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Highly Sensitive and Selective Fluorescent Detection of Gossypol Based on BSA-Stabilized Copper Nanoclusters
摘要： In this paper, ?uorescent copper nanoclusters (NCs) are used as a novel probe for the sensitive detection of gossypol for the ?rst time. Based on a ?uorescence quenching mechanism induced by interactions between bovine serum albumin (BSA) and gossypol, ?uorescent BSA-Cu NCs were seen to exhibit a high sensitivity to gossypol in the range of 0.1–100 μM. The detection limit for gossypol is 25 nM at a signal-to-noise ratio of three, which is approximately 35 times lower than the acceptable limit (0.9 μM) de?ned by the US Food and Drug Administration for cottonseed products. Moreover, the proposed method for gossypol displays excellent selectivity over many common interfering species. We also demonstrate the application of the present method to the measurement of several real samples with satisfactory recoveries, and the results agree well with those obtained using the high-performance liquid chromatography (HPLC) method. The method based on Cu NCs offers the followings advantages: simplicity of design, facile preparation of nanomaterials, and low experimental cost.
关键词： probe,?uorescence,copper nanoclusters,gossypol
更新于2025-11-14 17:04:02
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Diamond like carbon films with embedded Cu nanoclusters deposited by reactive high power impulse magnetron sputtering: Pulse length effects
摘要： In the present study diamond like carbon films with embedded Cu nanoclusters (DLC:Cu films) were deposited by reactive high power impulse magnetron sputtering (HIPIMS). HIPIMS pulse length (pulse on time) effects were considered. The dependence of the chemical composition on pulse length was found. Structure of diamond like carbon matrix of the nanocomposite films studied by Raman scattering spectroscopy has indicated weak increase of the sp3/sp2 carbon bond ratio with HIPIMS pulse length. Studies of the shape and dimensions of copper nanoclusters performed by He ion microscopy have shown that increase of the HIPIMS pulse on time resulted in increased number of the nanoclusters and subsequent increase of the Cu nanoclusters size. Study of optical properties revealed surface plasmon resonance effect in all investigated films. Correlation between the optical absorption spectra and photoexcited charge carrier relaxation time recorded by the pump probe spectroscopy was found. The highest relaxation time was observed at the excitation wavelength close to the absorption surface plasmon resonance peak wavelength The highest maximum relaxation time was observed for the DLC:Cu film deposited by using HIPIMS pulse of 400 μs on time. It was explained by the dependence of the relaxation time on Cu nanocluster size.
关键词： Pulse length,Diamond-like carbon,High-power pulsed magnetron sputtering,Structure,Optical properties,X-ray photoelectron spectroscopy,Copper,Nanoclusters
更新于2025-09-23 15:23:52
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[IEEE 2019 20th International Conference on Electronic Packaging Technology(ICEPT) - Hong Kong, China (2019.8.12-2019.8.15)] 2019 20th International Conference on Electronic Packaging Technology(ICEPT) - Self-Assembled Copper Nanoclusters-Based White Light Emitting Diodes With High Performance
摘要： Metal nanoclusters, composed of a few to a hundred atoms, whose size is close to the Fermi wavelength of electrons, have become a new type of phosphor materials due to their unique electronic structure and excellent performance. And metal nanoclusters have been applied in various applications, such as bioimaging, chemical biosensing, optoelectronic devices, etc. At present, researchers have synthesized and studied gold and silver nanoclusters, but Au and Ag nanoclusters have one drawback: expensive. At the same time, copper nanoclusters have attracted people's attention because of their non-toxicity, large Stokes shift and economy. In this paper, we fabricated 1-dodecanethiol (DT)-capped self-assembled copper nanoclusters in colloidal solution with yellow light emission and characterized the prepared self-assembled copper nanoclusters by UV–visible spectra, TEM and PL characterization methods. Self-assembled copper nanoclusters were used as color conversion layers for the manufacture of white light-emitting diodes. The prepared white LED has good color properties, the color rendering index was 79.3, the CIE color coordinates located at (0.3213,0.3255) and the color temperature was 6067K. This indicates that copper nanoclusters show potential for applications in white lighting emitting diodes as a new type of low-cost and superior photoluminescent material candidates.
