RESUMEN
Sodium tripolyphosphate (STPP), as one of the many food additives, can cause gastrointestinal discomfort and a variety of adverse reactions when ingested by the human body, which is a great potential threat to human health. Therefore, it is necessary to develop a fast, sensitive and simple method to detect STPP in food. In this study, we synthesized a kind of nitrogen-doped carbon quantum dots (N-CQDs), and were surprised to find that the addition of STPP led to the gradual enhancement of the emission peaks of the N-CQDs, with a good linearity in the range of 0.067-1.96 µM and a low detection limit as low as 0.024 µM. Up to now, there is no report on the use of carbon quantum dots for the direct detection of STPP. Meanwhile, we found that the addition of Al3+ effectively bursts the fluorescence intensity of N-CQDs@STPP solution and has a good linear relationship in the range of 0.33-6.25 µM with a lower detection limit of 0.24 µM. To this end, we developed a fluorescent probe to detect STPP and Al3+. In addition, the probe was successfully applied to the detection of bread samples, which has great potential for practical application.
Asunto(s)
Carbono , Colorantes Fluorescentes , Aditivos Alimentarios , Límite de Detección , Polifosfatos , Puntos Cuánticos , Espectrometría de Fluorescencia , Puntos Cuánticos/química , Colorantes Fluorescentes/química , Aditivos Alimentarios/análisis , Espectrometría de Fluorescencia/métodos , Carbono/química , Polifosfatos/análisis , Polifosfatos/química , Aluminio/análisis , Nitrógeno/química , Pan/análisisRESUMEN
Low fluorescence under visible light excitation and catalytic activity limit many applications of graphene quantum dots in optical detection, biosensing, catalysis and biomedical. The paper reports design and synthesis of histidine, serine and folic acid-functionalized and boron and iron-doped graphene quantum dot (Fe/B-GQD-HSF). The Fe/B-GQD-HSF shows excellent fluorescence behavior and peroxidase-like activity. Excitation of 330 nm ultraviolet light produces the strongest blue fluorescence and excitation of 480 nm visible light produces the strongest yellow fluorescence. The specific activity reaches 92.67 U g-1, which is higher than that of other graphene quantum dots. The Fe/B-GQD-HSF can catalyze oxidation of 3,3',5,5'-tetramethylbenzidine with H2O2 to form blue compound. Based on this, it was used for colorimetric and fluorescence detection of H2O2. The absorbance at 652 nm linearly increases with the increase of H2O2 concentration between 0.5 and 100 µM with detection limit of 0.43 µM. The fluorescence signal linearly decreases with the increase of H2O2 concentration between 0.05 and 100 µM with detection limit of 0.035 µM. The analytical method has been satisfactorily applied in detection of H2O2 in food. The study also paves one way for design and synthesis of functional graphene quantum dots with ideal fluorescence behavior and catalytic activity.
Asunto(s)
Boro , Colorimetría , Ácido Fólico , Grafito , Histidina , Peróxido de Hidrógeno , Hierro , Puntos Cuánticos , Serina , Puntos Cuánticos/química , Grafito/química , Peróxido de Hidrógeno/análisis , Peróxido de Hidrógeno/química , Colorimetría/métodos , Ácido Fólico/análisis , Ácido Fólico/química , Hierro/análisis , Hierro/química , Boro/química , Histidina/análisis , Histidina/química , Serina/análisis , Serina/química , Espectrometría de Fluorescencia/métodos , Límite de Detección , Análisis de los Alimentos/métodos , Peroxidasa/química , Peroxidasa/metabolismo , CatálisisRESUMEN
In this study, the interaction of the human hemoglobin with cost effective and chemically fabricated CdS quantum dots (QDs) (average sizes ≈3nm) has been investigated. The semiconductor QDs showed maximum visible absorption at 445 nm with excitonic formation and band gap of ≈ 2.88 eV along with hexagonal crystalline phase. The binding of QDs-Hb occurs through corona formation to the ground sate complex formation. The life time of the heme pocket binding and reorganization were found to be t1 = 43 min and t2 = 642 min, respectively. The emission quenching of the Hb has been indicated large energy transfer between CdS QDs and Hb with tertiary deformation of Hb. The binding thermodynamics showed highly exothermic nature. The ultrafast decay during corona formation was studied from TCSPC. The results showed that the energy transfer efficiency increases with the increase of the QDs concentration and maximum ≈71.5 % energy transfer occurs and average ultrafast lifetime varies from 5.45 ns to1.51 ns. The deformation and unfolding of the secondary structure of Hb with changes of the α-helix (≈74 % to ≈51.07 %) and ß-sheets (≈8.63 % to ≈10.25 %) have been observed from circular dichroism spectrum. The SAXS spectrum showed that the radius of gyration of CdS QDs-Hb bioconjugate increased (up to 23 ± 0.45 nm) with the increase of the concentration of QDs compare with pure Hb (11 ± 0.23 nm) and Hb becoming more unfolded.
