APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Yongyu Li,Jianjun Chen,Yaping Wang,Huiji Li,Jihong Yin,Mengyan Li,Ling Wang,Haijie Sun,Lingxia Chen
A one-step direct pyrolysis method without any post-treatment steps and a mass yield of up to 69% was realized for preparing N-doped carbon dots (NCDs). The NCDs exhibit excellent excitation-independent blue fluorescence with quantum yield (QY) of 65.5%, and their luminescence mechanism was explored based on optical properties and structural composition, which mainly originates from surface state photoluminescence (PL). The NCDs display highly selective and sensitive detection of Fe 3+ in tris-HCl buffer system, a good linear relationship between PL intensity ratios and Fe 3+ concentrations was obtained in concentration range of 0 to 400 μM with a low LOD of 0.703 μM. The formation of ferric hydroxide colloid is the main reason for the specific recognition of Fe 3+ by NCDs, and buffer solution plays a key role in the formation of ferric hydroxide colloid and selective detection of Fe 3+ . The sensing mechanism is a dynamic quenching electron transfer process in the action of hydrogen bonding and colloidal adsorption. Three real water samples were applied to evaluate actual application of NCDs probe, satisfactory recoveries (93.5%–105.6%) indicate that NCDs has great practical potential for detection of metal ions in environmental water assays.
研究领域:
材料科学
·
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Xue-Chun Yang,Yun-Ling Yang,Meng-Meng Xu,Shan-Shan Liang,Xiao-Long Pu,Jian-Feng Hu,Qian-Li Li,Jing-Tai Zhao,Zhi-Jun Zhang
Nitrogen-doped carbon dots (NCDs) synthesized by the low-temperature sintering method show electronegativity rich in −COO–, −CO–NH–, −NH–, and −OH. The structure, morphology, and fluorescence performance of NCDs were successively characterized by Fourier-transform, infrared, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, photoluminescence, ultraviolet (UV), and X-ray fluorescence analyses. On the one hand, NCDs can sensitively detect Pb2+ in water with a detection limit of 3 ppb through the dual response of fluorescence emission spectra and UV absorbance spectra. On the other hand, the negatively charged NCDs combine with various positively charged heavy metal ions (Pb2+, Cu2+, Ni2+, Co2+, and Cd2+) through charge attraction and coordination to form a hydrogel, thereby removing heavy metal ions from the water. Among them, the removal rate of Pb2+ by NCDs is as high as 94.8%. It is the first time that pure NCDs have been used to remove heavy metal ions quickly and easily in the form of a reversible hydrogel. A simple way is to achieve ultrasensitive detection and high-efficiency removal of heavy metal ions in water with unitary NCDs.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 12
·7574-7583
·
IF 4.036
Haiyan Qi,Demin Huang,Jing Jing,Maoxia Ran,Tao Jing,Ming Zhao,Chenqi Zhang,Xiaona Sun,Rokayya Sami,Nada Benajiba
Tetracycline (TC) is widely used as a veterinary drug, and its residue in livestock products could enter the human body and cause damage. In this study, we developed an eco-friendly approach that utilized pomelo peel as a carbon source to synthesize new water-soluble N-doped carbon dots (P-NCDs) with blue fluorescence, obtaining a high quantum yield of up to 76.47% and achieving the goal of turning waste into value. Our prepared P-NCDs can selectively recognized TC, and their fluorescence was quenched based on the IFE. P-NCDs could measure the TC concentration in the linear range of 0–100 μmol L−1 with a detection limit (LOD, S/N = 3) as low as 0.045 μmol L−1. Furthermore, we have successfully applied our P-NCDs to the detection of TC in milk samples with convincing results within 90 s. Overall, our newly synthesized fluorescent sensor, P-NCDs, demonstrated huge potential to become an alternative way to detect TC in a simple, efficient, sensitive way without using any special instruments.
研究领域:
环境科学
·
分析化学
·
生物医学工程
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 7
·2221-2227
·
IF 4.831
Lin Yanping,Yao Bixia,Huang Tingting,Zhang Shichao,Cao Xiaotong,Weng Wen
The authors report that nitrogen-doped carbon dots (N-CDs) represent a viable fluorescent probe for the determination of dissolved free chlorine. The N-CDs can be fairly easily prepared by a solvothermal method using citric acid, tartaric acid and ethanediamine as the precursors, display excitation/emission maxima of 360/460 nm, and have a quantum yield of 42.2 %. Free chlorine and ClO − quench fluorescence, and this was exploited to design a method for fluorometric determination of chlorine and hypochlorite. The probe has a short response time (< 1 min), excellent selectivity, high sensitivity, and a linear response range that extends from 0.1 to 27 μM. The limit of detection is as low as 29.7 nM. The method was applied to the determination of chlorine dissolved in tap water.
