A method was established for detecting the content of nitrofurazone (NFZ) by fluorescence quenching of N-Acetyl-L-Cysteine (NAC) coated cadmium telluride quantum dots (CdTe QDs). By means of transmission electron microscopy (TEM) and multispectral methods such as fluorescence and ultraviolet visible spectra (UV-vis), the synthesized CdTe QDs were characterized. The quantum yield (φ) of CdTe QDs was measured as 0.33 by reference method. The CdTe QDs had a better stability, the RSD of fluorescence intensity was 1.51% in three months. NFZ quenching the emission light of CdTe QDs was observed. The analyses of Stern-Volmer and time-resolved fluorescence suggested the quenching was static. The binding constants (K) between NFZ and CdTe QDs were 1.14 × 10 (293 K), 0.74 × 10 (303 K) and 0.51 × 10 (313 K) L mol. The hydrogen bond or van der Waals force was the dominated binding force between NFZ and CdTe QDs. The interaction was further characterized by UV-vis absorption as well as Fourier transform infrared spectra (FT-IR). Using fluorescence quenching effect, a quantitative determination of NFZ was carried out. The optimal experimental conditions were studied and determined as following: pH was 7 and contact time was 10 min. The effects of reagent addition sequence, temperature and the foreign substances including some metals (Mg; Zn; Ca; K; Cu), glucose, bovine serum albumin (BSA) and furazolidone on the determination were studied. There was a high correlation between the concentration of NFZ (0.40 - 39.63 μg mL) and F/F with the standard curve F/F = 0.0262c + 0.9910 (r = 0.9994). The detection limit (LOD) reached 0.04 μg mL (3S/S). The contents of NFZ in beef and bacteriostatic liquid were detected. The recovery of NFZ was 95.13% - 103.03% and RSD was 0.66% - 1.37% (n = 5).
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http://dx.doi.org/10.1016/j.saa.2023.122709 | DOI Listing |
J Fluoresc
January 2025
Scientific and Technological Researches Application and Research Center, Duzce University, Duzce, Türkiye.
This study highlights the aqueous synthesis of CdTe/ZnS core/shell quantum dots (QDs) and their application as fluorescence sensors for detecting critical metabolites, including folic acid, glucose, and vitamin C, in real biological samples. The synthesized QDs exhibit excellent quantum efficiency, stability, and biocompatibility, enhanced by mercaptopropionic acid (MPA) ligands, enabling eco-friendly and accurate sensing. Detection limits of 0.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Microbiology (Biocenter 1, Viikinkaari 9), Faculty of Agriculture and Forestry, University of Helsinki, Finland.
The white rot fungus was investigated for its ability to decolorize the reactive textile dye Reactive Black 5 (RB5) that was co-exposed to CdCl and quantum dots (QDs) consisting of a CdTe core capped with two different hydrophilic organic ligands (NAC and MPA). Without co-exposure, completely decolorizes RB5 within 9 days. The highest inhibitory effect was found for soluble CdCl with an EC of 583 μg l, followed by MPA-QDs (10,628 μg l) and NAC-QDs (17,575 μg l).
View Article and Find Full Text PDFAnal Chem
January 2025
School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng 224051, P. R. China.
DNAzyme-based cascade networks are effective tools to achieve ultrasensitive detection of low-abundance miRNAs. However, their designs are complicated and costly, and the operation is time-consuming. Herein, a novel simple noncascade DNAzyme network is designed and its amplification effect is comparable to or even better than many cascading ones.
View Article and Find Full Text PDFAnal Bioanal Chem
January 2025
School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, 510006, China.
Although fluorescence analysis methods are widely used in pesticide residue detection, improving their sensitivity and selectivity remains a challenge. This paper presents a novel ratio fluorescence sensor based on the molecular imprinting polymers (MIPs) and metal-enhanced fluorescence for visual detection of dicamba (DIC). Calcium fluoride (CaF) quantum dots (QDs) were immobilized on the surface of Ag@MIPs, resulting in a blue fluorescence response signal (Ag@MIPs-CaF).
View Article and Find Full Text PDFMolecules
December 2024
State Key Laboratory of Molecular Engineering of Polymers, Laboratory of Advanced Materials, Shanghai Key Lab of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, Shanghai 200438, China.
With the development and improvement of analysis and detection systems, low-toxicity and harmless detection systems have received much attention, especially in the field of food detection. In this paper, a low-toxicity dual-emission molecularly imprinted fluorescence sensor (CdTe QDs@SiO/N-CDs@MIPs) was successfully designed for highly selective recognition and visual detection of tetracycline (TC) in food samples. Specifically, the non-toxic blue-emission N-doped carbon dots (N-CDs) with high luminous performance acted as the response signals to contact TC via the covalent bond between amino and carboxyl groups.
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