Asunto(s)
Compuestos de Cadmio , Transferencia de Energía , Hemoglobinas , Desplegamiento Proteico , Puntos Cuánticos , Sulfuros , Puntos Cuánticos/química , Humanos , Compuestos de Cadmio/química , Sulfuros/química , Sulfuros/metabolismo , Hemoglobinas/química , Hemoglobinas/metabolismo , Unión Proteica , Termodinámica , Espectrometría de Fluorescencia , Dicroismo CircularRESUMEN
In present work, blue carbon dots (b-CDs) were derived from ammonium citrate and guanidine hydrochloride, and red carbon dots (r-CDs) were stemmed from malonate, ethylenediamine and mesotetra (4-carboxyphenyl) porphin based on facile hydrothermal method. Eco-friendly ratiometric fluorescence probe was innovatively constructed to effectively measure Hg2+ utilizing b-CDs and r-CDs. The developed probe displayed two typical emission peaks at 450 nm from b-CDs and 650 nm from r-CDs under the excitation at 360 nm. Mercury ion has strong quenching effect on the fluorescence intensity at 450 nm due to the electron transfer process and the fluorescence change at 450 nm was used as the response signal, whereas the fluorescence intensity at 650 nm kept unchangeable which resulted from the chemical inertness between Hg2+ and r-CDs, serving as the reference signal in the sensing system. Under optimal circumstances, this probe exhibited an excellent linearity between the fluorescence response values of ΔF450/F650 and Hg2+ concentrations over range of 0.01-10 µmol/L, and the limit of detection was down to 5.3 nmol/L. Furthermore, this probe was successfully employed for sensing Hg2+ in practical environmental water samples with satisfied recoveries of 98.5%-105.0%. The constructed ratiometric fluorescent probe provided a rapid, environmental-friendly, reliable, and efficient platform for measuring trace Hg2+ in environmental field.
Asunto(s)
Carbono , Colorantes Fluorescentes , Mercurio , Puntos Cuánticos , Contaminantes Químicos del Agua , Mercurio/análisis , Carbono/química , Colorantes Fluorescentes/química , Contaminantes Químicos del Agua/análisis , Puntos Cuánticos/química , Monitoreo del Ambiente/métodos , Espectrometría de Fluorescencia/métodos , Límite de Detección , FluorescenciaRESUMEN
BACKGROUND: Curcumin has been used in traditional medicine because of its pharmacological activity, including antioxidant, antibacterial, anticancer, and anticarcinogenic properties. Therefore, sensitive and selective monitoring of curcumin is highly demand for practical application. RESULTS: In this study, we describe the construction of a fluorescence method for curcumin assay based on nitrogen-doped MoS2 quantum dots (N-MoS2 QDs). The N-MoS2 QDs are constructed by a solvothermal method using sodium molybdate and Cys as precursors. With the addition of curcumin, the bright blue fluorescence of N-MoS2 QDs is quenched by the inner filter effect (IFE). The QDs emitted bright blue fluorescence and could be quenched by the addition of curcumin via IFE. The dynamic range is the range of 0.1-10 µM for curcumin detection, with a detection limit of 59 nM. N-MoS2 QDs were applied for curcumin assay in real samples with good recovery. In addition, the N-MoS2 QDs exhibited relative low cytotoxicity and could be applied for fluorescence-based imaging in biological samples. SIGNIFICANCE: Our study indicates that the sensor possesses good selectivity to monitor curcumin in water samples, human urine samples, ginger powder samples, mustard samples, and curry samples with satisfactory recoveries. The N-MoS2 QDs possess less cytotoxicity with excellent biocompatibility and were applied for in vitro cell imaging.
