Boron-doped Carbon Dots Research Articles

Boron-doped carbon dots with time-resolved room temperature phosphorescence for detection of ciprofloxacin hydrochloride and information encryption applications.

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.

Visible‐Light Manipulated Reversible and Ultralong Phosphorescence of Carbon Dots Through Dynamic Cross‐Linking

AbstractDynamic 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.

Design of new boron-doped carbon dots for nano-level assay of nebivolol in human plasma and commercial products; Application to greenness assessments

Recently, nanomaterials have attracted a lot of attention due to their potential as effective fluorescent nano-sensor probes. They were distinguishing substitutes for other luminescent techniques, such as fluorescent dyes and luminous derivatization, because of their affordability, environmental friendliness, and special photocatalytic properties. In the suggested work, a straightforward method was used to create boron and nitrogen carbon dots (B@CDs) with a good quantum yield value of 31.15 % utilizing boric acid and di-sodium EDTA. For the purpose of characterizing QDs, a variety of instruments were employed, such as transmission electron microscopy, fluorescence spectroscopy, X-ray FTIR, and UV–VIS spectroscopy. Nebivolol (NEB) is a cardiovascular medication used globally to treat congestive heart failure and hypertension, is in the meantime. For this reason, a brand-new, environmentally friendly analytical technique was created to determine the amount of human plasma, uniformity test, and commercial nebivolol (NEB) tablets. After gradually adding NEB, the response of B@CQDs was enhanced at 438 nm (excitation at 371 nm). The calibration graph ranged between 20 and 500 ng mL−1 with a quantification limit (LOQ) of 2.50 ng mL−1 and a detection limit (LOD) of 0.82 ng mL−1.

High enrichment and sensitive measurement of oxytetracycline in tea drinks by thermosensitive magnetic molecular imprinting based magnetic solid phase extraction coupled with boron doped carbon dots

As a typical kind of new pollutants, there are still some challenges in the rapid detection of antibiotics. In this work, a sensitive fluorescent probe based on boron-doped carbon dots (B-CDs) in combination with thermo-responsive magnetic molecularly imprinted polymers (T-MMIPs) was constructed for the detection of oxytetracycline (OTC) in tea drinks. T-MMIPs were designed, fabricated and employed to enrich OTC at trace level from tea drinks, and B-CDs were utilized as the fluorescent probe to detect the concentration of OTC. The proposed method exhibited good linear relationship with OTC concentration from 0.2 to 60 μg L−1 and the limit of detection was 0.1 μg L−1. The established method has been successfully validated with tea beverages. Present work was the first attempt application of T-MMIPs in combination with CDs in detection of OTC, and demonstrated that the proposed method endowed the detection of OTC with high selectivity, sensitivity, reliability and wide application prospect, meanwhile offered a new strategy for the method establishment of rapid and sensitive detection of trace antibiotics in food and other matrices.

Strategic Assessment of Boron-Enriched Carbon Dots/Naproxen: Diagnostic, Toxicity, and In Vivo Therapeutic Evaluation.

Cancer is a significant global public health concern, ranking as the leading cause of mortality worldwide. This study thoroughly explores boron-doped carbon dots (B-CDs) through a simple/rapid microwave-assisted approach and their versatile applications in cancer therapy. The result was highly uniform particles with an average diameter of approximately 4 nm. B-CDs exhibited notable properties, including strong fluorescence with a quantum yield of 33%. Colloid stability tests revealed their robustness within a pH range of 6-12, NaCl concentrations up to 0.5 M, and temperatures ranging from 30 to 60 °C. The study also delved into the kinetics of naproxen release from B-CDs as a drug delivery system. The loading efficacy of naproxen exceeded 55.56%. Under varying pH conditions, the release of naproxen from B-CDs conformed to the Peppas-Sahlin model, demonstrating the potential of Naproxen-loaded CDs for cancer drug delivery. In vitro cytotoxicity assessments, conducted using the CCK-8 Assay and flow cytometry, consistently indicated low toxicity with average cell viability exceeding 80%. An in vivo toxicity test on female mice administered 20 mg/kg of B-CDs for 31 days revealed reversible histological changes in the liver and kidneys, while the pancreas remained unaffected. Importantly, B-CDs did not impact the mice's physical behavior, body weight, or survival. In vivo experiments targeting benzo(a)pyrene-induced fibrosarcoma demonstrated the efficacy of B-CDs as naproxen carriers in the treatment of cancer. This in vivo study provides a thorough comprehension of B-CDs synthesis and toxicity and their potential applications in cancer therapy and drug delivery systems.

