TALANTA
·
2021
·
IF 6.057
Bin Lai,Haitao Wang,Wentao Su,Zhouping Wang,Bei-Wei Zhu,Chenxu Yu,Mingqian Tan
Cadmium contamination is a severe food safety risk for human health. Herein, a long afterglow “off-on” phosphorescent aptasensor was developed based on phosphorescence resonance energy transfer (PRET) for the detection of Cd 2+ in complex samples which minimizes the interference of background fluorescence. In this scheme, initially the phosphorescence of Cd 2+ -binding aptamer conjugated long afterglow nanoparticles (Zn 2 GeO 4 :Mn) was quenched by black hole quencher 1 (BHQ 1 ) modified complementary DNA. Upon encountering of Cd 2+ , the aptamer interacted with Cd 2+ and the complementary DNA with BHQ 1 was released, leading to phosphorescence recovery. The content of Cd 2+ could be quantified by the intensity of phosphorescence recovery with 100 μs gate time (which eliminated the sample autofluorescence) with a linear relationship between 0.5 and 50 μg L −1 and a limit of detection (LOD) of 0.35 μg L −1 . This method was successfully demonstrated for Cd 2+ detection in drinking water and yesso scallop samples. The “off-on” phosphorescent aptasensor based on PRET of long afterglow nanomaterials could be an effective tool for Cd 2+ detection in food samples.
研究领域:
食品科学
·
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Xiutan Peng,Yuqing Xu,Weiye Zhou,Yiting Tao,Haiyan Fu,Siying Che,Yuanbin She
Evaluation of glyphosate content in tea products is a food safety topic worthy of social attention due to most glyphosate is dissolved in water as well during tea brewing. So it requires that the probe can not only realize the sensitive detection of glyphosate, but also has good water solubility to realize the practical detection of glyphosate in water-based samples such as tea infusions. To better suit the demands of practical applications, a water-soluble quinoline fluorescent ionic liquid probe (EHQCA) was synthesized for the sensitive detection of glyphosate by fluorescence “turn-off-on”. Interestingly, the introduction of the imidazolium cation module easily achieved the switchable water solubility of the fluorophore without complex group modification. According to the different competitive coordination ability, EHQCA-Cu 2+ with fluorescence-off was first constructed, and then Cu 2+ was captured by glyphosate to restore fluorescence. The probe behaved a sensitive (detection limit of 2.2 × 10 −8 M), rapid (less than 5 s) and selective response (among 20 interferences) to glyphosate. Meaningfully, satisfactory recovery (98–103 %) and low RSD (< 1.27 %) were obtained in 12 green tea infusions from different varieties and origins. Therefore, the ionic liquid-based fluorescent probes offers strong technical support for the detection of pesticides in foods such as tea, and have broad prospects in the field of food safety monitoring and evaluation.
研究领域:
分析化学
·
食品安全
·
环境监测
·
荧光光谱
·
农药检测
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2025
·
IF 4.6
Yaohong Gu,Qianqian Pang,Zhiting Deng,Zhichao Chen,Yaling Yang
Herein, a novel fluorometric approach is developed for the precise quantification of nicotine. This method utilized the derivatizing reaction between o-phthalaldehyde (OPA) and reduced glutathione (GSH), and derivatized product with tricyclic conjugated structure generate fluorescent emission. And the derivative exhibits a quantum yield of 33.46 % and distinct fluorescence “turn-off” quenching behavior in the presence of Cu 2+ ions due to the GSH-Cu 2+ complex formation. More importantly, when nicotine is introduced reaction system, the fluorescence restored (“turn-on”) based on the nicotine-Cu 2+ complex formation. Therefore, a fluorimetric sensor for nicotine detection is developed with lower detection limit (LOD) of 0.21 μg/mL. The developed method was successfully utilized to analyze nicotine content in electronic cigarette and cigarette bag samples, yielding satisfactory recovery rates ranging from 85.2 % to 111.8 %. The obtained results demonstrated comparable accuracy and confirmed the method's reliability and practical applicability.