Asunto(s)
Curcumina , Disulfuros , Colorantes Fluorescentes , Molibdeno , Nitrógeno , Puntos Cuánticos , Curcumina/química , Curcumina/farmacología , Puntos Cuánticos/química , Molibdeno/química , Humanos , Disulfuros/química , Colorantes Fluorescentes/química , Colorantes Fluorescentes/síntesis química , Nitrógeno/química , Imagen Óptica , Límite de Detección , Espectrometría de Fluorescencia , Supervivencia Celular/efectos de los fármacosRESUMEN
The capped CdS-ZnS quantum dots (QDs) were synthesized with various thiol capping agents of glycolic acid (TGA), mercaptosuccinic acid (MSA), and L-cysteine (LCY) and used as fluorescence probe for determination of Cu (II) ions. The method of two-level three-factor full-factorial experiment design was used to achieve the best optical fluorescence emission. Results revealed that Cu (II) ions can effectively quench the emission of QDs, and the fluorescence intensity is linearly decreased with increasing Cu (II) ion concentration. The limit of detection for CdS-ZnS@ QDs capped with TGA, MSA, and LCY was obtained at 1.15 × 10-7, 1.32 × 10-7, and 2.19 × 10-7 mol L-1, respectively, with linear dynamic range of 3.13 × 10-6 to 1.41 × 10-4 mol L-1. Luminescence quantum yields of CdS-ZnS@LCY, CdS-ZnS@MSA, and CdS-ZnS@TGA were obtained at 4.17, 1.92, and 2.47, respectively. Results indicated that no significant quenching occurred in the presence of the other metal ions. The binding constant (Kb) of capped CdS-ZnS@ QDs with Cu2+ and the other metal ions was also investigated and discussed. The Kb value for Cu2+ was obtained considerably more than that the other ions. This work presents a new and sensitive method for determination of Cu2+ ion.
Asunto(s)
Compuestos de Cadmio , Cobre , Colorantes Fluorescentes , Puntos Cuánticos , Compuestos de Sulfhidrilo , Sulfuros , Propiedades de Superficie , Compuestos de Zinc , Puntos Cuánticos/química , Cobre/química , Cobre/análisis , Sulfuros/química , Compuestos de Zinc/química , Compuestos de Cadmio/química , Compuestos de Sulfhidrilo/química , Compuestos de Sulfhidrilo/análisis , Colorantes Fluorescentes/química , Colorantes Fluorescentes/síntesis química , Espectrometría de Fluorescencia , Fluorescencia , Iones/química , Iones/análisisRESUMEN
The microenvironment of wound healing is susceptible to bacterial infection, chronic inflammation, oxidative stress, and inadequate angiogenesis, requiring the development of innovative wound dressings with antibacterial, anti-inflammatory, antioxidant, and angiogenic capabilities. This research crafted a new multifunctional bacterial cellulose composite membrane infused with copper-doped carbon dots (BC/Cu(II)-RCDs). Findings validated the successful loading of copper-doped carbon dots onto the BC membrane via hydrogen bonding interactions. Compared to the pure BC membrane, the BC/Cu(II)-RCDs composite membrane exhibited significantly enhanced hydrophilicity, tensile properties, and thermal stability. Diverse in vitro assays demonstrated excellent biocompatibility and antibacterial activity of BC/Cu(II)-RCDs composite membranes, alongside their ability to expedite the inflammatory phase and stimulate angiogenesis. In vivo trials corroborated the membrane's ability to foster epithelial regeneration, collagen deposition, and tissue regrowth in full-thickness skin wounds in rats while also curbing inflammation in infected full-thickness skin wounds. More importantly, the treatment of the BC/Cu(II)-RCDs composite membrane may result in the activation of VEGF and MAPK signaling proteins, which are key players in cell migration, angiogenesis, and skin tissue development. In essence, the developed BC/Cu(II)-RCDs composite membrane shows promise for treating infected wounds and serves as a viable alternative material for medicinal bandages.
