FOOD CHEMISTRY
·
2023
·
IF 8.8
Xin-He Duan,Yi Li,Hong-Wei Li,Yuqing Wu
The quality control of Baijiu is necessary including ethanol content. In this work, red-emitted carbon quantum dots based on p -phenylenediamine (PPD-CQDs) were fabricated for accurate determination of ethanol in Baijiu. The good linear response of PPD-CQDs to ethanol–water solution (E-Ws; 20–80 vol%) offered the potential for ethanol determination in practice. However, further application of this procedure to Baijiu resulted in a certain deviation. After excluding interference from most of the ingredients involved, a simple pH correction on Baijiu made application of the process practicable. The red-emission of PPD-CQDs supported analysis of Baijiu with different flavors and ethanol monitoring. Therefore, a quick-response fluorescence method was established for Baijiu ethanol determination; this method can be applied to the many varieties of Chinese Baijiu available and also has potential for use in other alcoholic beverages.
研究领域:
食品科学
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分析化学
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DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2024
·
IF 8
Yan-nan Wang,Liyun Qin,Zhenyu Yuan,Jin Li,Fanli Meng
An optical fiber acetone gas sensor based on N-CQDs@In 2 O 3 porous ordered thin film is proposed. The probe adopts the hollow malposition structure (HMS) to excite the evanescent field on the surface of hollow-core fiber (HCF). N-CQDs@In 2 O 3 porous and ordered thin film was formed on the surface of optical fiber after calcining polystyrene (PS) microspheres at high temperature. The experimental results reveal the ultraviolet (UV) sensitization function for the proposed sensor at room temperature . The enhanced sensitivity is 7.1 pm/ppm, which is ∼5.9 times of the spiritual density of unsensitized sensor. In addition, the sensor has a limit of detection (LOD) of 500 ppb and excellent time response characteristics (response time 6.2 s and recovery time 7.1 s). The sensitization mechanism of N-CQDs to In 2 O 3 is explained by the results of the universal density function (DFT). The frontier electron orbital studies show that N-CQDs@In 2 O 3 has more abundant electron clouds. The good moisture resistance enables its stable performance in humid environment. UV sensitization is an effective way to improve the sensitivity of optical fiber gas sensor, which is of great significance for detecting the acetone gas with ultra-low concentration.
研究领域:
材料科学
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传感器技术
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光学工程
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高影响因子
DYES AND PIGMENTS
·
2025
·
IF 4.2
Bin Xu,Jiajie Cai,Maohua Hou,Meiting Zhu,Xuanhao Sheng,Haolin Wang,Li Pan,Xiaohui Lu
Since traditional anti-counterfeiting technology with a single decryption mode is easy to be cracked and imitated, the development of new anti-counterfeiting technology with complex response modes has significance. Here, we propose a preparation method for solvent/ultraviolet (UV) dual-responsive anti-counterfeiting coating based on fluorescent structural color pigments. The fluorescent non-iridescent structural color pigments based on CB@SiO 2 /CQDs core-shell nanospheres were prepared by carbon black (CB) as the core, and SiO 2 loaded with carbon quantum dots (CQDs) as the shell. The structural design of CB as the core can enhance the structural color saturation and enhance the chromatic stability. In addition, the CQDs embedded in SiO2 shells impart fluorescence function to structural color pigments, while effectively avoiding fluorescence quenching caused by agglomeration. Eventually, the solvent/UV dual-responsive photonic crystal anti-counterfeiting coatings were prepared by alternating spraying and superhydrophobic modification, consisting of structurally colored CB@SiO2, CB@SiO2/CQDs nanospheres and SiO 2 nanospheres. The top SiO 2 layer became transparent when the coatings were exposed to water. The underlying CB@SiO 2 and CB@SiO 2 /CQDs composite coatings were impervious to water infiltration, owing to the superhydrophobic properties. The structural color and fluorescent pattern information can be observed under natural light and UV illumination, respectively, after the SiO 2 layer became transparent. The solvent/UV dual-responsive anti-counterfeiting technology independent of large refractive index contrast was achieved by the above method, and this dual-responsive anti-counterfeiting strategy of fluorescence and structural color combination has a broad prospect in the field of anti-counterfeiting and information encryption.