Double Emissions in Boron-Doped Carbon Dots for Anticounterfeiting Applications

Double Emissions in Boron-Doped Carbon Dots for Anticounterfeiting Applications

Green synthesis of boron-doped carbon dots from Chinese herbal residues for Fe3+ sensing, anti-counterfeiting, and photodegradation applications

Carbon dots (CDs), especially from biomass doped with heteroatoms, have drawn increasing attention owing to their versatility in potential applications. In this work, boron-doped CDs derived from Chinese herbal residues (B@HRCDs) were fabricated through a simple, green, one-step solvothermal method, resulting in B@HRCDs with a uniform size of 2.8 nm. The synthesized B@HRCDs were characterized using Fourier transform infrared spectroscopy, UV–visible spectroscopy, Transmission electron microscopy, X-ray photoelectron spectroscopy, and Fluorescence techniques. As prepared, the B@HRCDs demonstrated a bright fluorescence with a quantum yield of 4.0% and displayed exceptional selectivity towards Fe3+. In vitro experiments, they did not exhibit cytotoxicity against BV2 cells. The synthesized B@HRCDs were used as a sensitive nanoprobe for the detection of free Fe3+ in the range of 0–80 μM with a minimum limit of detection (LOD) of 1.08 μM. Based on their biocompatibility and negligible cytotoxicity, B@HRCDs were also shown to be useful for intracellular Fe3+ detection applications. When fluorescent ink was applied to bond paper, the patterns were clearly visible under UV light, indicating that B@HRCDs can be used for message encryption. Finally, it was further shown that the degradation rate of indigo carmine after 5 h of sunlight irradiation was 91% in the presence of B@HRCDs and decreased to 61% after 5 cycles, which indicates that the B@HRCDs have favorable photocatalytic activity and photostability. It is thus believed that this strategy achieves the reuse of herbal residues and proposes a low-cost, green method for the synthesis of CDs with Fe3+ sensing, anti-counterfeiting, and photodegradation functions.

Synthesis of Photoluminescent Carbon Dots Using Hibiscus Tea Waste and Heteroatom Doping for Multi-Metal Ion Sensing: Applications in Cell imaging and Environmental Samples

Novel photoluminescent carbon dots (CDs) were synthesized through a facile hydrothermal method using Hibiscus tea extract as a natural carbon source and boric acid as a boron source. The optical and physicochemical properties of the as-synthesized nitrogen- and boron-doped CDs (NB-CDs) were characterized using UV–Visible (UV–Vis), photoluminescence (PL) spectroscopy, Fourier-transform infrared (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The as-synthesized NB-CDs showed spherical morphology of approximately 6.2 ± 0.5 nm with quantum yield (9.2%), high aqueous solubility, strong photo-stability, and excitation-dependent PL behavior. The obtained NB-CDs exhibited high stability over a wide pH range and high ionic strength. Additionally, NB-CDs exhibited PL enhancement response with excellent sensitivity toward multi-metal ions, including Ag+, Cd2+, and Cr3+ ions, with very low detection limits of 44.5, 164.4, and 54.6 nM, respectively, with a wide concentration range of 0–10 μM. Upon testing the cytotoxicity of the NB-CDs at a concentration of 20 μg/mL for 24 h, we found no obvious inhibition of cell viability. Therefore, the proposed sensor method can be successfully applied to detect Ag+, Cd2+, and Cr3+ ions in cell imaging as well as in real water environmental samples.

Regulating the spin density of CoIIIusing boron-doped carbon dots for enhanced electrocatalytic nitrate reduction

Using B-doped carbon dots loading to change the electron spin density of magnetic Co3O4results in excellent activity in the electrocatalytic nitrate reduction reaction.

