Multi-walled carbon nanotubes （MWCNTs） were coated with ZnO by a hydrothermal method. The resulting nanocomposites were mixed with the Nation solution to form a composite matrix for the fabrication of hemoglobin （H...Multi-walled carbon nanotubes （MWCNTs） were coated with ZnO by a hydrothermal method. The resulting nanocomposites were mixed with the Nation solution to form a composite matrix for the fabrication of hemoglobin （Hb） biosensor. To prevent the leak of Hb molecules of the biosensor, silica sol-gel film was coated on the surface of the Hb/ZnO-MWCNTs/Nafion electrode. The silica sol-gel/Hb/ZnO-MWCNTs/Nafion film exhibited a pair of well-defined, quasi-reversible redox peaks. This biosensor showed excellent electrocataiytic activity to H2O2. The sensitivity and apparent Michaelis-Menten constant of this Hb biosensor to H2O2 were 1.31 A/（M cm^2） and 82.8 μmol/L, respectively, which indicated that Hb had high affinity to H2O2.展开更多
Microbiologically influenced corrosion （MIC） is a major cause of corrosion damages, facility failures, and financial losses, making MIC an important research topic. Due to complex microbiological activities and a la...Microbiologically influenced corrosion （MIC） is a major cause of corrosion damages, facility failures, and financial losses, making MIC an important research topic. Due to complex microbiological activities and a lack of deep understanding of the interactions between biofilms and metal surfaces, MIC occurrences and mechanisms are difficult to predict and interpret. Many theories and mechanisms have been pro- posed to explain MIC. In this review, the mechanisms of MIC are discussed using hioenergetics, microbial respiration types, and biofilm extracellular electron transfer （EET）. Two main MIC types, namely EET-MIC and metabolite MIC （M-ME）, are discussed. This brief review provides a state of the art insight into MIC mechanisms and it helps the diagnosis and prediction of occurrences of MIC under anaerobic conditions in the oil and gas industry.展开更多
A novel mesoporous carbon/whisker-like carbon (MCWC) composite was used for the immobilization of laccase (Lac) and its bioelectrochemical behaviors were studied.It was confirmed by XPS that Lac was strongly adsorbed ...A novel mesoporous carbon/whisker-like carbon (MCWC) composite was used for the immobilization of laccase (Lac) and its bioelectrochemical behaviors were studied.It was confirmed by XPS that Lac was strongly adsorbed on the surface of the MCWC composite.The cyclic voltammetric results showed that the immobilized Lac underwent a direct quasi-reversible electrochemical reaction.The value of the electron transfer rate constant ks was estimated to be 0.770 s-1,indicating a reasonably fast electron transfer between the immobilized Lac and the underlying electrode.The surface concentration (I-) of Lac was estimated to be 2.730 × 10-12 mol/cm2.Further experimental results showed that the immobilized Lac displayed an appreciable electrocatalytic activity to the electrochemical reduction of O2.These properties could be attributed to the particular structure of loosely packed nanometer-scale carbon whiskers and the existence of a large amount of oxygen-containing groups.The immo- bilization method and the novel carrier (MCWC) may find new applications in fabricating the biocatalysts for biofuel cells.展开更多
Carbon fibers(CFs)demonstrate a range of excellent properties including(but not limited to)microscale diameter,high hardness,high strength,light weight,high chemical resistance,and high temperature resistance.Therefor...Carbon fibers(CFs)demonstrate a range of excellent properties including(but not limited to)microscale diameter,high hardness,high strength,light weight,high chemical resistance,and high temperature resistance.Therefore,it is necessary to summarize the application market of CFs.CFs with good physical and chemical properties stand out among many materials.It is believed that highly fibrotic CFs will play a crucial role.This review first introduces the precursors of CFs,such as polyacrylonitrile,bitumen,and lignin.Then this review introduces CFs used in BESs,such as electrode materials and modification strategies of MFC,MEC,MDC,and other cells in a large space.Then,CFs in biosensors including enzyme sensor,DNA sensor,immune sensor and implantable sensor are summarized.Finally,we discuss briefly the challenges and research directions of CFs application in BESs,biosensors and more fields.展开更多