Asunto(s)
Antibacterianos , Carbono , Celulosa , Cobre , Cicatrización de Heridas , Cicatrización de Heridas/efectos de los fármacos , Cobre/química , Celulosa/química , Celulosa/farmacología , Animales , Antibacterianos/farmacología , Antibacterianos/química , Carbono/química , Ratas , Humanos , Masculino , Ratas Sprague-Dawley , Staphylococcus aureus/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Puntos Cuánticos/químicaRESUMEN
A highly water-soluble and fluorescent N,S-doped carbon dots/europium (N,S-CDs/Eu) was successfully synthesized via a secondary hydrothermal method. This involved surface modification of N,S-CDs derived from sunflower stem pith (SSP) with europium ions (Eu3+) doping. When excited within the range of 400-470 nm, N,S-CDs/Eu exhibited a stable and broad optimal emission wavelength ranging from 505 to 540 nm. Notably, the photoluminescence quantum yield (PLQY) of N,S-CDs/Eu is 31.4%, significantly higher than the 19.5% observed for N,S-CDs. Additionally, by dissolving N,S-CDs/Eu into polyvinyl alcohol (PVA), a uniform fluorescent anti-counterfeiting ink can be prepared. The N,S-CDs/Eu/TiO2 composite demonstrates excellent photocatalytic degradation ability towards the organic dye methylene blue (MB). N,S-CDs/Eu has potential in the field of fluorescent inks and photocatalysis due to its simple and efficient preparation and excellent properties.
Asunto(s)
Carbono , Europio , Helianthus , Tinta , Puntos Cuánticos , Europio/química , Carbono/química , Catálisis , Puntos Cuánticos/química , Helianthus/química , Procesos Fotoquímicos , Colorantes Fluorescentes/química , Colorantes Fluorescentes/síntesis química , Azul de Metileno/química , FluorescenciaRESUMEN
Easy, economical, and swift detecting tools are very demanded for assaying various chemical species. The introduction of label-free paper-based read-out devices has significantly reached the demand of analytical science for target analytes assays. Herein, a facile, and disposable inexpensive paper-based sensing tool was fabricated for sensing As3+ ion using graphene quantum dots (GQDs) as a fluorescent reader. The CA-GQDs were synthesized using citric acid (CA) as a precursor via the pyrolysis method, further physisorbed on the cellulose substrate for sensing of As3+ via aggregation-based fluorescence "turn-off" mechanism. The linear range for quantitating As3+ ion is in the range of 0.05-50 µM with a detection limit of 10 nM. The practical application of the CA-GQDs-based analytical platform was verified by assaying As3+ ion in water samples. The CA-GQDs-embedded paper strip can be easily extended for assaying of As3+ ion, which meets the demand for monitoring of As3+ ion in real samples.
Asunto(s)
Celulosa , Grafito , Papel , Puntos Cuánticos , Grafito/química , Puntos Cuánticos/química , Celulosa/química , Colorantes Fluorescentes/química , Colorantes Fluorescentes/síntesis química , Espectrometría de Fluorescencia , Iones/análisis , Iones/química , Límite de Detección , FluorescenciaRESUMEN
Tannic acid (TA)-derived carbon dots (TACDs) were synthesized for the first time via a solvothermal method using TA as one of the raw materials, which may effectively inhibit amyloid fibril aggregation and disaggregate mature fibril. The fluorescent property of TACDs were modulated by adjusting the ratio of TA to o-phenylenediamine (oPD), and TACDs fabricated with the precursor ratio as 1:1 showed the best fluorescent property. Circular dichroism spectra (CD) showed that the structure of ß-sheet decreased as the concentration of TACDs increased. The inhibition efficiency, as confirmed by thioflavin T (ThT) and transmission electron microscopy (TEM), is extraordinary at 98.16%, whereas disaggregation efficiency is noteworthy at 97.97%, and the disaggregated lysozyme fibrils did not reaggregate after 7 days. More critically, TACDs can also alleviate the cellular toxicity caused by Aß fibrils and improve cell viability. This work offers a new perspective on the design of scavengers for amyloid plaques.
Asunto(s)
Carbono , Agregado de Proteínas , Taninos , Taninos/química , Taninos/farmacología , Carbono/química , Humanos , Agregado de Proteínas/efectos de los fármacos , Muramidasa/química , Muramidasa/metabolismo , Supervivencia Celular/efectos de los fármacos , Puntos Cuánticos/química , Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/metabolismo , Amiloide/química , Amiloide/metabolismo , Fenilendiaminas/química , Fenilendiaminas/farmacología , Animales , PolifenolesRESUMEN
Based on novel phosphorus-doped carbon dots (PCDs), a simple, quick, and accurate fluorescence probe for sarecycline (SAR) determination has been created. The PCDs were prepared in just five minutes using green, straightforward one-step microwave pyrolysis. To create the PCD probe, sodium phosphate monobasic was utilized as a phosphorus dopant and citric acid as a carbon supply. The proposed synthesis method was energy efficient and yielded CDs with a narrow particle size distribution. Based on inner-filter effect mechanism, the generated PCDs were used as nano-probe for SAR determination. The fluorescence quenching intensity showed a strong linear relationship with SAR concentration in the 3-90-µM range with a detection limit of 0.88 µM. Because there is no surface alteration of the CDs or creation of a covalent bond between SAR and PCDs, the developed approach is quick, easy, inexpensive, and requires less time. The new probe's enhanced sensitivity, broad linear range, and acceptable selectivity made it suitable for SAR measurement in pharmaceutical formulations and spiked human plasma. Most importantly, the Green Analytical Procedure Index (GAPI) and Analytical GREEnness (AGREE) assessments showed that the suggested method was environmentally friendly.
