作者机构：
[Hu, Xinjiang; Zhao, Yunlin; Xu, Zhenggang; He, Tianpei; Wu, Yaohui; Zhao, YL; Wu, YH; Liu, Wen; Wang, Yonghong; Chen, Xiaoyong] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.;[Ning, Ge] Hunan Univ Chinese Med, Int Educ Inst, Changsha 410208, Peoples R China.;[Chen, Xiaoyong] Governors State Univ, Coll Arts & Sci, University Pk, PA 60484 USA.
通讯机构：
[Zhao, YL ; Wu, YH] C;Cent South Univ Forestry & Technol, Coll Life Sci & Technol, Changsha 410004, Peoples R China.
摘要：
<jats:title>Abstract</jats:title><jats:p>Norfloxacin (NOF) is an environmentally harmful and ubiquitous aquatic pollutant with extensive production and application. In this study, a novel composition named carbon-based composite photocatalytic material of zinc oxide and zinc sulphide (ZnO/ZnS@BC) was successfully obtained by the impregnation-roasting method to remove NOF under UV-light. Scanning electron microscopy, X-ray photoelectron spectroscopy, transmission electron microscopy and energy dispersive spectrometer characterised the composition. ZnO/ZnS was successfully decorated on the surface of biochar (BC). The pH, the ZnSO<jats:sub>4</jats:sub>/PS ratio, and ions and quenchers, were investigated. High removal efficiency was obtained with a pH of 7 and a ZnSO<jats:sub>4</jats:sub>/PS ratio of 1:1, and the removal ratio of NOF reached 95% within three hours; the adsorption and degradation ratios reached 46% and 49%, respectively. Fe<jats:sup>2+</jats:sup> promoted the degradation of NOF, whereas other ions inhibited it, with NO<jats:sub>3</jats:sub><jats:sup>−</jats:sup> showing the strongest inhibitory effect. Three reactive species (tert-butanol, quinone, and ammonium oxala) were identified in the catalytic system. The decreasing order of the contribution of each reactive species was: O<jats:sub>2</jats:sub><jats:sup>−</jats:sup> > ·OH<jats:sup>−</jats:sup> > h<jats:sup>+</jats:sup>. Additionally, a recycling experiment demonstrated the stability of the catalyst; the catalytic degradation ratio of NOF reached 78% after five successive runs. Therefore, ZnO/ZnS@BC possessed strong adsorption capacity and high ultraviolet photocatalysis ability.</jats:p>
作者机构：
[Liu, Gaoqiang; Chen, Zhifen; He, Tianpei; Wu, Yaohui; Jiang, Chenyang; Wu, YH; Wang, Yonghong; Chen, Xiaoyong] Cent South Univ Forestry & Technol, Hunan Prov Key Lab Forestry Biotechnol, Changsha, Peoples R China.;[Zhao, Yunlin; Xu, Zhenggang; Wu, Yaohui; Wu, YH] Cent South Univ Forestry & Technol, Hunan Res Ctr Engn Technol Utilizat Environm & Re, Changsha, Peoples R China.;[Xu, Zhenggang] Hunan City Univ, Hunan Urban & Rural Ecol Planning & Restorat Engn, Yiyang, Hunan, Peoples R China.;[Ning, Ge] Hunan Univ Chinese Med, Int Educ Inst, Changsha, Peoples R China.
通讯机构：
[Wu, YH ] C;Cent South Univ Forestry & Technol, Hunan Prov Key Lab Forestry Biotechnol, Changsha, Peoples R China.;Cent South Univ Forestry & Technol, Hunan Res Ctr Engn Technol Utilizat Environm & Re, Changsha, Peoples R China.
摘要：
In the present work, a series of magnetically separable Fe3O4/g-C3N4/MoO(3)nanocomposite catalysts were prepared. The as-prepared catalysts were characterized by XRD, EDX, TEM, FT-IR, UV-Vis DRS, TGA, PL, BET and VSM. The photocatalytic activity of photocatalytic materials was evaluated by catalytic degradation of tetracycline solution under visible light irradiation. Furthermore, the influences of weight percent of MoO(3)and scavengers of the reactive species on the degradation activity were investigated. The results showed that the Fe3O4/g-C3N4/MoO3(30%) nanocomposites exhibited highest removal ability for TC, 94% TC was removed during the treatment. Photocatalytic activity of Fe3O4/g-C3N4/MoO3(30%) was about 6.9, 5, and 19.9-fold higher than those of the MoO3, g-C3N4, and Fe3O4/g-C(3)N(4)samples, respectively. The excellent photocatalytic performance was mainly attributed to the Z-scheme structure formed between MoO(3)and g-C3N4, which enhanced the efficient separation of the electron-hole and sufficient utilization charge carriers for generating active radials. The highly improved activity was also partially beneficial from the increase in adsorption of the photocatalysts in visible range due to the combinaion of Fe3O4. Superoxide ions (center dot O-2(-)) was the primary reactive species for the photocatalytic degradation of TC, as degradation rate were decreased to 6% in solution containing benzoquinone (BQ). Data indicate that the novel Fe3O4/g-C3N4/MoO(3)was favorable for the degradation of high concentrations of tetracycline in water.
摘要：
Smartly coupling exonuclease-induced target recycling signal amplifications with beta-cyclodextrin host-guest recognition, a novel "signal-on" aptamer sensor for sensitive determination of ochratoxin A (OTA) was proposed for the first time. Firstly, the formation of double-strand DNA (dsDNA) was occurred by hybridizing OTA aptamer with its complementary DNA (cDNA) and as the probe DNA the cDNA at its 3' terminal was labeled with methylene blue (MB). Next, when OTA was present, the aptamer tended to form aptamer-OTA complex with conformation of G-quadruplex instead of aptamer-cDNA duplex, leading to thus the probe DNA separating from dsDNA complex. Then the RecJf exonuclease was added, demolishing partially G-quadruplex structure and releasing a certain number of OTA. Sequentially, those released OTA would continue to react with the rest of aptamer in dsDNA, drawn into development of a new round of G-quadruplex complex, where the target cycling was realized. Meanwhile, as a signal molecule, MB modified on cDNA was liberated along with the cDNA being digested into monoucleotides by RecJf exonuclease, capable of diffusing onto the electrode surface due to host-guest recognition with beta-cyclodextrin, whereupon the signal was enriched and yielded. In this way, cycles of target with continuous output of signal indicators were undergone, in which the detection of target was in return fulfilled with signal amplification owing to the joint endeavor of exonuclease and beta-cyclodextrin. Under the optimal conditions, the raising signal maintained a linear relation with the logarithm of the target concentrations ranging from 10pg/mL to 10.0ng/mL and the detection limit reached as low as 3pg/mL. This brand-new strategy was simple and low-cost but satisfactory in terms of detection limit, range and sensitivity, in all possibility to be applied extensively for diverse targets detection by easily alternating the corresponding aptamers.