Monodisperse TiO2 nanoparticles and urchin-like hierarchical TiO2 nanospheres assembled with ultrathin quantum nanowires(about 2 nm)have been synthesized by a simple template-free wet chemical method.The morphology,st...Monodisperse TiO2 nanoparticles and urchin-like hierarchical TiO2 nanospheres assembled with ultrathin quantum nanowires(about 2 nm)have been synthesized by a simple template-free wet chemical method.The morphology,structure,and crystallinity of the TiO2 nanomaterials were investigated by field emission scanning electron microscopy(FESEM),X-ray diffraction(XRD),and high resolution transmission electron microscopy(HRTEM).Electrochemical measurements with the hierarchically nanostructured TiO2 nanospheres as an electrode showed much better reversibility for direct electrochemistry of cytochrome c(cyt c)and much higher sensitivity than for an electrode composed of the monodisperse TiO2 nanoparticles.The excellent performance of the hierarchical TiO2 nanospheres may result from a quantum size effect,and their favorable nanostructure(with the presence of an abundance of both uniform macropores and mesopores),excellent structural stability and high specific surface area.The relative ionic strength had significant effect on the direct electrochemistry.Very high ionic strengths relative to cyt c concentration(I/c)induced a conformational change of cyt c on the nanostructure-coated electrode,from the native state to a partially unfolded one in 25 mmol/L phosphate buffer solution(pH 6.8).展开更多
Using bioelectrochemical systems(BESs)to provide electrochemically generated hydrogen is a promising technology to provide electron donors for reductive dechlorination by organohalide-respiring bacteria.In this study,...Using bioelectrochemical systems(BESs)to provide electrochemically generated hydrogen is a promising technology to provide electron donors for reductive dechlorination by organohalide-respiring bacteria.In this study,we inoculated two syntrophic dechlorinating cultures containing Dehalobacter and Dehalobacterium to sequentially transform chloroform(CF)to acetate in a BES using a graphite fiber brush as the electrode.In this co-culture,Dehalobacter transformed CF to stoichiometric amounts of dichloromethane(DCM)via organohalide respiration,whereas the Dehalobacterium-containing culture converted DCM to acetate via fermentation.BES were initially inoculated with Dehalobacter,and sequential cathodic potentials of-0.6,-0.7,and -0.8 V were poised after consuming three CF doses(500 μM)per each potential during a time-span of 83 days.At the end of this period,the accumulated DCM was degraded in the following seven days after the inoculation of Dehalobacterium.At this point,four consecutive amendments of CF at increasing concentrations of 200,400,600,and 800 μM were sequentially transformed by the combined degradation activity of Dehalobacter and Dehalobacterium.The Dehalobacter 16S rRNA gene copies increased four orders of magnitude during the whole period.The coulombic efficiencies associated with the degradation of CF reached values>60% at a cathodic potential of -0.8 V when the degradation rate of CF achieved the highest values.This study shows the advantages of combining syntrophic bacteria to fully detoxify chlorinated compounds in BESs and further expands the use of this technology for treating water bodies impacted with pollutants.展开更多
The investigation of interactions of DNA with other molecules, whose results may be helpful to understanding some diseases and the mechanisms, by which some medicines (especially antitumor drugs) act, is of great impo...The investigation of interactions of DNA with other molecules, whose results may be helpful to understanding some diseases and the mechanisms, by which some medicines (especially antitumor drugs) act, is of great importance in elucidating the structures of DNA and their function. Many studies of interactions of DNA with porphyrins have展开更多
