Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not mee...Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not meet the requirements of analysis for time-sensitive samples and/or complicated environmental samples. Since energy-dispersive X-ray spectrometry(EDS) can be used to simultaneously detect multiple elements in a sample, including sulfur, with minimal sample treatment, this technology was applied to detect sulfur-oxidizing bacteria using their high sulfur content within the cell. This article describes the application of scanning electron microscopy imaging coupled with EDS mapping for quick detection of sulfur oxidizers in contaminated environmental water samples, with minimal sample handling. Scanning electron microscopy imaging revealed the existence of dense granules within the bacterial cells, while EDS identified large amounts of sulfur within them. EDS mapping localized the sulfur to these granules. Subsequent 16S rRNA gene sequencing showed that the bacteria detected in our samples belonged to the genus Chromatium, which are sulfur oxidizers. Thus, EDS mapping made it possible to identify sulfur oxidizers in environmental samples based on localized sulfur within their cells, within a short time(within 24 h of sampling). This technique has wide ranging applications for detection of sulfur bacteria in environmental water samples.展开更多
Acetonitrile inorganic salt aqueous two-phase extraction method was established for the determination of triazine herbicides(simeton,cyanazine,desmetryn,terbumeton,terbuthylazine and dimethametryn)in environmental wat...Acetonitrile inorganic salt aqueous two-phase extraction method was established for the determination of triazine herbicides(simeton,cyanazine,desmetryn,terbumeton,terbuthylazine and dimethametryn)in environmental water samples by high-performance liquid chromatography(HPLC).The extraction solvents types and volume of acetonitrile,the inorganic salt types and amount of(NH_(4))_(2)SO_(4),extraction time and pH of sample solution were optimized by single-factor experiment and central composite design.Under the optimum extraction conditions,all linear ranges were obtained with coefficients of determination(r)≥0.9993.The limits of detection for this proposed method were in the range of 0.16-0.28μg/L for six triazine herbicides.The developed method has been successfully applied to the analysis of target triazine herbicides from lake,canal and moat in real-world water samples.The recoveries of target analytes were in the range from 87.0 to 110.9%and the relative standard deviation was lower than 7.3%.展开更多
Facile and ultrasensitive detection of Pb^(2+)in water for remote or resource-limited environments remains challenging.DNAzyme-based colorimetric nanobiosensors have been extensively studied to regulate the assembly o...Facile and ultrasensitive detection of Pb^(2+)in water for remote or resource-limited environments remains challenging.DNAzyme-based colorimetric nanobiosensors have been extensively studied to regulate the assembly of functionalized gold nanoparticles(AuNPs).However,these nanobiosensors have been criticized for their low sensitivity owing to the difficulty of dissociating DNAzyme embedded in AuNP aggregates.To address this issue,we rationally designed a DNAzyme by introducing an adenine-cytosine(A-C)mismatch to strengthen the disassembly of DNAzyme-linked nanostructures.As proof of concept,a“turn on”colorimetric nanobiosensor integrated with mismatched DNAzyme and functionalized AuNPs was first developed for Pb^(2+)detection.Under the optimal detection conditions,the obtained typical calibration curve shows a detection limit of 8.6 nmol/L,with an approximately 11-fold sensitivity improvement in Pb^(2+)detection compared with unmismatched DNAzyme,and a linear response range from 10 to 300 nmol/L.This nanobiosensor demonstrated robust selectivity and satisfactory recovery rates between 86.5%and 106.4%for Pb^(2+)in spiked environmental water samples.Additionally,the detection process is user-friendly and can be completed within 30 min,requiring only a simple water sample addition step.Considering the extensive applications of DNAzyme in conjunction with nanoparticles,this study provides a valuable reference for designing other DNAzyme-powered nanoparticle assemblies in biosensing systems.展开更多
The paper describes a novel method for copper preconcentration using microcrystalline triphenylmethane loaded with malachite green prior to the determination by the flame atomic absorption spectrometry （FAAS）. Under...The paper describes a novel method for copper preconcentration using microcrystalline triphenylmethane loaded with malachite green prior to the determination by the flame atomic absorption spectrometry （FAAS）. Under the optimum conditions, Cu（Ⅱ） can be totally adsorbed on the surface of microcrystalline triphenylmethane, and completely separated from Pb（Ⅱ）, Cd（Ⅱ）, Co（Ⅱ）, Cr（Ⅲ）, Ni（Ⅱ）, Mn（Ⅱ）, Fe（Ⅲ） and Al（Ⅲ） by controlling acidity. The preconcentration factor of this proposed method is 200. The recovery is in a range of 97.5%-105%. The relative standard deviation （RSD） is not beyond 3.0%. The proposed method has been successfully applied to the determination of trace copper in various water samples with satisfactory results.展开更多
基金Supported by the Basic Scientific Fund for National Public Research Institutes of China(Nos.GY02-2011T10,2015P07)the Qingdao Talent Program(No.13-CX-20)+1 种基金the National Natural Science Foundation of China(Nos.31100567,41176061)the National Natural Science Foundation for Creative Groups(No.41521064)
文摘Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not meet the requirements of analysis for time-sensitive samples and/or complicated environmental samples. Since energy-dispersive X-ray spectrometry(EDS) can be used to simultaneously detect multiple elements in a sample, including sulfur, with minimal sample treatment, this technology was applied to detect sulfur-oxidizing bacteria using their high sulfur content within the cell. This article describes the application of scanning electron microscopy imaging coupled with EDS mapping for quick detection of sulfur oxidizers in contaminated environmental water samples, with minimal sample handling. Scanning electron microscopy imaging revealed the existence of dense granules within the bacterial cells, while EDS identified large amounts of sulfur within them. EDS mapping localized the sulfur to these granules. Subsequent 16S rRNA gene sequencing showed that the bacteria detected in our samples belonged to the genus Chromatium, which are sulfur oxidizers. Thus, EDS mapping made it possible to identify sulfur oxidizers in environmental samples based on localized sulfur within their cells, within a short time(within 24 h of sampling). This technique has wide ranging applications for detection of sulfur bacteria in environmental water samples.
