Zhifeng Cai,Yixuan Zhang,Manlin Zhao,Jinjia Bao,Ling Lv,Haoyang Li
Copper nanoclusters (FA@CuNCs) emitting blue fluorescence were successfully developed via a one-pot technique. In this method, the copper chloride, folic acid and hydrazine hydrate were applied as a precursor, protective agent and reducing agent, respectively. The absorption, fluorescence excitation and emission spectra of FA@CuNCs were carried out by using ultraviolet–visible and fluorescence spectrometry, respectively. The morphology, particle size, functional groups, oxidation states of elements of FA@CuNCs were discussed via using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The stability of FA@CuNCs was studied under various conditions, such as storage time at 25 ℃, ultraviolet radiation time, sodium chloride solutione and pH. The FA@CuNCs displayed blue fluorescence under the excitation wavelength of 361 nm, and the fluorescence quantum yield was 7.45 %. As a result of the inner filter effect, the alizarin red could significantly weaken the blue fluorescence of FA@CuNCs. Thus, the as-prepared FA@CuNCs could be utilized as fluorescence nanosensors for the trace determination of alizarin red. This platform suggested an excellent linear range for alizarin red varying from 0.5 to 200 μM with a fitting coefficient of 0.9955. The detection limit was calculated to be 0.064 μM in the light of the 3b/k (b and k refer to the standard deviation and slope of fitted curve, respectively). Furthermore, the as-developed FA@CuNCs could be used to detect the alizarin red in real samples and for the sensing of temperature.
Azo dyes are huge social and environmental hazards. Selective fungi are potential degraders for azo dyes and are of great significance to cleaning up and bioremediation. In this study, a salt-tolerant yeast strain GG with the ability to aerobically degrade and detoxify various azo dyes was isolated and identified as Galactomyces geotrichum . The optimal growth and decolorization parameters of strain GG were 0.1 g/L of yeast extract, 2.0 g/L of glucose, 0.4 g/L of ammonium sulfate , ≤ 40 g/L of NaCl, and pH values of 7.0–8.0. Under the optimal condition more than 92% of 100 mg/L of Acid Scarlet GR could be decolorized within 10 h by degradation, which was further confirmed by Fourier transform infrared spectroscopy . In addition, enzymatic analysis showed that the reductase NADH-DCIP and two oxidoreductases lignin peroxidase and laccase played the key roles in the degradation of Acid Scarlet GR, and the decolorization metabolites of Acid Scarlet GR exhibited much less toxicity than the parent dye by phytotoxicity assessment. The results improved the knowledge of azo-dye-decolorizing G. geotrichum species and provided efficient fungal resource for treatment of industrial wastewater containing azo dyes and salts.
危险品化学品经营许可证（带存储）