研究领域:
材料科学
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光学
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防伪技术
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2026
·
IF 5.4
Jitai Li,Yunlan Xu,Dengjie Zhong
In this work, an efficient nitrogen-doped carbon dots (N-CQDs) doped Bi 2 MoO 6 /CuMn 2 O 4 heterojunction photoanode (N-CQDs/Bi 2 MoO 6 /CuMn 2 O 4 ) was successfully prepared via a facile hydrothermal-coupling strategy, and it was integrated with a Cu cathode to build a PFC for concurrent electricity generation and organic pollutant degradation. Approximately 92% of RhB was eliminated, accompanied by photocurrent and power output values of 8.3 mA·cm −2 and 51.0 μW·cm −2 , respectively. In addition, the open-circuit voltage and photoconversion efficiency were measured as 0.60 V and 0.12%. The superior performance of PFC originates from the integrated action of carrier separation of Bi 2 MoO 6 /CuMn 2 O 4 Z-scheme heterojunction and electron-storage function of N-CQDs, which reinforces visible-light harvesting, suppressed charge recombination, accelerates the interfacial electron transfer and sustains strong redox potentials. The degradation process involved the participation of both radical species (•OH, •O 2 ⁻ ) and non-radical species (h + ). Due to the formation of local Schottky-like contact between Bi 2 MoO 6 /CuMn 2 O 4 and N-CQDs, N-CQDs act as an efficient electron mediator, which facilitates the generation of reactive oxygen species and further enhances the degradation efficiency. This work provides a new insight into constructing quantum-dot-mediated heterojunction photoanode.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 3
·1977-1993
·
IF 4.682
Weng Peijie,Cai Qing,Wu Huadong,Zhang Linfeng,Wu Kun,Guo Jia
The flower-like CQDs/ S -Bi 4 O 5 Br 2 composites photocatalyst with high visible-light response is prepared by adjusting bismuth-rich, S -doped, and introducing carbon quantum dots (CQDs) into the bismuth oxybromide (BiOBr). Particularly, the prepared C 10 /S 6 –Bi 4 O 5 Br 2 composite shows the highest degradation efficiency for the ciprofloxacin (CIP) under visible-light irradiation with the apparent rate constants k of 0.03798 min −1 , which is 26.3 times and 10.1 times higher than that of BiOBr and Bi 4 O 5 Br 2 , respectively. The sulfur doping leads to the increase of the specific surface area and decreases of the band gap but retains the original flower-like morphology of Bi 4 O 5 Br 2 . Compared to the pure Bi 4 O 5 Br 2 , CQDs/Bi 4 O 5 Br 2 , and S -Bi 4 O 5 Br 2 , the CQDs introduction and S -doping can improve both of the light absorption range and intensity, as well as the charge transfer efficiency for the C 10 /S 6 –Bi 4 O 5 Br 2 composites. Furthermore, because of the combination of the CQDs and S doped for the Bi 4 O 5 Br 2 composites, the separation efficiency of photo-generated carriers is improved with the recombination rate greatly reduced. Graphical Abstract
研究领域:
材料科学
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环境科学
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高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 12
·1-7
·
IF 5.479
Li Shuhuai,Ma Xionghui,Pang Chaohai,Tian Hai,Xu Zhi,Yang Yan,Lv Daizhu,Ge Huilin
A fluorometric assay is described for the determination of Cd(II) in environmental and agricultural samples. It is making use of a molecularly imprinted polymer (MIP) and aptamer as dual recognition units, while carbon quantum dots (co-doped with sulphur and nitrogen) and gold nanoparticles (SN-CQD/Au) act as the fluorophores. The aptamer-modified MIP was placed on an SN-CQD/Au-modified indium tin oxide glass electrode. Cd(II) was detected with high selectivity by the recognition sites of the aptamer in the MIP. Fluorescence, with excitation/emission peaks at 370/430 nm, is quenched by Cd(II). Response is linear in the 20 pM to 12 nM concentration range. The detection limit is 1.2 pM. The sensor is selective for Cd(II), and recoveries from spiked waters, soils and vegetables real-world samples range between 82.1 and 113.9%.
A fluorescence sensor composed of a molecularly imprinted polymer and an aptamer as a dual identification system for Cd 2+ coupled with and carbon quantum dots (co-doped with sulphur and nitrogen) and gold nanoparticles (SN-CQDs/Au) as fluorescent element that can detect Cd 2+ with high selectivity by a dual-recognition mechanism.