基金the major project of Natural Science Foundation of Jiangsu Higher Education Institutions of China(no:15KJA610003)Natural Science Foundation of Jiangsu Province(no.BK20160359)Natural Science and Technology Program on Water Pollution Control and Treatment(2017ZX07205-2).
文摘Acetonitrile inorganic salt aqueous two-phase extraction method was established for the determination of triazine herbicides(simeton,cyanazine,desmetryn,terbumeton,terbuthylazine and dimethametryn)in environmental water samples by high-performance liquid chromatography(HPLC).The extraction solvents types and volume of acetonitrile,the inorganic salt types and amount of(NH_(4))_(2)SO_(4),extraction time and pH of sample solution were optimized by single-factor experiment and central composite design.Under the optimum extraction conditions,all linear ranges were obtained with coefficients of determination(r)≥0.9993.The limits of detection for this proposed method were in the range of 0.16-0.28μg/L for six triazine herbicides.The developed method has been successfully applied to the analysis of target triazine herbicides from lake,canal and moat in real-world water samples.The recoveries of target analytes were in the range from 87.0 to 110.9%and the relative standard deviation was lower than 7.3%.
基金supported by the Basic Research Project of Shanxi Province,China(202203021222086)the start-up foundation of Taiyuan University of Technology,China(RY2400000583).
文摘Facile and ultrasensitive detection of Pb^(2+)in water for remote or resource-limited environments remains challenging.DNAzyme-based colorimetric nanobiosensors have been extensively studied to regulate the assembly of functionalized gold nanoparticles(AuNPs).However,these nanobiosensors have been criticized for their low sensitivity owing to the difficulty of dissociating DNAzyme embedded in AuNP aggregates.To address this issue,we rationally designed a DNAzyme by introducing an adenine-cytosine(A-C)mismatch to strengthen the disassembly of DNAzyme-linked nanostructures.As proof of concept,a“turn on”colorimetric nanobiosensor integrated with mismatched DNAzyme and functionalized AuNPs was first developed for Pb^(2+)detection.Under the optimal detection conditions,the obtained typical calibration curve shows a detection limit of 8.6 nmol/L,with an approximately 11-fold sensitivity improvement in Pb^(2+)detection compared with unmismatched DNAzyme,and a linear response range from 10 to 300 nmol/L.This nanobiosensor demonstrated robust selectivity and satisfactory recovery rates between 86.5%and 106.4%for Pb^(2+)in spiked environmental water samples.Additionally,the detection process is user-friendly and can be completed within 30 min,requiring only a simple water sample addition step.Considering the extensive applications of DNAzyme in conjunction with nanoparticles,this study provides a valuable reference for designing other DNAzyme-powered nanoparticle assemblies in biosensing systems.
基金Project supported by the Natural Science Foundation of Henan Province （No. 0511020500） and Innovation Project Foundation of University in Henan Province （No. 2001-513）.
文摘The paper describes a novel method for copper preconcentration using microcrystalline triphenylmethane loaded with malachite green prior to the determination by the flame atomic absorption spectrometry （FAAS）. Under the optimum conditions, Cu（Ⅱ） can be totally adsorbed on the surface of microcrystalline triphenylmethane, and completely separated from Pb（Ⅱ）, Cd（Ⅱ）, Co（Ⅱ）, Cr（Ⅲ）, Ni（Ⅱ）, Mn（Ⅱ）, Fe（Ⅲ） and Al（Ⅲ） by controlling acidity. The preconcentration factor of this proposed method is 200. The recovery is in a range of 97.5%-105%. The relative standard deviation （RSD） is not beyond 3.0%. The proposed method has been successfully applied to the determination of trace copper in various water samples with satisfactory results.