Fluorescent nitrogen-doped carbon dots (N-CQDs) displaying excitation/emission maxima of 360/460 nm were fabricated by a one-pot solvothermal method. The photoluminescence (PL) of the N-CQDs is quenched by free chlorine and ClO − , and this was exploited to design a method for fluorometric determination of chlorine and hypochlorite.
研究领域:
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Yuxin He,Hanting Wang,Yuting Yan,Xinhui Jiang,Hecun Zou,Zhengwei Zhang
Gefitinib, a highly significant antitumor drug, is now commonly employed in clinical settings as a first-line treatment for patients with advanced or metastatic non-small cell lung cancer, colon cancer, and breast cancer. Herein, a convenient, rapid, and accurate fluorescence method based on nitrogen-doped carbon dots (NCDs) was designed for ultrasensitive detection of gefitinib. The NCDs were easily synthesized through one-pot hydrothermal process using p -phenylenediamine and D-glutamic acid as the precursors. The sensing strategy relied on the fluorescence of NCDs at 345 nm, which was selectively reduced by gefitinib based on the inner filter effect (IFE). With a broad linear range of 0.025–30 μg/mL and a low limit of detection of 5.5 ng/mL, the probe was successfully applied to the detection of gefitinib in human serum samples, demonstrating strong practicality, affordability, and high accuracy. The proposed sensor is simple in design, fast in detection and cost-effective, and exhibits promising application in drug real-time analysis.
研究领域:
分析化学
·
药物分析
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 9
·4850-4856
·
IF 2.936
Qian Liu,Danting Li,Zhifeng Zhu,Shimeng Yu,Yan Zhang,Dabin Yu,Yang Jiang
To achieve competitive fluorescence carbon dots (CDs), studies on regulating fluorescence of CDs under controlled, comparable conditions are in great demand. Herein, by changing the functional groups and nitrogenous existence forms in the precursors, three efficient yellow-green emissive N-doped CDs which have the same fluorescence peak wavelength but different photoluminescence quantum yields were realized through a facile hydrothermal method. The as-prepared CDs exhibit not only excited-independent emissions but also similar surface states. The best-performing CDs among the three products exhibits photoluminescence quantum yields of up to 24.4% in water and 53.3% in ethanol, abundant surface functional groups and its high N-doping degree would be the reason for its excellent performances. By washing and reduction processes, the emission evolution of the CDs was studied linking the changes of surface states. The fluorescence can certainly be attributed to the surface of the carbon dots, and the surface states control the photoluminescence features. Serving as a yellow-green colour conversion layer, the best CDs in the three products was used to fabricate a white light-emitting diode. The white light-emitting diode shows an excellent colour rendering index up to 93.3, suggesting broad application prospects of the CDs in lighting and display fields.
研究领域:
材料科学
·
光学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Mingjun Cui,Siming Ren,Haichao Zhao,Liping Wang,Qunji Xue
Nitrogen doped carbon dots (NCDs) were synthesized and used for inhibiting the corrosion of Q235 carbon steel in hydrochloric acid (HCl) solution. Inhibition effectiveness in short- and long-term immersion was examined using electrochemical measurements, weight loss and surface analysis. Results revealed the inhibition efficiency was improved significantly after adding NCDs and strongly dependent on the concentration of NCDs. SVET results showed that the sample immersed in HCl solution with NCDs showed lower anodic current density mapping than that in blank HCl solution. According to the data extracted from the Langmuir adsorption, the absorption of NCDs involved both chemisorption and physisorption.