The electrochemical reduction behavior of bilirubin (BR) at platinum electrode in DMF was investigated by cyclic voltammetry, in situ electron spin resonance spectroscopy and in situ rapid scanning thin layer spectroe...The electrochemical reduction behavior of bilirubin (BR) at platinum electrode in DMF was investigated by cyclic voltammetry, in situ electron spin resonance spectroscopy and in situ rapid scanning thin layer spectroelectrochemistry. Experimental results revealed that the reduction of BR firstly undergoes an ECE process: GRAPHICS The generated (BR)(2)(3-). can be re-oxidized to BR and then to purpurin (Pu) by a series of oxidation processes: GRAPHICS However, the re-reduction reactions of Pu are not the reverse processes. The different reduction mechanisms are discussed in detail.展开更多
Several aspects of the application of silver electrode to the electrochemical studies of hemoglobin have been discussed in this paper. The silver electrode could not only be used directly as the electrode for the elec...Several aspects of the application of silver electrode to the electrochemical studies of hemoglobin have been discussed in this paper. The silver electrode could not only be used directly as the electrode for the electrochemical studies of hemoglobin, but also react with phenothiazine and benzimidazole to give stable and useful mediator-coated electrodes. In addition, the silver electrode could help sodium dodecyl sulfate to give full play to its promoting effect on the protein.展开更多
文摘Multi-walled carbon nanotubes （MWCNTs） were coated with ZnO by a hydrothermal method. The resulting nanocomposites were mixed with the Nation solution to form a composite matrix for the fabrication of hemoglobin （Hb） biosensor. To prevent the leak of Hb molecules of the biosensor, silica sol-gel film was coated on the surface of the Hb/ZnO-MWCNTs/Nafion electrode. The silica sol-gel/Hb/ZnO-MWCNTs/Nafion film exhibited a pair of well-defined, quasi-reversible redox peaks. This biosensor showed excellent electrocataiytic activity to H2O2. The sensitivity and apparent Michaelis-Menten constant of this Hb biosensor to H2O2 were 1.31 A/（M cm^2） and 82.8 μmol/L, respectively, which indicated that Hb had high affinity to H2O2.
基金supported by Science Foundation of China University of Petroleum,Beijing(Nos.2462017YJRC038 and 2462018BJC005)supported by the National Natural Science Foundation of China(Grant U1660118)+1 种基金the National Basic Research Program of China(973 Program,No.2014CB643300)the National Environmental Corrosion Platform(NECP)
文摘Microbiologically influenced corrosion （MIC） is a major cause of corrosion damages, facility failures, and financial losses, making MIC an important research topic. Due to complex microbiological activities and a lack of deep understanding of the interactions between biofilms and metal surfaces, MIC occurrences and mechanisms are difficult to predict and interpret. Many theories and mechanisms have been pro- posed to explain MIC. In this review, the mechanisms of MIC are discussed using hioenergetics, microbial respiration types, and biofilm extracellular electron transfer （EET）. Two main MIC types, namely EET-MIC and metabolite MIC （M-ME）, are discussed. This brief review provides a state of the art insight into MIC mechanisms and it helps the diagnosis and prediction of occurrences of MIC under anaerobic conditions in the oil and gas industry.
文摘A novel mesoporous carbon/whisker-like carbon (MCWC) composite was used for the immobilization of laccase (Lac) and its bioelectrochemical behaviors were studied.It was confirmed by XPS that Lac was strongly adsorbed on the surface of the MCWC composite.The cyclic voltammetric results showed that the immobilized Lac underwent a direct quasi-reversible electrochemical reaction.The value of the electron transfer rate constant ks was estimated to be 0.770 s-1,indicating a reasonably fast electron transfer between the immobilized Lac and the underlying electrode.The surface concentration (I-) of Lac was estimated to be 2.730 × 10-12 mol/cm2.Further experimental results showed that the immobilized Lac displayed an appreciable electrocatalytic activity to the electrochemical reduction of O2.These properties could be attributed to the particular structure of loosely packed nanometer-scale carbon whiskers and the existence of a large amount of oxygen-containing groups.The immo- bilization method and the novel carrier (MCWC) may find new applications in fabricating the biocatalysts for biofuel cells.