Asunto(s)
Carbono , Fósforo , Puntos Cuánticos , Carbono/química , Humanos , Fósforo/química , Puntos Cuánticos/química , Colorantes Fluorescentes/química , Tetraciclinas/análisis , Tetraciclinas/sangre , Espectrometría de Fluorescencia , Tamaño de la Partícula , Formas de Dosificación , Límite de DetecciónRESUMEN
Background: The formation of adhesion after tendon injury represents a major obstacle to tendon repair, and currently there is no effective anti-adhesion method in clinical practice. Oxidative stress, inflammation, and fibrosis can occur in tendon injury and these factors can lead to tendon adhesion. Antioxidant carbon dots and ursolic acid (UA) both possess antioxidant and anti-inflammatory properties. In this experiment, we have for the first time created RCDs/UA@Lipo-HAMA using red fluorescent carbon dots and UA co-encapsulated liposomes composite hyaluronic acid methacryloyl hydrogel. We found that RCDs/UA@Lipo-HAMA could better attenuate adhesion formation and enhance tendon healing in tendon injury. Materials and Methods: RCDs/UA@Lipo-HAMA were prepared and characterized. In vitro experiments on cellular oxidative stress and fibrosis were performed. Reactive oxygen species (ROS), and immunofluorescent staining of collagens type I (COL I), collagens type III (COL III), and α-smooth muscle actin (α-SMA) were used to evaluate anti-oxidative and anti-fibrotic abilities. In vivo models of Achilles tendon injury repair (ATI) and flexor digitorum profundus tendon injury repair (FDPI) were established. The major organs and blood biochemical indicators of rats were tested to determine the toxicity of RCDs/UA@Lipo-HAMA. Biomechanical testing, motor function analysis, immunofluorescence, and immunohistochemical staining were performed to assess the tendon adhesion and repair after tendon injury. Results: In vitro, the RCDs/UA@Lipo group scavenged excessive ROS, stabilized the mitochondrial membrane potential (ΔΨm), and reduced the expression of COL I, COL III, and α-SMA. In vivo, assessment results showed that the RCDs/UA@Lipo-HAMA group improved collagen arrangement and biomechanical properties, reduced tendon adhesion, and promoted motor function after tendon injury. Additionally, the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) in the RCDs/UA@Lipo-HAMA group increased; the levels of cluster of differentiation 68 (CD68), inducible Nitric Oxide Synthase (iNOS), COL III, α-SMA, Vimentin, and matrix metallopeptidase 2 (MMP2) decreased. Conclusion: In this study, the RCDs/UA@Lipo-HAMA alleviated tendon adhesion formation and enhanced tendon healing by attenuating oxidative stress, inflammation, and fibrosis. This study provided a novel therapeutic approach for the clinical treatment of tendon injury.