研究领域:
材料科学
·
腐蚀与防护
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2021
·Vol. 306
·期 10
·2100339
·
IF 4.367
Pei Liu,Chang Liu,Jiucun Chen,Bin Wang
Room-temperature phosphorescent (RTP) nitrogen-doped carbon dots (N-CDs) have attracted great interest but their efficiency is usually dependent on a solid matrix. Developing efficient matrix-free RTP CDs is still a great challenge. Here, a simple strategy is reported to synthesize efficient matrix free RTP N-CDs from citric acid (CA) and basic fuchsine (BF) via a single step hydrothermal process. The synthesized N-CDs show strong fluorescence in aqueous solution and the solid state, and the RTP lifetime is long-lived (51.9 ms at 298 K). The phosphorescence of the N-CDs is attributed to the formation of an internal hydrogen bonded network by the organic polymers on the surface of the N-CDs. This reduces the nonradiative transitions of the triplet excitons and mitigates oxygen quenching. The application of N-CDs as security inks is demonstrated.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2019
·
IF 3.261
Sai Kumar Tammina,Yaling Yang
Here in, the fluorescent nitrogen doped carbon dots (N-CDs) were synthesized by microwave digestion method using glucosamine and ethylenediamine as raw materials for carbon and amine sources. Correspondingly, N-CDs formation was further confirmed through XPS, XRD, TEM and FT-IR techniques. And the optical properties were further investigated using fluorescence and UV–vis spectrophotometry. The synthesized N-CDs were used to explore its sensing ability against 4-nitrophenol (4-NP), Cr(VI), and Ascorbic acid. The sensing strategies of 4-NP, Cr(VI) and Cr(VI)/ascorbic acid had showed the promising detection limits such as 0.05, 0.08 and 0.15 μM respectively. The investigation related to the fluorescence emission quenching of N-CDs against 4-NP and Cr(VI) were attributed to the inner filter effect (IFE), however in case of AA sensing strategy, it was due to the weakening on IFE, results in restoring of fluorescence emission from 0.25 to 175 μM concentration range of AA against N-CDs/Cr(VI) fluorescent probe. Whereas to assess the practicality of the detection strategy, real sample analysis was also performed, which showed the acceptable rates of recoveries and relative standard deviations towards N-CDs/Cr (VI) and N-CDs/Cr(VI)/AA probes. All in all, the reported N-CDs can be utilized in environmental and biological applications.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Rongzhen Ma,Lin Chang,Long D. Nghiem,Yuan Liu,Qilin Wang,Qianbin Zhao,Qingju Hao,Yimeng Gao,Hong Liu,Lei Zheng
Carbon dots have emerged as highly efficient and versatile fluorescent probes for detecting and quantifying Hg2+. This study reports a method to prepare nitrogen-doped carbon dots (N-CDs) via ligand-to-metal charge transfer fluorescent quenching for Hg2+ detection. Besides the excitation-independent emission feature, the synthesized N-CDs demonstrate a high selectivity of Hg2+ over 23 potentially interfering environmental ions. The structures of 2-hydroxy-N,N-dimethylbenzamide and amide functional groups are identified as the determinants of the relatively high quantum yield (53.33%). N-CDs also exhibit a linear relationship with Hg2+ concentration in the range of 0.007–120 μM, with a limit of detection of 7.1 nM. The produced N-CDs can be employed in a customized microfluidic real-time monitoring platform, demonstrating the robustness in receiving efficient fluorescence signals with a satisfactory limit of detection. The acceptable accuracy and recovery of Hg2+ detection in tap water and river water highlight the potential practical applications of the synthesized N-CDs. Results in this study can facilitate the development of a portable device for early warning of water pollution.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2016
·Vol. 40
·期 12
·10213-10218
·
IF 3.277
Guangming Li,Nan Lv,Wenzhi Bi,Jilin Zhang,Jiazuan Ni
To obtain nitrogen-doped carbon dots (N-CDs) for sensing Fe3+ under acidic conditions, robust and highly fluorescent N-CDs were prepared by one-pot hydrothermal treatment of dopamine and ethylenediamine. The N-CDs have a relatively uniform size of approximately 4.9 nm and good water dispersibility. The N-CDs exhibit strong visible fluorescence (ca. 497 nm) and high stability at low pH (i.e. 2–3). The FTIR spectra and the XPS analyses indicated that primary amines and distinctive catechol groups exist on the surface of the N-CDs. The FTIR spectra further prove that the catechol groups on their surfaces can be oxidized to the quinone species by Fe3+, contributing to fluorescence response to Fe3+. Thus, the N-CDs as fluorescence probes allowed the detection of Fe3+ under acidic conditions, which has been verified in this work.
研究领域:
化学
·
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2015
·
IF 4.513
Libo Li,Bin Yu,Xueping Zhang,Tianyan You
A novel Ru ( bpy ) 3 2 + -based electrochemiluminescence (ECL) sensing platform, using N-doped carbon nanodots (N–C dots) as co-reactant, was established for the sensitive and selective detection of bisphenol A (BPA). N–C dots not only could enhance the ECL signal, but also significantly improved the reproducibility and stability of Ru ( bpy ) 3 2 + ECL system. The developed ECL sensing system was sensitive to detect BPA based on its efficient quenching effect on Ru ( bpy ) 3 2 + / N − C dots. The N–C dots-enhanced ECL mechanism and BPA-quenched ECL mechanism were investigated. Under the optimum conditions, the inhibited ECL intensity was in good linear relationship versus the concentration of BPA in the range of 0.03–1.0 μM with the detection limit of 10 nM. The relative standard deviation (RSD) for 25 successive measurements with one sensor was 1.1% and for eight different sensors was 2.5%, respectively. The fabricated sensing platform was successfully applied for the detection of BPA in baby bottle and nipple, and relatively satisfactory recoveries were obtained.
研究领域:
分析化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）