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Laser-induced synthesis and photocatalytic properties of hybrid organic–inorganic composite layers
摘要： A laser-based method was developed for the synthesis and simultaneous deposition of multicomponent hybrid thin layers consisting of nanoentities, graphene oxide (GO) platelets, transition metal oxide nanoparticles, urea, and graphitic carbon nitride (g-C3N4) for environmental applications. The photocatalytic properties of the layers were tested through the degradation of methyl orange organic dye probing molecule. It was further demonstrated that the synthesized hybrid compounds are suitable for the photodegradation of chloramphenicol, a widely used broad-spectrum antibiotic, active against Gram-positive and Gram-negative bacteria. However, released in aquatic media represents a serious environmental hazard, especially owing to the formation of antibiotic-resistant bacteria. The obtained results revealed that organic, urea molecules can become an alternative to noble metals co-catalysts, promoting the separation and transfer of photoinduced charge carriers in catalytic composite systems. Laser radiation induces the reduction of GO platelets and the formation of graphene-like material. During the same synthesis process, g-C3N4 was produced, by laser pyrolysis of urea molecules, without any additional heat treatment. The layers exhibit high photocatalytic activity, being a promising material for photodegradation of organic pollutants in wastewater.
关键词： transition metal oxide nanoparticles,urea,photocatalytic properties,hybrid organic–inorganic composite layers,graphene oxide,graphitic carbon nitride,methyl orange,laser-based synthesis,chloramphenicol
更新于2025-11-14 17:04:02
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A cathodic photovoltammetric sensor for chloramphenicol based on BiOI and graphene nanocomposites
摘要： A visible light-activated photocathode fabricated with p-type semiconductor bismuth oxyiodide (BiOI) and graphene (G) was employed to investigate the photovoltammetric behavior of chloramphenicol (CAP). The result indicated that the voltammetric reduction peak of CAP increased to a limiting current platform under photoirradiation, owing to photoelectrocatalytic reduction of CAP on the BiOI-G photocathode. As a result, the cathodic photovoltammogram became sigmoidal in shape. Furthermore, the influences of graphene content in BiOI-G composites, scan rate and light intensity on the photovoltammetric behavior of CAP on the BiOI-G photocathode were systematically investigated. Based on such a BiOI-G electrode, a cathodic photovoltammetric sensor for CAP was proposed, which exhibited a current response linearly proportional to CAP concentration in the range of 0.5 to 50 μmol L-1, with a detection limit (3S/N) of 0.14 μmol L-1. Moreover, the photovoltammetric sensor displayed good reproducibility and high stability. The applicability of the proposed sensor was demonstrated by determining CAP in eye drop and environmental water samples.
关键词： Photovoltammetry,Photoelectrochemical sensor,Chloramphenicol,BiOI,Graphene
更新于2025-09-23 15:23:52
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Fungal In Situ Assembly Gives Novel Properties to CdS <sub/><i>x</i> </sub> Se <sub/> 1a?? <i>x</i> </sub> Quantum Dots for Sensitive Label-Free Detection of Chloramphenicol
摘要： Quantum dots (QDs) are attracting significant attention for the development of sensitive detection methods because of their unique optical properties. Biosynthetic QDs using organisms is a promising alternative route to chemical synthesis because it is a simple and eco-friendly process. Herein, we developed a straightforward and green system for the biological assembly of CdSxSe1?x QDs by Phomopsis sp. XP-8 within 6 h, a more efficient approach than those reported in other organisms. The QDs were shown to have a CdS0.75Se0.25@oligopeptide transporter structure, and the production process was shown to be strongly influenced by intracellular glutathione content. The QDs were monodispersed with a uniform spherical shape of 3.22 ± 0.07 nm in diameter. They exhibited good water solubility and excellent fluorescence properties. The QDs could be extracted and used directly as a sensitive chloramphenicol (CAP) probe via static fluorescence quenching in the linear range from 3.13 to 500 μg/L with a detection limit of 0.89 μg/L. The detection method was highly selective for CAP with minimal interference from other antibiotics and was used to successfully detect CAP in milk samples. Overall, this work has great significance for the development of a fast and simple QD synthesis system via biological assembly.
