carbon dots from Annona Reticulata leaves as a sensor for Chromium (III) ions

In this work, we designed a green synthetic route to fabricate carbon quantum dot (CQD) from Annona reticulata leaves and developed it as a water-soluble, stable, and selective fluorescent probe for detecting Cr (III) ions. The generated CQDs exhibit an excitation dependent behaviour in the 280 to 400 nm range with high fluorescence quantum yield (QY) of 12 %. The UV–vis., FT-IR, fluorescence, TEM, and XRD techniques were used to characterize the optical, structural, and morphological properties of the CQDs. Fluorescence quenching of the CQDs in the presence of Cr (III) ions were utilized for the development of the sensor with the aid of PL analysis. We have optimized the reaction conditions such as pH and interaction time to maximize the selective detection ability of the sensor. The linear range and LOD obtained were 0 to 40 μM and 2 μM, respectively. A Stating quenching mechanism is involved in the quenching mechanism. Further, we investigate the ability of CQDs to detect Cr (III) ions in real water sample analysis.

Microwave-assisted synthesis and formation mechanism of fluorescent carbon dots from starch

We report the synthesis of fluorescent carbon dots (CDs) via the microwave (MW)-assisted hydrothermal treatment of starch in an aqueous phosphoric acid solution. CDs emitting blue, orange, and green fluorescence in different solvents were obtained. The fluorescence quantum yield of the CDs emitting blue fluorescence is 30%, which is comparable to those of semiconductor quantum dots. The formation of the CDs under MW irradiation was monitored using a spectroscopic approach. The formation of blue-fluorescent CDs began at an early stage of the reaction. Subsequently, the CDs underwent aggregation. The aggregations were effectively extracted to the toluene layer by liquid−liquid extraction, and they emitted orange fluorescence in toluene and green fluorescence in water. The formation of the aggregates was followed by a steep increase in the yield of the CDs that emit blue fluorescence. MW heating for a certain duration was required to increase the yield of the blue-fluorescent CDs.

Phosphoric acid assisted synthesis of fluorescent carbon dots from waste biomass for detection of Cr(VI) in aqueous media

A green and facile method for the synthesis of carbon dots (CDs) have been developed using lignocellulosic biomass (banana stem) and phosphoric acid to construct fluorescent sensor for Cr(VI) detection. The effects of phosphoric acid and temperature on the fluorescence behavior of carbon dots have been explored elaborately. The optical and structural properties of the CDs were determined by different characterization techniques. The prepared CDs display excellent fluorescence properties with intense bright blue emission spectra around 447 nm at an excitation wavelength of 350 nm. The CDs possessing the highest quantum yield (15.1%) have an immense sensing potential to detect Cr(VI) in linear detection range (10–30 μM) with detection limit of 2.4 μM. Furthermore, the CDs have been applied to quantitatively detect Cr(VI) in real water samples. Theoretical studies based on DFT and TDDFT calculations suggested the detection pathway of Cr(VI) occurs via photoinduced electron transfer (PET) which furthur supports the experimental studies.