A sequential dual-lock strategy for generation of room-temperature phosphorescence of boron doped carbon dots for dynamic anti-counterfeiting

Stimuli-responsive materials with dynamically switched room-temperature phosphorescence (RTP) aroused great interest. However, the dynamic control of RTP with a color-tunable persistent afterglow by external stimuli is still challenging. Herein, an appealing strategy for constructing dynamic hydrogen-bond networks based on boron-doped carbon quantum dots (BCQDs) was proposed to generate sequence-dependent stimuli-responsive RTP. The BCQDs exhibited bright RTP in paper matrix after successive stimulation by water and heat, demonstrating a fascinating regulation based on an AND logic gate. The RTP generated experienced a reversible switching without attenuation fatigue when BCQDs were heated and exposed to air. The switching of hydrogen-bond network from that among BCQDs to that between BCQDs and paper could facilitate the population of triplet-state BCQDs. The RTP can last a long timie of 10 s after the ceasation of excitation light source. Furthermore, the AND logic gate stimuli-responsive RTP with different colors in papers were obtainded for the first time after blending with various non-RTP dyes. The BCQDs with controllable and on-demand afterglow were further applied for advanced multi-level information encryption and anti-counterfeiting materials. The finding provided assistance to understand the origin and mechanism of the stimuli-responsive RTP of smart materials and offered opportunities for developing multiple continuous stimuli-responsive intelligent RTP materials.

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.

Exclusive nitrate to ammonia conversion via boron-doped carbon dots induced surface Lewis acid sites

Electrocatalytic nitrate reduction represents a very promising route for ammonia synthesis under ambient conditions. However, for most nitrate-to-ammonia electrocatalysts developed to date, the Faradaic efficiency (FE) to ammonia is modest due to the competitive hydrogen evolution reaction (HER). Here, we report that the decoration of vertically aligned NiCo2O4 pillars with boron-doped carbon dots (BCDs) enables electrocatalytic nitrate reduction to ammonia with ∼100% FE. A BCDs/NiCo2O4/carbon cloth cathode delivers a NH3 production rate of 173.9 μmol h−1 cm−2 at −0.55 V versus reversible hydrogen electrode (RHE). This state-of-the-art performance is linked to the BCDs, which provide an abundance of Lewis acid sites on the electrocatalyst surface for the adsorption of nitrate ions (simultaneously suppressing the competitive HER). This work reveals that highly selective NH3 electrosynthesis can be achieved under ambient conditions by regulating the surface acidity/basicity properties of metal-oxide-based catalysts, paving the way toward more sustainable NH3-production technologies.

Spectrofluorimetric Method for Monitoring Methotrexate in Patients' Plasma Samples and Cell Lysates Using Highly Fluorescent Carbon Dots.

For the first time, nitrogen, sulfur, phosphorus, and boron-doped carbon dots (N, S, P, B-codoped CDs) were synthesized through a hydrothermal reaction. The produced CDs were utilized to develop an optical sensor to determine methotrexate (MTX) in cell lysates and patients’ plasma samples. Basically, in the presence of MTX, the fluorescence emission of the CD-based probe was quenched. Under optimum conditions, a good proportional relationship was obtained between the quenched fluorescence signal and MTX concentrations from 74.9 ng/mL to 99.9 µg/mL with a limit of detection of 74.9 ng/mL. The developed nanoprobe provided a wide linear range and high accuracy and was successfully utilized in the routine therapeutic drug monitoring of MTX in plasma samples. The obtained results proposed the developed nanoprobe for the on-time and specific detection of MTX in blood samples. As another application, N, S, P, B-codoped CDs were utilized for bioimaging MCF-7 cancer cells and could be proposed as efficient bioimaging agents for tumor cells.

Long-Lived Color-Tunable Room-Temperature Phosphorescence of Boron-Doped Carbon Dots.

Carbon dots (CDs) with long-lived room-temperature phosphorescence (RTP) or long afterglow properties draw much attention. However, most room-temperature phosphorescent materials are metal containing, and the exploitation of long-lived color-tunable RTP materials faces great challenges. Here, we report metal-free boron-doped CDs (B-CDs) for room-temperature phosphorescence with tunable color and an ultralong lifetime. B-CDs were obtained by simply calcining a mixture of boric acid and 1,3,5-benzenetricarboxylic acid in the atmosphere. The as-prepared B-CDs were characterized through UV-vis spectroscopy, photoluminescence spectroscopy, and so forth. Under the excitation of 310 nm UV light, B-CDs show RTP that appears as blue with a phosphorescence lifetime of 1042 ms, and after switching the excited wavelength to 365 nm, the RTP appears as green with a phosphorescence lifetime of 590 ms. Due to the unique RTP properties, B-CDs display promising applications in anticounterfeiting and information encryption.