研究领域:
分析化学
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环境科学
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材料科学
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农业化学
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PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Mingjun Cen,Yaqi Cao,Yuanzhi Zhu,Wenchao Peng,Yang Li,Fengbao Zhang,Qing Xia,Xiaobin Fan
High-performance sensors for the selective and sensitive identification of chromium(VI) [Cr(VI)] with high toxicity and carcinogenicity are urgently demanded. Carbon quantum dots (CQDs) as outstanding fluorescence sensors were widely applied to detect Cr(VI). Herein, the covalent organic frameworks (COFs) were utilized as a homogeneous precursor to prepare CQDs with N heteroatom by microwave-assisted chemical tailoring. The oxidation degree of COFQDs was adjusted by controlling the amount of sodium persulfate. The results showed that the oxidation degree has a significant influence on the fluorescence performance of COFQDs. In particular, the obtained COFQDs, which possess unique C–N conjugated structures and controllable oxidation degree, displayed a high quantum yield (QY) of up to 26%. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) results indicated that the cutting mechanism involved the breaking of hydrogen bonds and imine bonds, accompanied by partial hydrolysis. In addition, the COFQDs demonstrated promise as efficient “on–off” photoluminescence sensors to detect Cr(VI), providing great advantages including rapid response, large-scale monitoring, and high selectivity. Also, the COFQDs–Cr(VI) system was also used as an “off–on” fluorescence sensor for the detection of ascorbic acid (AA). This study is expected to open an avenue for preparing CQDs with excellent properties using suitable precursors and optimizing oxidation degree.
研究领域:
材料科学
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环境科学
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分析化学
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DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2024
·
IF 5.7
Jianguo Hou,Binyun Xia,Kunpeng Niu,Jiale Wang,Jinhua Li,Ning Wang
Background Cobalt, an essential trace element, is vital for maintaining human nervous system function, aiding in DNA synthesis, and contributing to red blood cell production. It is helpful for disease diagnosis and treatment plan evaluation by precisely monitoring its concentration changes in the human body. Despite extensive efforts made, due to its ultra-low concentration, the current limit of detection (LOD) as reported is still inadequate and cannot be satisfied with the precise clinical applications. Therefore, it is crucial to develop novel label-free sensors with high sensitivity and excellent selectivity for detecting trace amounts of Co 2+ . Results Here, an ultrasensitive optical fiber SPR sensor was designed and fabricated for label-free detection of Co 2+ with ultra-low concentration. It is achieved by modifying the carboxyl-functionalized CQDs on the AuNPs/Au film-coated hetero-core fiber, which can specifically capture the Co 2+ , leading to changes in the fiber's surface refractive index (RI) and subsequent SPR wavelength shifts in the transmission spectrum. Both the Au film and AuNPs on the fiber are modified with CQDs, leveraging their large surface area to enhance the number of active sites and probes. The sensor exhibits an ultra-high sensitivity of approximately 6.67 × 10 19 nm/M, and the LOD is obtained as low as 5.36 × 10 −20 M which is several orders of magnitude lower compared to other conventional methods. It is also experimentally demonstrated that the sensor possesses excellent specificity, stability, and repeatability, which may be adapted for detecting real clinical samples. Significance The CQDs-functionalized optical fiber SPR sensor exhibits substantial potential for precisely detecting Co 2+ of trace amounts, which is especially vital for scarce clinical samples. Additionally, the sensing platform with sample sensor fabrication and measurement configuration introduces a novel, highly sensitive approach to biochemical analysis, particularly adapting for applications involving the detection of trace targets, which could also be employed to detect various biochemical targets by facile modification of CQDs with specific groups or biomolecules.
研究领域:
生物医学工程
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分析化学
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PubMed
高影响因子
JOURNAL OF FLUORESCENCE
·
2024
·
IF 2.6
Ge Ziyang,Du Haiying,Tang Bo,Deng Jie
Carbon quantum dots (CQDs) were greenly synthesized via a single-step hydrothermal method, using the trunks of Bauhinia purpurea as the carbon source. They exhibited good dispersibility, water solubility, high sensitivity, and great stability with a spherical form and a particle size of 2.68 ± 0.32 nm. By utilizing the inner filter effect and dynamic quenching effect, the fluorescence quenching of CQDs can be induced to detect quinoline yellow. Detailed experimental results showed that the change rate of fluorescence intensity of CQDs had a good linear relationship with varying concentrations of quinoline yellow (2–128 µmol/L). It can be clearly observed that the fluorescence quenching occurred within 1 min, its correlation coefficient (R 2 ) is 0.9912, and the detection limit (DL) is 1.7884 μmol/L, substantially lower than the maximum concentration stipulated by the national standard of 209.5 µmol/L. Furthermore, quinoline yellow had been successfully detected in real beverage samples using CQDs, with the recovery rates of 90.6%-110.4% and the relative standard deviation (RSD) ≤ 6.3% and it also showed great anti-interference and selectivity. These findings indicate that the detected quinoline yellow of CQDs possess substantial promise for a wide range of applications within the detected artificial food colors field. Graphical Abstract
研究领域:
食品科学
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材料科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 17
·1-11
·
IF 2.8
Liu Ji,Du Haiying,Jiang Yuqiu,Zhang Lanying,Ma Yanqi,Fu Bingjie,Hu Yao,Kang Heng
Artificial sweetener needs to control the maximum dosage, such as aspartame, cyclamate, saccharin sodium, and sucralose, are mainly used in fruits, jams, beverages, desserts, and dairy products. In this research, a novel label-free fluorescent sensor based on carbon quantum dots (CQDs) were prepared by a one-step hydrothermal method using Eupatorium odoratum L . , as a highly sensitive “turn-on”-type fluorescent probe for the detection of artificial sweetener. They exhibit photoluminous emission at 444 nm under 370 nm excitation, with a quantum yield of 20.36%. Under optimal conditions, the standard curve of aspartame, neotame, and sucralose had good linearity in the concentration range of 0–750 µmol/L, 0–400 µmol/L, and 100–800 µmol/L, respectively, and the linear correlation coefficients were 0.9913, 0.9978, and 0.9974. The CQDs were also shown to selectively react with aspartame, neotame, and sucralose, leading to fluorescence enhancing effect, and low limits of detection were 4.2383 µmol/L, 6.8834 µmol/L, and 7.6576 µmol/L, respectively, which were much lower than the limits of detection for aspartame (1.0194–33.9789 mmol/L), neotame (26.4229–792.6861 µmol/L), and sucralose (0.3772–12.5745 mmol/L) in various foodstuffs as stipulated in GB 2760-2014. The results indicated our developed sensor based on E. odoratum L . CQDs has great application prospects for artificial sweeteners detection.
