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A sensitive polymer dots fluorescent sensor for determination of α-L-fucosidase activity in human serum
摘要： α-L-Fucosidase (AFu) is an important biomarker for early diagnosis of hepatocellular carcinoma and fucosidosis. In this study, a novel, sensitive and selective polymer dots (PDs) fluorescent sensing strategy based on inner filter effect was firstly developed for AFu activity determination. The PDs with a high quantum yield of 53.6% were synthesized by a mild one-pot method. The detection mechanism of this strategy was based on inner filter effect between PDs and p-nitrophenol (PNP) which was the hydrolyzate of 4-nitrophenyl-α-L-fucopyranoside (PNPF) catalyzed by AFu. The absorption of PNP overlapped the fluorescence excitation spectrum of the PDs, which resulted in a fluorescence quenching or weakening of PDs. The sensing system showed a good linear relationship within 0.01-0.9 U L-1 and provided a low AFu detection limit of 0.001 U L-1 (S/N=3). This PDs sensor were successfully applied for the determination of AFu in human serum samples.
关键词： Human serum,α-L-Fucosidase,Polymer dots,Inner filter effect,Fluorescent sensor
更新于2025-11-19 16:46:39
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Dopamine-functionalized upconversion nanoparticles as fluorescent sensors for organophosphorus pesticide analysis
摘要： Organophosphorus pesticide (OP) residues in agricultural products, herbal medicines and environment have attracted increasing concerns because they cause high healthy risk. Herein, a tyrosinase-mediated photoinduced electron transfer system was constructed for OPs analysis by using dopamine-functionalized upconversion nanoparticles (UCNPs) as fluorescent (FL) sensors. Dopamine quinone was produced by tyrosinase-mediated oxidation of dopamine on the surface of UCNPs, which acted as electron accepter to quench the FL emission of UCNPs. The FL quenching was inhibited by OP since it inhibited the activity of tyrosinase. Chlorpyrifos was used as a model analyte to investigate the feasibility of the FL sensor for the analysis of OPs. Under the optimal conditions, chlorpyrifos can be analysed in a wide range of 1.0 ? 1000 ng mL?1, with a detection limit of 0.38 ng mL?1 (3σ). Some other groups pesticides, including organonitrogen pesticide, organochlorine pesticide and chloronicotinyl insecticide all showed negligible interference. The proposed sensor was successfully used to analyse chlorpyrifos spiked in Balloonflower and Angelica with acceptable recovery values of 95.4–120.0%, demonstrating its application potential for real samples. It exhibits some advantages like low cost, high sensitivity and free of autofluorescent interference and photobleaching.
关键词： Tyrosinase,Photoinduced electron transfer,Fluorescent sensor,Organophosphorus pesticide,Upconversion nanoparticles,Chlorpyrifos
更新于2025-11-14 17:15:25
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A reaction-based turn-on fluorescent sensor for the detection of Cu (II) with excellent sensitivity and selectivity: Synthesis, DFT calculations, kinetics and application in real water samples
摘要： A reaction-based turn-on fluorescent chemosensor RhB-Cu, starting from rhodamine B (RhB), for Cu2+ was easily synthesized in two steps. The sensor could selectively detect Cu2+ with a 100-fold fluorescence enhancement among the common metal ions, exhibiting an extremely low detection limit of 4.7 nM. To the best of our knowledge, this was the best record for the detection of Cu2+ with organic fluorescent sensors. There was a 1:1 binding stoichiometry between RhB-Cu and Cu2+ with an association constant of 6.42 × 104 M-1. Noteworthy, it could distinguish Cu2+ from Cu+, which was hard to realize in the previous studies. In addition, the detection mechanism was proposed based on mass spectrometric analysis and density functional theory (DFT) calculations. Kinetic studies were conducted to obtain the activation energy, enthalpy and entropy, so as to elucidate the solvent effect. Interestingly, the kinetic compensation effect (KCE) was uncovered in this work. Finally, RhB-Cu was proved to have the capability to work in real water samples. It would highly contribute to the even better design of fluorescent sensor for Cu2+ in future.
关键词： fluorescent sensor,solvent effect,kinetic compensation effect (KCE),copper,density functional theory (DFT),PET mechanism
更新于2025-10-22 19:38:57
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A Simple Colorimetric and Fluorescent Sensor to Detect Organophosphate Pesticides Based on Adenosine Triphosphate-Modified Gold Nanoparticles
摘要： A simple and dual modal (colorimetric and fluorescent) sensor for organophosphate pesticides with high sensitivity and selectivity using adenosine triphosphate (ATP)- and rhodamine B-modified gold nanoparticles (RB-AuNPs), was successfully fabricated. This detection for ethoprophos afforded colorimetric and fluorescence imaging changes visualization. The quantitative determination was linearly proportional to the amounts of ethoprophos in the range of a micromolar scale (4.0–15.0 μM). The limit of detection for ethoprophos was as low as 37.0 nM at 3σ/k. Moreover, the extent application of this simple assay was successfully demonstrated in tap water samples with high reliability and applicability, indicating remarkable application in real samples.