关键词： Copper Nanoclusters,Photoluminescence,White Light Emitting Diodes,Quantum Dots
更新于2025-09-23 15:21:01
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Copper nanoclusters @ nitrogen-doped carbon quantum dots-based ratiometric fluorescence probe for lead (II) ions detection in porphyra
摘要： A novel ratiometric fluorescence probe was proposed for detecting lead (II) ions (Pb2+) in porphyra, the approach was based on copper nanoclusters and nitrogen-doped carbon quantum dots (CuNCs-CNQDs). In this probe, the CuNCs delivered the response signal, the fluorescence of which was enhanced by Pb2+ due to the aggregation-induced emission enhancement (AIEE) between Pb2+ and CuNCs. The CNQDs provided the self-calibration signal, whose fluorescence remained almost unchanged in coexistence with Pb2+. According to the change of fluorescence intensity ratio between the fluorophores, CuNCs–CNQDs nanohybrid was used as ratiometric probes for the sensitive detection of Pb2+ in the range of 0.010 to 2.5 mg L-1, with a detection limit of 0.0031 mg L-1. Finally, the probe was successfully applied to detect Pb2+ in porphyra with relative standard deviations (RSDs) lower than 5%. This study provides a straightforward, stable, and sensitive approach for detecting Pb2+ in porphyra.
关键词： Lead (II) ions,Ratiometric fluorescence probe,Aggregation-induced emission enhancement,Copper nanoclusters,Nitrogen-doped carbon quantum dots
更新于2025-09-23 15:21:01
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A ratiometric fluorescent sensor for sensitive detection of UDG using poly(thymine)-templated copper nanoclusters and DAPI with exonuclease III assisted amplification
摘要： As one of critical base excision repair enzymes, uracil-DNA glycosylase (UDG) can specifically repair uracil-induced DNA damage to maintain the genome integrity of organisms. Moreover, abnormal expression of UDG is related to various cancers and other serious diseases. Therefore, it is essential to accurately and sensitively monitor UDG activity. In this work, a ratiometric fluorescence method using poly-(thymine) DNA template copper nanoclusters (Cu NCs) and 4',6-diamidino-2-phenylindole (DAPI) as the output signals is developed for simple, selective, and sensitive detection of UDG. A double-stranded DNA (dsDNA) consisting of a uracil-containing single chain and a trigger sequence is designed as a substrate dsDNA. Meanwhile, another dsDNA comprising 30 pairs of A-T bases ((AT)30 dsDNA) is designed to be partially complementary to the trigger chain. The (AT)30 dsDNA itself has no blunt or recessed 3’ end and cannot be cut by exonuclease III (Exo III). With the Exo III-assisted amplification, adding UDG results in the success synthesis of red-emissive Cu NCs, while the dsDNAs in the system are hydrolyzed and the fluorescence signal of DAPI is weak. In contrast, without addition of UDG, the fluorescence intensity of Cu NCs is low, while the DAPI emits significantly enhanced fluorescence signal. The proposed method presents a detection limit of 5.0 × 10?5 U mL-1 and can be applied to the Hela cell lysate sample with satisfactory results. Additionally, the kinetic parameter is studied and the UDG inhibition effect is evaluated. In summary, this work provides a potential platform for DNA repair enzyme-related analysis and clinical diagnosis.
关键词： Uracil-DNA glycosylase,Ratiometric fluorescent sensor,Poly-(thymine) templated copper nanoclusters,DAPI,Exo III-assisted amplification
更新于2025-09-19 17:15:36
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Determination of the activity of T4 polynucleotide kinase phosphatase by exploiting the sequence-dependent fluorescence of DNA-templated copper nanoclusters
摘要： A fluorometric method is described for the determination of the activity of the enzyme T4 polynucleotide kinase phosphatase (T4 PNKP). A short 3′-terminus phosphorylated DNA strand is hybridized with a long DNA strand to produce a partially double-stranded DNA (dsDNA) substrate. On addition of T4 PNKP, the substrate is dephosphorylated to generate the long dsDNA, and then the long dsDNA acted as a template for synthesizing copper nanoclusters (CuNCs). The dsDNA-templated CuNCs display fluorescence with excitation/emission peak wavelengths of 340/570 nm. The fluorescence is DNA sequence-dependent. A DNA substrate was designed to enhance fluorescence and to reduce the background in order to improve the sensitivity of the assay. The assay has an analytical range that extends from 0.07 U mL?1 to 15 U mL?1 and a detection limit of 0.06 U mL?1.