Asunto(s)
Antioxidantes , Carbono , Hidrogeles , Liposomas , Ratas Sprague-Dawley , Traumatismos de los Tendones , Triterpenos , Ácido Ursólico , Animales , Triterpenos/farmacología , Triterpenos/química , Antioxidantes/farmacología , Antioxidantes/química , Liposomas/química , Traumatismos de los Tendones/tratamiento farmacológico , Adherencias Tisulares/tratamiento farmacológico , Carbono/química , Carbono/farmacología , Hidrogeles/química , Hidrogeles/farmacología , Ratas , Estrés Oxidativo/efectos de los fármacos , Masculino , Cicatrización de Heridas/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Puntos Cuánticos/química , Ácido Hialurónico/química , Ácido Hialurónico/farmacología , Tendón Calcáneo/efectos de los fármacos , Tendón Calcáneo/lesionesRESUMEN
Depression is a debilitating mental illness that severely threatens millions of individuals and public health. Because of the multifactorial etiologies, there is currently no cure for depression; thus, it is urgently imperative to find alternative antidepressants and strategies. Growing evidence underscores the prominent role of oxidative stress as key pathological hallmarks of depression, making oxidative stress a potential therapeutic target. In this study, we report a N-doped carbon dot nanozyme (CDzyme) with excellent antioxidant capacity for treating depression by remodeling redox homeostasis and gut microbiota. The CDzymes prepared via microwave-assisted fast polymerization of histidine and glucose exhibit superior biocompatibility. Benefiting from the unique structure, CDzymes can provide abundant electrons, hydrogen atoms, and protons for reducing reactions, as well as catalytic sites to mimic redox enzymes. These mechanisms collaborating endow CDzymes with broad-spectrum antioxidant capacity to scavenge reactive oxygen and nitrogen species (â¢OH, O2-â¢, H2O2, ONOO-), and oxygen/nitrogen centered free radicals. A depression animal model was established by chronic unpredictable mild stress (CUMS) to evaluate the therapeutic efficacy of CDzymes from the behavioral, physiological, and biochemical index and intestinal flora assessments. CDzymes can remarkably improve depression-like behaviors and key neurotransmitters produced in hippocampus tissues and restore the gut microbiota compositions and the amino acid metabolic functions, proving the potential in treating depression through the intestinal-brain axis system. This study will facilitate the development of intestinal flora dysbiosis nanomedicines and treatment strategies for depression and other oxidative stress related multifactorial diseases.
Asunto(s)
Antioxidantes , Carbono , Depresión , Microbioma Gastrointestinal , Animales , Microbioma Gastrointestinal/efectos de los fármacos , Carbono/química , Carbono/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Depresión/tratamiento farmacológico , Ratones , Estrés Oxidativo/efectos de los fármacos , Estrés Psicológico/tratamiento farmacológico , Masculino , Puntos Cuánticos/química , Antidepresivos/farmacología , Antidepresivos/químicaRESUMEN
The present study explores the synthesis and bio-safety evaluation of gadolinium-doped carbon quantum dots (GCQDs) as a potential dual-contrast agent for diagnostic imaging. GCQDs exhibit both fluorescent and magnetic properties, making them suitable for UV-Vis and magnetic resonance imaging (MRI). The synthesis of GCQDs was achieved via hydrothermal treatment, incorporating gadolinium into the carbon quantum dot matrix. The magnetic properties of GCQDs were analyzed, showing significantly enhanced values compared to gadobutrol, a common MRI contrast agent. However, synthesis constraints limit the gadolinium content achievable in nanodots. To assess the safety of GCQDs, their effects on the embryonic development of zebrafish (Danio rerio) were examined. Various concentrations of GCQDs were tested, observing mortality rates, hatchability, malformations, heartbeats, spontaneous movement, and GCQDs uptake. Dialysis studies indicated that gadolinium ions are incorporated into the internal structure of the carbon nanodots. Zebrafish toxicity tests revealed that while survival rates were comparable to control groups, hatchability decreased significantly with higher gadolinium concentrations in GCQDs. Fluorescence microscopy showed no statistical differences in the fluorescence intensity between groups. These findings suggest that GCQDs could serve as an effective dual-contrast agent, combining the optical imaging capabilities of CQDs with the enhanced MRI contrast provided by gadolinium. This study underscores the need for further research on the synthesis methods and biological interactions of GCQDs to ensure their safety and efficacy in medical applications.
Asunto(s)
Carbono , Medios de Contraste , Gadolinio , Imagen por Resonancia Magnética , Puntos Cuánticos , Pez Cebra , Puntos Cuánticos/química , Puntos Cuánticos/toxicidad , Gadolinio/química , Medios de Contraste/química , Medios de Contraste/síntesis química , Animales , Pez Cebra/embriología , Carbono/química , Imagen por Resonancia Magnética/métodos , Diagnóstico por Imagen/métodosRESUMEN
Teicoplanin has been banned in the veterinary field due to the drug resistance of antibiotics. However, teicoplanin residue from the antibiotic abuse of humans and animals poses a threat to people's health. Therefore, it is necessary to develop an efficient way for the highly accurate and reliable detection of teicoplanin from humans, food, and water. In this study, novel imprinted quantum dots of teicoplanin were prepared based on boronate affinity-based precisely controlled surface imprinting. The imprinting factor (IF) for teicoplanin was evaluated and reached a high value of 6.51. The results showed excellent sensitivity and selectivity towards teicoplanin. The relative fluorescence intensity was inversely proportional to the concentration of teicoplanin, in the range of 1.0-17 µM. And its limit of detection (LOD) was obtained as 0.714 µM. The fluorescence quenching process was mainly controlled by a static quenching mechanism via the non-radiative electron-transfer process between QDs and the five-membered cyclic boronate esters. The recoveries for the spiked urine, milk, and water samples ranged from 95.33 to 104.17%, 91.83 to 97.33, and 94.22 to 106.67%, respectively.