研究领域:
分析化学
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食品科学
·
材料科学
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2023
·
IF 3.6
Zhaofa Li,Quanxiu Zhou,Palanivel Sathishkumar,Liang Peng,Qunfang Wang,Feng Long Gu
The present work fabricated a novel dual-emission responsive ratiometric fluorescent hybrid nanoprobe using a mixture of blue fluorescence-emitting N-Doped Carbon Quantum Dots (N-CQDs) and red fluorescence-emitting l -cysteine-capped CdSe/ZnS Quantum Dots (Lcys-CdSe/ZnS QDs). The addition of Cu 2+ resulted in the strong and specific fluorescence quenching in Lcys-CdSe/ZnS QDs while N-CQDs retained their fluorescence intensity. Further exploration of the nanoprobe showed that the detection limit was 3.78 × 10 −9 M and the linear range was below 3.2 × 10 −6 M. The nanoprobe possessed excellent anti-interference in the Cu 2+ determination and its application was successful in natural water samples. Experimental results suggested that the superficial left cysteine (Lcys) combines with Cu 2+ causing static quenching. Results of density functional theory (DFT) computation explained that Cu 2+ has the greatest possibility to combine with surficial Lcys and furthermore illustrated the role of the combination in static quenching. The work showed one of origin of the selectivity of the nanoprobe and a potentially guidance to design high selective ratiometric fluorescent nanoprobes.
研究领域:
分析化学
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材料科学
·
环境科学
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DOI
高影响因子
TALANTA
·
2019
·
IF 4.916
Yuehai Li,Jiabai Cai,Fengjiao Liu,Hui Yang,Ye Lin,Shunxing Li,Xuguang Huang,Luxiu Lin
Using chloroauric acid as precursor and β-cyclodextrin (β-CD) as reducing agent and stabilizer, β-CD@AuNPs with negative charge were synthesized by one-step colloidal synthesis method. The positive charged carbon quantum dots (CQDs) were synthesized by one-step of sonication of cetylpyridinium chloride . Under the role of static electricity, the fluorescence resonance energy transfer (FRET) occurred between CQDs and β-CD@AuNPs. CQDs and β-CD@AuNPs served as the fluorescence energy donors and receptors, respectively, i.e., the fluorescence of CQDs was turned off by β-CD@AuNPs. Based on the specific host-guest recognition between the inner cavity of β-CD and cholesterol, CQDs was replaced by cholesterol, the FRET could be interrupted, and then the fluorescence of CQDs was turned on. A good linear relationship between cholesterol concentration (10–210 μmol L −1 ) and fluorescence intensity was obtained and the LOD was 343.48 nmol L −1 . Because of excellent fluorescence quenching ability of FRET, the analytical performance (including LOD and linear scope) of such a turn off-on fluorescent nanosensor (e.g., CQDs/β-CD@AuNPs) was better than nanosensor only via competitive host-guest recognition (e.g., β-CD functionalized CQDs). The synergistic effect of competitive host-guest recognition and FRET was proved. Because of selective recognition, ultrasensitive, wide linear range, and strong anti-interference ability, CQDs/β-CD@AuNPs as a turn off-on fluorescent nanosensor was developed to determine cholesterol in porcine serum.
研究领域:
分析化学
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纳米技术
·
生物医学工程
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）