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Simple synthesis of BiOI/ZnO/rGO for efficient photocatalytic degradation of antibiotic chloramphenicol under visible light

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Journal of Environmental Sciences 2023年第12期134卷 65-76页

作者： Zihan Zhu Feng Guo Anming Li Weichao Xu Xuehan Zhang School of Ocean Science and Technology Dalian University of TechnologyPanjin 124221China

BiOI/ZnO/rGO(reduced graphene oxide) composite photocatalyst was fabricated using a simple one-step hydrothermal process and applied to the degradation of antibiotic chloramphenicol(CAP). By tuning the Bi/Zn ratios, the structure and photoelectric properties of the catalyst were investigated and characterized in terms of their morphological, structural, optical and photoelectrochemical properties. The as-synthesized composite photocatalysts are well-crystalline, uniform dispersion and exhibit good photocatalytic properties.The photocatalytic degradation rate of CAP by BiOI/ZnO/rGO composite is 8.1 times and 1.8times that of BiOI and ZnO, respectively. The photocatalytic mechanism studies revealed that the synergistic effect between rGO and BiOI/ZnO can effectively separate photogenerated electron–hole, enhance photocurrents and conductivity, and improve charge carrier densities. Moreover, BiOI/ZnO/rGO possesses good stability and reusability that the degradation efficiency remained above 80% even after 5 recycling. This study reveals that both the introduction of rGO and heterostructure construction between BiOI and ZnO play a crucial role in their photoelectrochemical and photocatalytic properties.

关键词： BiOI/ZnO/rGO(reduced graphene oxide) Photodegradation chloramphenicol Visible light

Point-of-Care Testing of chloramphenicol in Food Production Using Smartphone-Based Electrochemical Detector

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Journal of Analysis and Testing 2023年第1期7卷 33-39页

作者： Changqi Geng Yaqi Huang Bin Li Yueyu Wang Longyi Zhu Yuyan Xu Kejiao Gao Yao Mu Yan Su Shengyuan Deng Ying Wan School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China School of Environmental and Biological Engineering Nanjing University of Science and TechnologyNanjing 210094China School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China

Antibiotic abuse in food processing could threaten human health via either direct pathogen or drug-resistant infection.To curb this situation,it is of vital significance to identify trace level of antibiotics in foodstuffin a point-of-care inspection manner.Here,a smartphone-based electrochemical system was developed for the quantitation of chloramphenicol(CAP).The differential pulse voltammetric reduction of CAP was measured facilely on a piece of gold-deposited screen-printed electrode,which was docked onto a palm-sized detector with remote directives from a mobile APP of Bluetooth handshaking and digital display.Under optimal conditions,the target CAP could be determined in a range from 1 nmol/L to 5μmol/L with a detection limit of 0.25 nmol/L.Further tests on emulate samples demonstrated the miniaturized device could handle the food-screening scenarios with accuracy,convenience and quick response.

关键词： chloramphenicol Electrodeposition Electrochemical detector Screen-printed electrode

Capture-SELEX for chloramphenicol Binding Aptamers for Labeled and Label-Free Fluorescence Sensing

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Environment & Health 2023年第2期1卷 102-109页

作者： Yichen Zhao Albert Zehan Li Juewen Liu Department of Chemistry Waterloo Institute for NanotechnologyWater InstituteUniversity of WaterlooWaterlooOntario N2L 3G1Canada

chloramphenicol(CAP)is a potent antibiotic.Due to its side effects,CAP is currently banned in most countries,but it is still found in many food products and in the environment.Developing aptamer-based biosensors for the detection of CAP has interested many researchers.While both RNA and DNA aptamers were previously reported for CAP,they were all obtained by immobilization of the CAP base,which omitted the two chlorine atoms.In this work,DNA aptamers were selected using the libraryimmobilized method and free unmodified CAP.Three families of aptamers were obtained,and the best one named CAP1 showed a dissociation constant(K_(d))of 9.8μM using isothermal titration calorimetry(ITC).A fluorescent strand-displacement sensor showed a limit of detection(LOD)of 14μM CAP.Thioflavin T(ThT)staining allowed label-free detection of CAP with a LOD of 1μM in buffer,1.8μM in Lake Ontario water,and 3.6μM in a wastewater sample.Comparisons were made with previously reported aptamers,and ITC failed to show binding of a previously reported 80-mer aptamer.Due to the small size and well-defined secondary structures of CAP1,this aptamer will find analytical applications for environmental and food monitoring.