Asunto(s)
Antibacterianos , Ácidos Borónicos , Puntos Cuánticos , Teicoplanina , Puntos Cuánticos/química , Humanos , Teicoplanina/química , Teicoplanina/análisis , Ácidos Borónicos/química , Antibacterianos/análisis , Antibacterianos/química , Espectrometría de Fluorescencia/métodos , Límite de Detección , Agua/química , Impresión Molecular/métodos , Ésteres/química , Ésteres/análisis , Transporte de Electrón , Contaminación de Alimentos/análisis , Análisis de los Alimentos/métodos , Animales , Técnicas Biosensibles/métodos , Leche/química , FluorescenciaRESUMEN
This study investigated the molecular mechanism behind the highly efficient performance of nitrogen-doped carbon dots (NCDs)-assisted microbial electrosynthesis systems (MESs). The impact of NCDs (C:N precursor = 1:0.5-1:3) on acetogens was examined in the biocathode. The highest electrocatalytic performance was observed with NCDs1:1. The maximum acetate production rate of 1.9 ± 0.1 mM d-1 was achieved in NCDs1:1-modified MESs, which was 26.7-216.7 % higher than other MESs (0.6-1.5 mM d-1). With NCDs1:1 modified, the biocathode exhibited a 129.3-186.8 % increase in the abundance of Sporomusa, and 38.5-104.6 % increase in cytochrome expression (cydAB, cybH). Transcriptome confirmed that cytochromes played a crucial role in the extracellular electron uptake (EEU) of NCDs1:1-modified Sporomusa. NCDs1:1 enhanced EEU efficiency, thereby increasing the two H+-pumping steps and accelerating microbial CO2 fixation. These results provide valuable insights into increasing CO2 fixation by maximizing EEU efficiency in acetogens.
Asunto(s)
Carbono , Nitrógeno , Carbono/farmacología , Acetatos/metabolismo , Electrones , Electrodos , Dióxido de Carbono/metabolismo , Fuentes de Energía Bioeléctrica , Puntos Cuánticos/química , Transporte de ElectrónRESUMEN
Kojic acid (KA) has gained significant attention due to its widespread use in the food and cosmetics industries. However, concerns about its potential carcinogenic effects have heightened the need for sensitive detection methods. This study introduces a fluorescence-based optical sensor for the quantification of KA in food samples, utilizing fluorescent carbon dots (CDs) synthesized from pomegranate peel via a hydrothermal method. The Stern-Volmer plot demonstrated a linear response for KA in the range of 120 to 1200 µM, with a Pearson correlation coefficient (r) of 0.9999 and. The sensor exhibited a detection limit of 30 ± 0.04 µM and a limit of quantification (LOQ) of 90 ± 0.14 µM. Application of the developed method to soy sauce and vinegar samples yielded accurate KA determinations, with recoveries of 103.11 ± 0.96% and 104.45 ± 2.15%, respectively. These findings highlight the potential of the proposed sensor for practical applications in food quality and safety assessment, offering valuable insights into the presence of KA in food products.
Asunto(s)
Carbono , Análisis de los Alimentos , Granada (Fruta) , Pironas , Puntos Cuánticos , Granada (Fruta)/química , Pironas/análisis , Pironas/química , Carbono/química , Puntos Cuánticos/química , Análisis de los Alimentos/métodos , Límite de Detección , Colorantes Fluorescentes/química , Contaminación de Alimentos/análisis , Espectrometría de Fluorescencia/métodosRESUMEN
Chiral amino acids (AAs) are essential in metabolism and understanding physiological processes, and they could be used as biomarkers for the diagnosis of different diseases. In this study, chiral Cdots@Van were prepared by postmodifying an achiral Cdots core with vancomycin for recognizing and determining the enantiomeric excess (ee) of tyrosine (Tyr) enantiomers. The fluorescence response of Cdots@Van is based on an "on-off" strategy, with different quenching percentages for d- and l-tyrosine. Interestingly, the circular dichroism (CD) spectrum of Cdots@Van responded to only one form of Tyr enantiomer, specifically d-Tyr, and remained nearly unchanged upon the addition of l-Tyr. Quantum mechanical (QM) calculations were in excellent agreement with the experimental results, confirming the stronger binding affinity of Cdots@Van for d-Tyr compared to l-Tyr. We further investigated the chiral recognition ability of the interconnected vancomycin particles, which was synthesized using the EDC/NHS coupling reaction between vancomycin molecules without a Cdots core. Surprisingly, unlike free vancomycin molecules, interconnected vancomycin displayed an enantiomeric recognition ability by CD spectroscopy, similar to what was observed for Cdots@Van. Crucially, this chiral probe has been successfully utilized for cell imaging applications.