研究领域:
分析化学
·
生物传感
·
药物代谢
·
环境毒理学
·
分子诊断
·
转化医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Yiran Fan,Ziyou Ding,Jia Chen,Chengyu Li,Yingchao Han
Alkaline phosphatase (ALP) is an essential enzyme widely distributed in the human body, and it can hydrolyze pyrophosphate (PPi) under alkaline conditions. Therefore, ALP and PPi activities are associated with many diseases and it is crucial to develop sensitive and selective methods for detecting ALP and PPi. Herein, poly(acrylic acid) (PAA)-Ca2+(Ce3+) nanoclusters fluorescent probe was synthesized aiming to detect PPi and ALP quantitatively. The nanoclusters present monodisperse, and their particle size is 0.9–2.4 nm. The probe exhibits no fluorescence due to electron transfer; whereas it can combine with PPi to yield fluorescence increase, arising from the enhanced electric-dipole transition of Ce3+ under the ligand effect of PPi. Moreover, the probe displays good selectivity to PPi, and the fluorescence changes display a linear relationship with PPi concentration of 3–20 mM (y = 11.29x – 23.47, R2 = 0.994). Furthermore, the probe was mixed with PPi to form PAA-Ca(Ce):PPi nanoparticle (Monodisperse, average size: 1.94 nm) and showed high fluorescence selectivity and responsiveness to ALP due to the ALP hydrolyzing effect and the fluorescence difference between PAA-Ca(Ce):PPi and PAA-Ca(Ce):Pi. Based on the relationship between the fluorescence reduction rate of the probe and the logarithm of ALP concentration (y = 0.0594x – 0.00111, 5–200 U/L, R2 = 0.996), ALP was successfully detected quantitatively, and the detection limit is calculated to be 0.62 U/L. Through this approach, we developed a fluorescence “turn-on” for PPi detection and “turn-off” for ALP detection. This study provides a promising strategy for the diagnosis of diseases related to PPi and ALP.
研究领域:
分析化学
·
生物材料
·
生物医学工程
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2020
·
IF 5.977
Zihan Wang,Li Zhang,Yumin Hao,Wenjuan Dong,Yang Liu,Shengmei Song,Shaomin Shuang,Chuan Dong,Xiaojuan Gong
The fluorescent sensor, especially ratiometric fluorescent sensor, is one of the most important applications for CQDs , which is becoming a research hotspot. Herein, carbon quantum dots co-doped with nitrogen, phosphorus and chlorine (NPCl-CQDs) were synthesized by acid-base neutralization reaction exothermic carbonization method. The as-fabricated NPCl-CQDs could emit blue fluorescence and possess excellent fluorescence properties. Based on the FRET , multifunctional and ratiometric fluorescent sensors for “on-off-on” sequential determination of riboflavin , Ag + , and Cys with good selectivity and high sensitivity were established. The linear range of riboflavin, Ag + , and Cys are 0.50–10.18 μM and 15.89–27.76 μM, 0.66–1.46 mM and 1.50–4.20 mM, and 0.01–0.15 μM and 0.15–0.36 μM with the limit of detection of 3.50 nM, 26.38 μM, and 0.96 nM, respectively. Furthermore, the sensors were successfully used to determine riboflavin, Ag + , and Cys in tablets, river water, and human urine with the recoveries of 95.2–104.0%, 95.6–102.0%, and 94.8–106.4%, respectively. More importantly, the as-constructed “on-off-on” NPCl-CQDs-based ratiometric fluorescent sensors were applied for detecting riboflavin, Ag + , and Cys in HeLa cells with satisfying results. The finding of this study shows the feasibility and effectiveness of the NPCl-CQDs as the available ratiometric fluorescent sensors for the determination of riboflavin, Ag + , and Cys in real samples and living cells.
研究领域:
分析化学
·
纳米技术
·
生物医学工程
·
荧光光谱
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Qin Yingfeng,Huang Ruiqi,Ye Gao-Jie
The analysis of glyphosate is essential to agricultural production, environment protection and public health. Herein, we proposed a fast and convenient “on-off-on” fluorescence platform for sensitive detection of glyphosate via Cu2+ modulated g-C3N4 nanosheets. The fluorescence of the system was quenched by Cu2+. With the presence of glyphosate, the fluorescence could be restored due to the formation of Cu2+- glyphosate complex. The proposed method was cost-effective with label-free and enzyme-free. Moreover, it exhibits high sensitivity with a low detection limit of 0.01 μg/ml. Furthermore, the proposed method has been successfully monitored glyphosate in real samples.