关键词： aptamers biosensors SELEX chloramphenicol antibiotics fluorescence

Optimization of parameters on photocatalytic degradation of chloramphenicol using TiO_2 as photocatalyist by response surface methodology

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Journal of Environmental Sciences 2010年第8期22卷 1281-1289页

作者： Junwei Zhang Dafang Fu Yunda Xu Cuiyun Liu Department of Municipal Engineering Southeast University Nanjing 210096 China Nanjing Engineering Research Centre for Water Treatment and Ecological Restoration Nanjing 210013 China

The experimental design methodology was applied for modeling and optimizing the operation parameters on photocatalytic degradation of chloramphenicol （CAP） using TiO 2 as photocatalyst in a photoreactor. Three experimental parameters （including pH, TiO 2 concentration and CAP initial concentration） were adopted to obtain the preliminary information. The multivariate experimental design was employed to establish a quadratic model as a functional relationship between the degradation rate of CAP and three experimental parameters. The interaction effects and optimal parameters were obtained by using Design Expert software. The optimal values of the operation parameters under the related constraint conditions were found at pH 6.4, TiO 2 concentration of 0.94 g/L and CAP initial concentration of 19.97 mg/L, respectively. The degradation rate of CAP approached 85.97% under optimal conditions. The regression analysis with R 2 value of 0.9519 had a good agreement between the experimental results and the predictive values. In addition, pH and TiO 2 concentration had a significant influence on the degradation rate of CAP.

关键词： chloramphenicol photocatalysis TiO 2 response surface methodology

The impact of different voltage application modes on biodegradation of chloramphenicol and shift of microbial community structure

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Frontiers of Environmental Science & Engineering 2022年第11期16卷 191-202页

作者： Yifan Liu Qiongfang Zhang Ainiwaer Sidike Nuerla Ailijiang Anwar Mamat Guangxiao Zhang Miao Pu Wenhu Cheng Zhengtao Pang Key Laboratory of Oasis Ecology of Education Ministry College of Ecology and EnvironmentXinjiang UniversityUrumqi 830017China Xinjiang Jinghe Observation and Research Station of Temperate Desert Ecosystem Ministry of EducationUrumqi 830017China School of Geographical Sciences Xinjiang UniversityUrumqi 830017China School of Chemical Engineering and Technology Xinjiang UniversityUrumqi 830017China

Exoelectrogenic biofilms have received considerable attention for their ability to enhance electron transfer between contaminants and electrodes in bioelectrochemical systems.In this study,we constructed anaerobic-aerobic-coupled upflow bioelectrochemical reactors(AO-UBERs)with different voltage application modes,voltages and hydraulic retention times(HRTs).In addition,we evaluated their capacity to remove chloramphenicol(CAP).AO-UBER can effectively mineralize CAP and its metabolites through electrical stimulation when an appropriate voltage is applied.The CAP removal efficiencies were~81.1%±6.1%(intermittent voltage application mode)and 75.2%±4.6%(continuous voltage application mode)under 0.5 V supply voltage,which were~21.5%and 15.6%greater than those in the control system without voltage applied,respectively.The removal efficiency is mainly attributed to the anaerobic chamber.High-throughput sequencing combined with catabolic pathway analysis indicated that electrical stimulation selectively enriched Megasphaera,Janthinobacterium,Pseudomonas,Emticicia,Zoogloea,Cloacibacterium and Cetobacterium,which are capable of denitrification,dechlorination and benzene ring cleavage,respectively.This study shows that under the intermittent voltage application mode,AO-UBERs are highly promising for treating antibiotic-contaminated wastewater.