Exclusive Nitrate to Ammonia Conversion via Boron-Doped Carbon Dots Induced Surface Lewis Acid Sites

Exclusive Nitrate to Ammonia Conversion via Boron-Doped Carbon Dots Induced Surface Lewis Acid Sites

3D-printed bioactive scaffolds for bone regeneration bearing carbon dots for bioimaging purposes

Additive manufacturing, also known as 3D-printing, has been successfully employed to create novel bioactive scaffolds incorporating carbon dots for bioimaging purposes. Fused filament fabrication technique (FFF) was used to print a hybrid poly-lactic acid (PLA)-based filament bearing bioactive material, suited for hydroxyapatite (HAp) development, as well as carbon dots which by virtue of their strong luminescence could support an optical characterization of the composite, thus, its regenerative stages. This technique using FFF biodegradable PLA can be used to create the exact custom-made scaffold depending on the user needs (i.e. shape of a bone fracture), whereas the bioactive material (bioglass® 45S5) assists bone regeneration by HAp development. On the other hand, biocompatible red emissive boron-doped carbon dots could allow for monitoring of the procedure. Scaffolds were tested for their in vitro bioactivity by soaking in simulated body fluid (SBF) solution. In addition, in vitro cytotoxicity testing confirmed the low toxicity of the composite materials used for creating the scaffolds. Degradation of the PLA scaffold initiated immediately providing space for bone regeneration. HAp development was confirmed by scanning electron microscopy - energy dispersive X-ray spectroscopy (SEM/EDS) and infrared spectroscopy (IR). Ultraviolet visible and photoluminescence spectroscopies were used to evaluate the properties of the carbon dots as well as composite materials. Results indicate that this is a promising technique for confronting asymmetric or irregular-shaped bone fractures with simultaneous monitoring of the healing process through bioimaging.

In-vitro molecular interaction of boron doped carbon dots with human serum albumin

Carbon dots have drawn prodigious attention in biomedical and biological fields by virtue of its unique optical properties, but their effect on structure and behaviour of essential proteins have rarely been explored. In this study boron doped carbon dots (BCDs) which was synthesized by microwave treatment of citric acid, boric acid and urea, with maximum emission wavelength of 444 nm when excited upon long wavelength ultra-violet light. Synthesized BCDs were characterized by UV-Visible, FTIR, HRTEM and Fluorescence spectroscopy. Interaction between BCDs and human serum albumin (HSA) is carried out in physiological conditions. Stoichiometry of BCDs-HSA was found to be 1:1 and various thermodynamic parameters have also been calculated. The negative value of ΔG suggested that interaction between HSA and BCDs was spontaneous in nature.

High quantum yield boron-doped carbon dots: a ratiometric fluorescent probe for highly selective and sensitive detection of Mg2+ ions

Highly fluorescent boron-doped carbon dots were synthesized from catechol and naphthalene boronic acid by a solvothermal method. They showed violet luminescence under UV illumination and were explored for highly selective detection of Mg2+ ions, with an LOD of ~39 μM.

Comparison of the effects of synthesis methods of B, N, S, and P-doped carbon dots with high photoluminescence properties on HeLa tumor cells.

Although heteroatom doping is widely used to promote the optical properties of carbon dots for biological applications, the synthesis process still has problems such as multi-step process, complicating the setting of instrument along with uncontrolled products. In the present study, some elements such as boron, nitrogen, sulfur, and phosphor were intentionally doped into citric acid-based carbon dots by furnace- and microwave-assisted direct and simple carbonization processes. The process produced nanoparticles with an average diameter of 5–9 nm with heteroatoms (B, N, S, and P) placed on the core and surface of carbon dots. Among the doped carbon dots prepared, boron-doped carbon dots obtained by the microwave-assisted (B-CDs2) process showed the highest photoluminescence intensity with a quantum yield (QY) of about 32.96%. All obtained carbon dots exhibit good stability (at pH 6–12 and high ionic strength concentrations up to 0.5 M), whereas cytotoxicity analysis showed that all doped carbon dots are low-toxic with an average cell viability percentage above 80% up to 500 μg mL−1. It can be observed from the CLSM image of all doped carbon dots that the doping process not only increases the QY percentage, but also might accelerate the HeLa uptake on it and produce strong carbon dot emission at the cytoplasm of the cell. Thus, the proposed synthesis process is promising for high-potency bioimaging of HeLa cancer cells.

Engineering Surface Oxygen Functional Groups in Boron-Doped Carbon Dots for Improving Detection of Magnesium Ions Based on Chelation Enhanced Photoluminescence

Engineering Surface Oxygen Functional Groups in Boron-Doped Carbon Dots for Improving Detection of Magnesium Ions Based on Chelation Enhanced Photoluminescence