研究领域:
农业科学
·
环境科学
·
分析化学
·
公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Guo Wei,Chuanliang Wang,Rui Wang,Xuhui Geng,Jinhua Li,Lingxin Chen,Zhihua Song
In this study, a novel carbon dots-based system was developed for the sequential quantification of Au 3+ and L-cysteine (L-Cys). The system comprises N,F-doped carbon dots (N,F-CDs), a custom-designed miniaturized fluorimeter, and test strips. The N,F-CDs exhibit outstanding optical properties, including a large Stokes shift (127 nm) and high fluorescence intensity. The test strips offer low-cost, low-volume sample consumption, while the miniaturized fluorimeter provides high sensitivity in a compact format. The system demonstrated excellent analytical performance, including high sensitivity (limits of detection: 0.048–0.488 μmol/L for Au 3+ and 8.7–40.9 nmol/L for L-Cys), minimal matrix interference (within ±20 %), high accuracy (97.5 % to 104.5 % for Au 3+ , 97.6 % to 107.5 % for L-Cys), good precision (2.9 % to 4.5 % for Au 3+ , 1.2 % to 7.0 % for L-Cys), robust stability, and strong inter/intra-day reproducibility (relative standard deviations ≤2.1 %). Furthermore, it showed high selectivity for Au 3+ and L-Cys in complex matrices such as tap water, milk, and lemon-flavored beverages.
研究领域:
分析化学
·
纳米技术
·
环境监测
·
生物分析
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2025
·
IF 5.1
Tingjie Jiang,Na Yang,Ziyi Wang,Haoran Zhang,Na Li,Yongying Chen,Mingkai Wei,Xuejie Zhang,Bingfu Lei
In this study, a carbon dot-based ratiometric fluorescence (RF) probe was used as a fluorescent "on-off-on" sensor to detect Fe3+ and the pesticide amitrole (AMT). The RF probe consists of orange carbon dots (O-CDs) and blue carbon dots (B-CDs). B-CDs forms a ground-state complex with Fe3+ which leads to fluorescence quenching, while the addition of AMT restores fluorescence. Based on this "on-off-on" process, a quantitative detection of Fe3+ and AMT is achieved, showing good linearity in the range 0-50 μM and 0-30 μM. The low detection limit of Fe3+ and AMT are as low as 24 nM and 0.18 μM, respectively. In addition, fluorescent color changes are converted into RGB values by a smartphone sensing device., and the concentration of Fe3+ and AMT is determined by colorimetric analysis. The method was further applied to real samples such as lake water, tap water and urine with satisfactory results. Additionally, a portable sensor with a semi-hydrophobic film was fabricated for on-site AMT detection, showcasing practical applicability. This work provides a cost-effective, rapid, and dual-mode strategy for environmental and biological monitoring of Fe³⁺ and AMT.
研究领域:
环境监测
·
分析化学
·
纳米技术
·
生物传感
·
荧光光谱学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2021
·
IF 4.821
Qiaozhen Bao,Dan Lin,Yaoran Gao,Lina Wu,Jinhua Fu,Khuslen Galaa,Xinhua Lin,Liqing Lin
Herein we develop a novel “off–on-off” fluorescent nanosensor for the ultra-sensitive detection of protamine and trypsin based on the as-prepared nitrogen and sulphur doped carbon dots (N,S-CDs) and gold nanoparticles (AuNPs). N,S-CDs were treated as fluorophore, while AuNPs were treated as fluorescence absorber. By experimental studies, the fluorescence quenching mechanism of N,S-CDs by AuNPs was inner-filter effect (IFE). Upon addition of protamine to the mixed aqueous of N,S-CDs/AuNPs, the electrostatic interaction and Au-N bond between protamine and AuNPs resulted in AuNPs aggregation, and the quenched fluorescence of N,S-CDs could be recovered. Protamine is rich in arginine and can be specifically hydrolyzed by trypsin, resulting in the deaggregation of AuNPs and further quenching the fluorescence of N,S-CDs. Thus, we can determine the concentration of protamine and trypsin by measuring fluorescence intensity of N,S-CDs. Under the optimized conditions, the fluorescence intensity showed a good linear relationship with protamine concentration of 20–260 ng/mL with the detection limit of 4.7 ng/mL. Meanwhile, quantitative determination of trypsin in a range from 10 to 140 ng/mL with the detection limit of 4.3 ng/mL can be achieved in this fluorescent nanosensor. This fluorescent nanosensor also showed excellent selectivity, and we successfully applied it for the detection of protamine and trypsin in human urine samples. Based on the above findings, we conclude that this novel “off–on-off” fluorescent nanosensor has great potential in clinical diagnosis.