关键词： Electrical stimulation Biodegradation Microbial community chloramphenicol

Reductive degradation of chloramphenicol by Geobacter metallireducens

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Science China(Technological Sciences) 2019年第10期62卷 1688-1694页

作者： XU HengDuo XIAO LeiLei ZHENG ShiLing ZHANG YueChao LI JiaJia LIU FangHua Key Laboratory of Marine Ecology&Environmental Sciences Institute of OceanologyChinese Academy of SciencesQingdao266071China Key Laboratory of Coastal Biology and Utilization Yantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai264003China Laboratory for Marine Biology and Biotechnology Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao266237China University of Chinese Academy of Sciences Beijing100049China

Geobacter metallireducens is known to be capable of removing nitroaromatic compounds via an oxidation mode. However, little attention has been paid to investigate the reductive removal of chlorinated nitroaromatic compounds by G. metallireducens. In this study, G. metallireducens was used to reduce chloramphenicol(CAP), a typical chlorinated nitroaromatic antibiotic. Cyclic voltammograms and chronoamperometry highlighted a higher peak current for CAP reduction by G. metallireducens compared to the control without bacteria. G. metallireducens efficiently reduced CAP(20 mg/L) with acetate as the sole electron donor, and the removal efficiency reached(97.6±4.9)% within 6 d. Aromatic amine(AMCl2), AMCl(dechlorinated AMCl2) and AM(dechlorinated AMCl) were identified as reduction products by liquid chromatography-mass spectrometry. However, the removal efficiency declined to(25.0±3.6)% when the CAP dosage increased to 80 mg/L. Transcriptomic analysis indicated the significant upregulation of genes related to electron transfer, such as pilus assembly protein gene(2.8 folds), NADH-quinone oxidoreductase subunit K2 gene(4.5 folds) and many c-type cytochrome genes such as cytochrome c biogenesis protein Res B(Gmet 2901, 4.6 folds), cytochrome c(Gmet 0335, 4.4 folds) and cytochrome c7(Gmet 2902, 3.4 folds). Furthermore, a gene related to chlorinated contaminant removal(Gmet 1046, 5.4 folds) was also upregulated, possibly resulting in enhanced CAP reduction. This work deepened our knowledge of the bioremediation ability of G. metallireducens with respect to environmental contaminants and provided a potential strategy to treat antibiotics with electrochemically active bacteria.

关键词： chloramphenicol Geobacter metallireducens dechlorination extracellular electron transfer reduction

Enhancing chloramphenicol and trimethoprim in vitro activity by Ocimum sanctum Linn.(Lamiaceae) leaf extract against Salmonella enterica serovar Typhi

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Asian Pacific Journal of Tropical Medicine 2012年第3期5卷 220-224页

作者： Shyamapada Mandal Manisha Deb Mandal Nishith Kumar Pal Department of Microbiology Bacteriology and Serology UnitCalcutta School of Tropical MedicineC.R.AvenueKolkata-700073India Department of Physiology and Biophysics KPC Medical College and HospitalJadavpurKolkata-700032India

Objective:To evaluate the antibacterial activity of Ocimum sanctum(O.sanctum) leaf extract, alone,and in combination with chloramphenicol(C) and trimethoprim(Tm) against Salmonella enterica serovar Typhi(S.typhi).Methods:The antibacterial activity of ethanolic extract of tulsi, 0.sanctum,leaf(TLE:500μg) for 23 S.typhi isolates was determined following agar diffusion. The C(30μg) and Tm(5μg) activity alone and in combination with TLE(250μg) was determined by disk diffusion.The zone diameter of inhibition(ZDI) for the agents was recorded, and growth inhibitory indices(Glls) were calculated.Results:The S.typhi isolates(n=23),which were resistant to both C(ZDI 6 mm) and Tm(ZDI 6 mm),had TLE(500μg) ZDIs 16-24 mm.The ZDIs of C and Tm were increased up to 15-21 mm and 17-23 mm,respectively,when TLE(250μg) was added to the C and Tm discs.The Glls ranged 0.789-1.235 and 0.894-1.352,due to combined activity against S.typhi isolates,of C and TLE and Tm and TLE.respeclivelv.Conclusions:The data suggest that TLE,in combination with C and Tm,had synergistic activity for S.typhi isolates, and hence O.sanclum is potential in combating S.typhi drug resistance,as well promising in the development of non-antibiotic drug for S.typhi infection.