关键词： Near-zero background,Label-free,Copper nanoclusters,T4 polynucleotide kinase phosphatase activity,Fluorescent biosensing
更新于2025-09-10 09:29:36
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Label-free detection of folic acid using a sensitive fluorescent probe based on ovalbumin stabilized copper nanoclusters
摘要： In this work, ovalbumin (OVA) stabilized copper nanoclusters (OVA-Cu NCs) were prepared through a simple protein-stabilized synthetic method and applied for the sensitive determination of FA. Cu2+ ions were directly reduced to Cu (0) by a mild reducing agent, N2H4·H2O, at room temperature without any other complicated procedure such as adjusting pH and controlling the temperature of the reaction mixture. The as-prepared OVA-Cu NCs showed good chemical stability, wonderful water solubility and excellent biocompatibility. The OVA-Cu NCs were obtained with an average particle size of 2.0 nm and good dispersibility in aqueous solution. They also showed strong red emitting at 625 nm with a quantum yield of 3.95%. The OVA-Cu NCs were then applied for label-free detection of FA based on a static quenching mechanism. The linear calibration curve of detecting FA served from 0.5 μM -200 μM with the detection limit of 0.18 μM. In addition, the developed method was also successfully applied to determine the content of FA in tablet, spinach, orange juice and biological samples with quantitative spike recoveries from 96.9% to 100.9%. For these reasons, the developed OVA-Cu NCs-based fluorescent strategy can thus offer a convenient label-free biosensor platform for the detection of FA in biomedical applications.
关键词： label-free detection,folic acid,red emitting,copper nanoclusters
更新于2025-09-09 09:28:46
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Determination of the activity of alkaline phosphatase based on?aggregation-induced quenching of the fluorescence of?copper nanoclusters
摘要： A rapid method is described for synthesis of copper nanoclusters (CuNCs) by utilizing L-histidine as the stabilizer and ascorbic acid (AA) as the reductant. The CuNCs display blue-green fluorescence with excitation/emission peaks at 390/485 nm. A sensitive fluorometric assay was worked out for determination of alkaline phosphatase (ALP) activity. If the ALP substrate p-nitrophenylphosphate (PNPP) is enzymatically hydrolyzed, it forms p-nitrophenol (PNP) which reduces the fluorescence of CuNCs because its absorption band at 410 nm overlaps the excitation peak of CuNCs at 390 nm. In addition, the amino groups and imidazole groups on the surface of CuNCs possibly form a complex with the phenol groups of PNP. This induces aggregation-induced quenching of the fluorescence of CuNCs. The fluorescent probe has a linear analytical range that extends from 0.5 mU·mL?1 to 40 mU·mL?1 and a detection limit of 45 μU·mL?1.
关键词： Alkaline phosphatase,Aggregation-induced quenching,Fluorometry,Inner filter effect,L-Histidine,Copper nanoclusters
更新于2025-09-04 15:30:14
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Synthesis of novel luminescent copper nanoclusters with substituent driven self-assembly and aggregation induced emission (AIE)
摘要： We demonstrate a novel strategy to synthesize highly stable luminescent mercaptoimidazole-capped copper nanoclusters (CuNCs). Herein we depict that a simple modification of substituents on the mercaptoimidazole ligand dictates the self-assembly and photophysical properties of the clusters. These CuNCs showed aggregation induced emission (AIE) with a large Stokes shift (Dk 4 200 nm), and the formation of clusters corresponding to Cu4L3 was confirmed by MALDI-TOF mass spectrometric analyses. Interestingly, these nanoclusters e?ectively internalize into mammalian cells while retaining their fluorescent properties and exhibit negligible toxicity.
关键词： mercaptoimidazole-capped,luminescent copper nanoclusters,AIE,aggregation induced emission,self-assembly
更新于2025-09-04 15:30:14