研究领域:
分析化学
·
纳米技术
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 55
·35763-35769
·
IF 4.036
Pu Li,Chen Luo,Xiaoxiao Chen,Chaobiao Huang
An off–on fluorescence aptasensor was developed for trace thrombin detection based on fluorescence resonance energy transfer (FRET) between CdS QDs and gold nanoparticles (AuNPs). Using DNA pairwise hybridization of the aptamer to the complementary DNA (cDNA), the CdS QDs (energy donor) were tightly coupled to the AuNPs (energy acceptor), resulting in the occurrence of FRET and there was a dramatic fluorescence quenching of CdS QDs (turn off). When the thrombin was added to the fluorescence aptasensor, the specific binding of the aptamer to the target formed a G-quadruplex that caused the AuNPs receptor to detach and the DNA duplex to be disassembled. The process would inhibit the FRET which contribute to the recovery of fluorescence (turn on) and an “off–on” fluorescence aptasensor for thrombin detection was constructed accordingly. Under optimal conditions, the fluorescence recovery showed good linearity with the concentration of thrombin in the range of 1.35–54.0 nmol L−1, and the detection limit was 0.38 nmol L−1 (S/N = 3, n = 9). Importantly, the fluorescence aptasensor presented excellent specificity for thrombin, and was successfully applied to the quantitative determination of thrombin in real serum with satisfactory recoveries of 98.60–102.2%.
研究领域:
分析化学
·
生物传感器
·
分子生物学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LUMINESCENCE
·
2020
·Vol. 36
·期 3
·721-732
·
IF 1.855
Xiaoliang Hao,Shujuan Dai,Jing Wang,Zhigang Fang
In this study, a type of blue-emission fluorescent carbon dot was synthesized using malic acid, urea, and water. This material demonstrates strong stability to heat, ionic strength, and time. It was found that mercury ions can quench the blue fluorescence of the material, and using iodine ions, the fluorescence can be recovered. Hence, we designed an “off–on” mode to detect mercury and iodine ions using the carbon dots. The results showed that this material exhibits good selectivity and recovery rate. Concurrently, imaging experiments showed that this material demonstrates low cytotoxicity and can be used in cell fluorescence imaging. The study concludes that this material has wider application prospects in the future.
研究领域:
材料科学
·
分析化学
·
环境科学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYST
·
2017
·Vol. 142
·期 22
·4221-4227
·
IF 3.885
Hui Liu,Rong Sheng Li,Jun Zhou,Cheng Zhi Huang
N-Acetylcysteine (NAC) plays an important role in optimizing the protective ability of cells as well as in the treatment of some chronic clinical conditions. Unfortunately, current methods for determining NAC based on fluorescence assay strategies remain poorly investigated. In this study, a new fluorescence method for highly sensitive and selective detection of NAC was developed. The detection method employed the fluorescence (FL) signal of branched polyethylenimine-functionalized carbon dots (PEI-CDs) via an off–on mechanism. The detection system was based on the formation of cupric amine complexes by the reaction of Cu2+ ions with surface amino groups on PEI-CDs. The FL of PEI-CDs at 460.0 nm upon exciting at 360.0 nm was quenched as a result of electron transfer between the complexes and PEI-CDs. Upon addition of NAC to Cu2+-CD solution, electron transfer occurred from the mercapto group on NAC to Cu2+, leading to the formation of Cu+ species and the dissociation of cupric amine complexes. As a result, the FL signal of PEI-CDs was turned on since single excited electrons cannot be transferred from PEI-CDs to the cupric amine complexes. The detection limit of this method was 0.56 μM, while the linear response ranged from 5.56 μM to 277.8 μM.
研究领域:
分析化学
·
生物化学
·
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）