关键词： Antibacterial activity Ocimum sanctum chloramphenicol Trimethoprim Growth inhibitory index Synergy Salmonella enterica serovar Typhi

Separation/Extraction/Detection of chloramphenicol Using Binary Small Molecule Alcohol-Salt Aqueous Two-phase System Coupled with High-performance Liquid Chromatography

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Chemical Research in Chinese Universities 2019年第2期35卷 209-215页

作者： GUO Donggang NI Liang WANG Liang SHAO Li School of the Environment and Safety Engineering School of Chemistry and Chemical EngineeringJiangsu UniversityZhenjiang 212013R R. China Key Laboratory of Preparation and Application of Environmental Friendly Materials Jilin Normal UniversityMinistry of EducationChangchun 130103P. RChina

A green and sensitive sample separation and purification method coupled with high-perfomiance liquid chromatography(HPLC)was developed for the analysis of chioramphenicol(CAP).One element small molecule alcohol-salt aqueous two-phase system(ATPS)can't effectively adjust the polarity of the system,but binary small molecule alcohol-salt ATPS can adjust the polarity and improve the extraction efficiency of antibiotics.A binary aqueous two-phase system based on 1-propanol+2-propanol and NaH2PO4 system was formed and applied to the separation and purification of trace CAP in real samples.The influence factors on partition behaviors of CAP were discussed,including the types and mass of salts,the volume ratio of alcohol,the pH,temperature and the standing time.The optimal condition was found at pH=5.0,2.5 g of NaH2PO4,3.0 mL of 1-propanol and 2-propanol(volume ratio 1:1)and 30℃by using response surface methodology.Under this optimal condition,the extraction efficiency of CAP reached 98.91%,and partition coefficient of CAP was 17.31.

关键词： Binary small molecule alcohol aqueous two-phase system Partition behavior chloramphenicol Extraction efficiency

Handheld Aptasensor for Sandwiched Detection of chloramphenicol

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Chemical Research in Chinese Universities 2020年第2期36卷 291-295页

作者： YU Mintong XIA Tian BAI Wanchen JI jinyu WANG Huan HUANG Yaqi DENG Shengyuan MA Kefeng SU Yan WAN Ying School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094P.R.China Key Laboratory of New Membrane Materials Ministry of Industry and Information TechnologySchool of Environmental and Biological EngineeringNanjing University of Science and Technology/Nanjing 210094R R.China

chloramphenicol(CAP)is an antifungal agent approved for use in aquarium.However,CAP residue imparts serious adverse effect on human health as well as the ecology.Thus,keeping track of CAP in aquatic products and its environmental metabolites are of great importance.Herein,we developed a novel and neat electrochemical aptasensor for the detection of simulated CAP residual in a sandwich fashion.The screen-printed carbon electrode was employed as the sensing platform and electrodeposited with peculiar nanogolds to enhance the electrochemical performance.For the specific recognition of such small target,a pair of chloramphenicol-binding aptamers,the primary Aptl and the secondary Apt2,were tailored as an artificial single-chained antibody couple,of which the thi-olated Aptl stood on the coated working substrate to capture the analyte,while the biotinylated Apt2 rallied the signal output.In the presence of CAP,Aptl at the lower place cooperated with the upper Apt2 pinched CAP together.After that,the reporter avidin-conjugated horseradish peroxidase associated atop the mounted biotin labels,resulting in an electrocatalytic amplification.In whole,this modular biosensing construction would set a paradigm not just for practicable checkpoint quarantine or point-of-care testing,but potentially adaptable for technological fusion with“Internet Plus”and“Internet of Things”.

关键词： chloramphenicol Screen-printed carbon electrode Electrochemical aptasensor Electrochemical deposi tion Ufkimm