Asunto(s)
Dicroismo Circular , Tirosina , Vancomicina , Tirosina/química , Vancomicina/química , Humanos , Estereoisomerismo , Colorantes Fluorescentes/química , Puntos Cuánticos/química , Espectrometría de Fluorescencia , Imagen ÓpticaRESUMEN
BACKGROUND: Carbon quantum dots (CQDs) have gained much interest recently for being efficient probes. Their cost-effectiveness, eco-friendliness, and unique photocatalytic activities made them distinctive alternatives to other luminescent approaches like fluorescent dyes and luminous derivatization. Meanwhile, delafloxacin (DLF) is a recently approved antibacterial medicine. DLF has been authorized for the treatment of soft-tissue and skin infections as well as pneumonia. Therefore, new eco-friendly, cost-effective, and sensitive tools are needed its estimation in different matrices. RESULTS: In the proposed study, green copper and nitrogen carbon dots (Cu-N@CDs) were synthesized from a green source (plum juice with copper sulphate). Cu-N@CQDs were then characterized using multiple tools including X-ray photon spectroscopy (XPS), FTIR and UV-VIS spectroscopy, Zeta potential measurements, High-resolution transmission electron microscopy (HRTEM), and fluorescence spectroscopy. After gradually adding DLF, the developed quantum dots' fluorescence was significantly enhanced within the working range of 0.5-100.0 ng mL-1. The limits of detection and quantification were 0.08 and 0.27 ng mL-1, respectively. The accuracy of the proposed method ranged from 96.00 to 99.12 % in recovery%, when recovered from milk and plasma samples. SIGNIFICANCE: Cu-N@CDs were utilized and validated for selectively determining DLF in several matrices including pharmaceutical forms, human plasma and in milk samples using spectrofluorimetric technique. The bio-analytical method is simple and could be used in content uniformity testing as well as in therapeutic drug monitoring in human plasma.
Asunto(s)
Carbono , Cobre , Fluoroquinolonas , Nitrógeno , Puntos Cuánticos , Puntos Cuánticos/química , Nitrógeno/química , Cobre/química , Carbono/química , Fluoroquinolonas/análisis , Fluoroquinolonas/sangre , Fluoroquinolonas/química , Humanos , Animales , Fluorometría/métodos , Límite de Detección , Espectrometría de Fluorescencia , Leche/química , Antibacterianos/sangre , Antibacterianos/análisis , Antibacterianos/químicaRESUMEN
Carbon dots (CDs) have garnered extensive interest in basic physical chemistry as well as in biomedical applications due to their low cost, good biocompatibility, and great aqueous solubility. However, the synthesis of multi-functional carbon dots has always been a challenge for researchers. Here, we synthesized novel CDs with a high quantum yield of 28.2% through the straightforward hydrothermal method using Diaminomaleonitrile and Boc-D-2, 3-diaminopropionic acid. The size, chemical functional group, and photophysical properties of the CDs were characterized by TEM, FTIR, XPS, UV, and fluorescence. It was demonstrated in this study that the prepared CDs have a high quantum yield, excellent photostability, and low cytotoxicity. Regarding the highly water-soluble property of CDs, they were proven to possess selective and sensitive behavior against Cu2+ ions (linear range = 0-9 µM and limit of detection = 1.34 µM). Moreover, the CDs were utilized in fluorescent ink in anti-counterfeiting measures. Because of their low cytotoxicity and good biocompatibility, the CDs were also successfully utilized in cell imaging. Therefore, the as-prepared CDs have great potential in fluorescence sensing, anti-counterfeiting, and bioimaging.