关键词： Phomopsis sp. XP-8,Chloramphenicol,CdSxSe1?x quantum dots,Biosynthesis,Label-free detection
更新于2025-09-23 15:19:57
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A Simple and Rapid Phosphorescence Probe Based on Mn-Doped ZnS Quantum Dots for Chloramphenicol Detection
摘要： An innovative phosphorescence probe based on Mn-doped ZnS quantum dots (Mn:ZnS QDs) was developed for selective detection of chloramphenicol (CAP) via inner-filter effect (IFE). Mn:ZnS QDs were synthesized by water method and modified with L-Cysteine for better stability, and the average diameter of the nanometer particle was 3.8 nm. With the excitation wavelength at 289 nm, the strong phosphorescence of Mn:ZnS QDs can be emitted at 583 nm. The excitation spectrum of Mn:ZnS QDs was substantially overlapped with the absorption spectrum of the target CAP. The excited light of Mn:ZnS QDs can be absorbed partially by CAP when they coexist, the phosphorescence intensity decreased with the increasing concentration of CAP, and it has a good linear relationship. Under optimal conditions, the linear relational concentration range achieved four orders of magnitude from 25 to 1:2 (cid:1) 10 5 ng (cid:3) mL (cid:4)1 (R 2 ? 0:999), with a detection limit (LOD; S=N ? 3) down to 0.81 ng (cid:3) mL (cid:4)1. The simple, rapid and low cost IFE phosphorescent probe exhibited satisfactory recoveries ranging from 88.9% to 98.5% for CAP analysis in spiked honey, which shows a potential for routine screening of CAP in ensuring the food safety.
关键词： inner-filter effect,phosphorescence probe,chloramphenicol,Mn-doped ZnS quantum dots
更新于2025-09-16 10:30:52
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Electrochemiluminescence resonance energy transfer system between non-toxic SnS2 quantum dots and ultrathin Ag@Au nanosheets for chloramphenicol detection
摘要： Herein, an efficient electrochemiluminescence energy resonance transfer (ECL-RET) system was first applied in an immunosensor for the detection of chloramphenicol (CAP). SnS2 quantum dots (SnS2 QDs) has an extremely narrow electrochemical emission spectrum, which was used as donor. Compared with conventional quantum dots, toxic-element-free SnS2 QDs exhibit superior environmental friendliness and biocompatibility. Ultrathin Ag@Au nanosheets (Ag@Au NSs) was selected as acceptor due to its excellent structure and controllable UV-vis absorption range. Furthermore, ZnO nanoflowers (ZnO NFs) was employed to modify the electrode surface to provide stable luminescent environment and support more SnS2 QDs. Taking these advantages, the absorption spectra of Ag@Au NSs and the ECL emission spectra of SnS2 QDs are highly matched which ensures the occurrence of ECL-RET. When the CAP analyte were absent, Ag@Au NSs was immobilized on the electrode, and its ultrathin thickness effectively shortens the path of ECL-RET to produce the weak ECL intensity. Inversely, CAP analyte would compete with coating antigen for the certain amount of antibody to remove excess Ag@Au NSs and cause relatively high ECL intensity. As a result, the proposed immunosensor performed satisfactory sensitivity with a wide linear range from 0.005 to 1000 ng mL?1 and a low detection limit (1.7 pg mL?1).
关键词： Chloramphenicol,Electrochemiluminescence energy resonance transfer,Ag@Au nanosheets,SnS2 quantum dots,Immunosensor
更新于2025-09-12 10:27:22
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A novel on-chip solution enabling rapid analysis of melamine and chloramphenicol in milk by smartphones
摘要： Ubiquitous food security control is desirable. However, the analysis methods, such as those for milk, are highly based on manual analysis, leading to low efficiency. Thus, we report a multilayer paper-based microfluidic chip transforming chromatic readout to electric signals. First, colloidal gold immunochromatographic assays (GICA) are used to achieve the colorimetric occurrence. Secondly, the test (T) lines and control (C) lines are patterned to encode different EAN-8 barcode. Furthermore, accurate scanning is accomplished by the automatic threshold segmentation. These technologies make the digital determination of melamine (MEL) and chloramphenicol (CAP) by phone readily accessible. Results indicate that the accurate machine-scanning can be assured when MEL and CAP is above 30 ng/mL and 6 ng/mL in milk respectively. The detection time is under 8 min, and the stable storage life is over 90 days. Therefore, this simple chip allows rapid, machine-readable, electric-recordable diagnostic directly from chromatic assays with satisfying stability, specificity and accuracy.
关键词： rapid analysis,smartphone,milk,melamine,on-chip solution,chloramphenicol
更新于2025-09-04 15:30:14