关键词： multimodal assay,ethoprophos detection,gold nanoparticles,colorimetric and fluorescent sensor,organophosphate pesticides
更新于2025-09-23 15:23:52
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Significant improved selectivity of a fluorescent sensor for Al3+ made from a fluorinated rhodamine B Schiff base
摘要： Two rhodamine B-based Schiff bases (RBF, RBC) with different substituent groups (–F and –COOH) have been synthesized. In order to study the sensing properties of two Schiff bases for metal ions, the interaction of Schiff bases with different metal ions was studied over UV–Vis absorption spectra and photofluorescent spectra. The results show that the RBF is a turn-on fluorescent chemosensor for Al3+ ions with being highly selective and sensitive in ethanol. The value of the fluorescence increase factor shows a good linear relationship with the concentration of Al3+ in the range of 1–9 μM with a detection limit of 0.8 μM. Meanwhile, upon addition of Al3+ or Fe3+ ions, the fluorescence intensity of RBC increased significantly (FAl3+/FFe3+ = 0.77). These studies show that, compared with the carboxyl group (–COOH), the introduction of fluorine atoms (–F) to a rhodamine B-based Schiff base can significantly improve selectivity to Al3+.
关键词： Al3+ ion,Fluorine atoms,Fluorescent sensor,Rhodamine B
更新于2025-09-23 15:23:52
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Fluorescent sensor for copper(II) ion based on coumarin derivative and its application in cell imaging
摘要： A novel fluorescent sensor CHT was designed based on the excellent optical properties of coumarin derivatives. It was synthesized by Schiff base reaction connected by 7-(N,N-diethylamino) coumarin-3-aldehyde and 2-hydrazinobenzothiazole. The sensor CHT displayed exhibited a significant fluorescence quenching at 540 nm upon the addition of Cu2+ ions. And the sensor exhibited good sensitivity, fast response time, high selectivity for Cu2+ ions in the presence of other important relevant metal ions. In addition, CHT fluorescent sensor was successfully applied for fluorescent imaging of Cu2+ ions in A549 and MCF-7 cells, demonstrating its potential applications in live cell imaging.
关键词： fluorescent sensor,coumarin,cell imaging,copper(II) ion
更新于2025-09-23 15:23:52
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Poly(azomethine-urethane) and zeolite-based composite: Fluorescent biosensor for DNA detection
摘要： In the present paper, a highly selective and sensitive fluorescent biosensor based on poly(azomethine-urethane) and zeolite for the determination of DNA molecules was developed. Zeolite was chosen to enhance with anionic or cationic functional groups in polymer matrix and interaction between polymer and DNA. Several parameters such as polymer concentration, pH and incubation time effect on the sensitivity of the fluorescent biosensor were optimized. Linear range was determined between 2.50 and 25.00 nmol/L DNA concentration and limit of detection (LOD) of the biosensor was calculated as 0.095 nmol/L under the optimal conditions. Interference study were also performed in the presence of different amino acids, cations and organic compounds. The results clearly indicated that the tested cations and compounds were not induced a significant fluorescence change and the proposed zeolite-based biosensor was shown a good selectivity for DNA.
关键词： fluorescent sensor,DNA,Zeolite,biosensor
更新于2025-09-23 15:23:52
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Triphenyl phosphate end-capped dicyanomethylene-4H-pyran as a near infrared fluorescent sensor for lysozyme in urine sample
摘要： A dicyano-methylene-4H-pyran (DCM)-based fluorescent probe DCPOP was designed for detecting lysozyme in urine sample. DCPOP showed obvious NIR emission (> 650 nm) avoiding the background fluorescence of urine (450 ? 600 nm). Compared to its mimic (DCPO), DCPOP has a big end-capped triphenyl phosphate (TPP) moiety, which induced good stability in several aqueous with different pH value. Furthermore, the end-capped TPP moiety showed weak interaction with lysozyme, which could modulate the emission signals of DCPOP. As a result, DCPOP could detect the lysozyme in both PBS buffer and real urine samples.
关键词： Fluorescent sensor,Near-infrared (NIR),Dicyano-methylene-4H-pyran-phenol (DCPO),Triphenyl phosphate end-cap,Lysozyme (Lys)
更新于2025-09-23 15:23:52
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1,8-Naphthalimide-based fluorescent sensor with high selectivity and sensitivity for zn2+ and its imaging in living cells
摘要： A novel 4-amino-1, 8-naphthalimide-based fluorescent sensor with iminodiacetic acid as receptor, was developed and applied successfully to image Zn2+ in living cells. Under physiological pH conditions, it demonstrates high selectivity and sensitivity for sensing Zn2+ with about 34-fold enhancement in aqueous solution, with a characteristic emission band of 4-amino-1,8-naphthalimide with a green color centered at 550 nm.
关键词： Naphthalimide,Iminodiacetic Acid,Zinc,Fluorescent Sensor
更新于2025-09-23 15:22:29
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A Film-based Fluorescent Sensor for Monitoring Ethanol-Water Mixture Composition via Vapor Sampling
摘要： In situ, on line, non-contact and fast monitoring of compositions of ethanol-water mixtures via vapor phase sampling remains challenge for years. In this work, we report for the first time of a film-based fluorescent sensor showing unprecedented discriminative ability to the compositions of ethanol-water mixtures. Importantly, ethanol content in the mixtures could vary from 0 to 100% (v/v), the response time is less than 2 s, and the sensing is fully reversible. More importantly, the monitoring was performed via vapor phase sampling, avoiding sample contamination. The principle behind is ascribed to the big difference of the fluorescent quantum yield of the sensing unit, a newly designed and synthesized mono-substituted fluorescent o-carborane derivative (ZPCarb), in the two solvents. In addition, the sensor as developed was successfully used for the determination of ethanol contents in four commercial liquors, suggesting its potential applications in quality control of beverages, monitoring fermentation processes, etc. in a quantitative way.
关键词： Vapor sensing,Ethanol-water mixture,Film-based fluorescent sensor,Fluorescent o-carborane derivative
更新于2025-09-23 15:21:01