基金supported by the National Key R&D Program of China(2019YFC1804102)the National Natural Science Foundation of China(32171615,41877372).
文摘Carbon fibers(CFs)demonstrate a range of excellent properties including(but not limited to)microscale diameter,high hardness,high strength,light weight,high chemical resistance,and high temperature resistance.Therefore,it is necessary to summarize the application market of CFs.CFs with good physical and chemical properties stand out among many materials.It is believed that highly fibrotic CFs will play a crucial role.This review first introduces the precursors of CFs,such as polyacrylonitrile,bitumen,and lignin.Then this review introduces CFs used in BESs,such as electrode materials and modification strategies of MFC,MEC,MDC,and other cells in a large space.Then,CFs in biosensors including enzyme sensor,DNA sensor,immune sensor and implantable sensor are summarized.Finally,we discuss briefly the challenges and research directions of CFs application in BESs,biosensors and more fields.
基金This work was supported by the National Basic Research Program of China(No.2010CB934700)the National Natural Science Foundation of China(Nos.20973019,50902007,and 50725208).
文摘Monodisperse TiO2 nanoparticles and urchin-like hierarchical TiO2 nanospheres assembled with ultrathin quantum nanowires(about 2 nm)have been synthesized by a simple template-free wet chemical method.The morphology,structure,and crystallinity of the TiO2 nanomaterials were investigated by field emission scanning electron microscopy(FESEM),X-ray diffraction(XRD),and high resolution transmission electron microscopy(HRTEM).Electrochemical measurements with the hierarchically nanostructured TiO2 nanospheres as an electrode showed much better reversibility for direct electrochemistry of cytochrome c(cyt c)and much higher sensitivity than for an electrode composed of the monodisperse TiO2 nanoparticles.The excellent performance of the hierarchical TiO2 nanospheres may result from a quantum size effect,and their favorable nanostructure(with the presence of an abundance of both uniform macropores and mesopores),excellent structural stability and high specific surface area.The relative ionic strength had significant effect on the direct electrochemistry.Very high ionic strengths relative to cyt c concentration(I/c)induced a conformational change of cyt c on the nanostructure-coated electrode,from the native state to a partially unfolded one in 25 mmol/L phosphate buffer solution(pH 6.8).
基金supported by the Spanish Ministry of Science,Innovation and Universities projects CTM2017-91879-EXP and PID2019-103989RB-100a predoctoral grant from UAB(PIF 2017e2018).
文摘Using bioelectrochemical systems(BESs)to provide electrochemically generated hydrogen is a promising technology to provide electron donors for reductive dechlorination by organohalide-respiring bacteria.In this study,we inoculated two syntrophic dechlorinating cultures containing Dehalobacter and Dehalobacterium to sequentially transform chloroform(CF)to acetate in a BES using a graphite fiber brush as the electrode.In this co-culture,Dehalobacter transformed CF to stoichiometric amounts of dichloromethane(DCM)via organohalide respiration,whereas the Dehalobacterium-containing culture converted DCM to acetate via fermentation.BES were initially inoculated with Dehalobacter,and sequential cathodic potentials of-0.6,-0.7,and -0.8 V were poised after consuming three CF doses(500 μM)per each potential during a time-span of 83 days.At the end of this period,the accumulated DCM was degraded in the following seven days after the inoculation of Dehalobacterium.At this point,four consecutive amendments of CF at increasing concentrations of 200,400,600,and 800 μM were sequentially transformed by the combined degradation activity of Dehalobacter and Dehalobacterium.The Dehalobacter 16S rRNA gene copies increased four orders of magnitude during the whole period.The coulombic efficiencies associated with the degradation of CF reached values>60% at a cathodic potential of -0.8 V when the degradation rate of CF achieved the highest values.This study shows the advantages of combining syntrophic bacteria to fully detoxify chlorinated compounds in BESs and further expands the use of this technology for treating water bodies impacted with pollutants.
基金Project supported by the National Natural Science Foundation of China
文摘The investigation of interactions of DNA with other molecules, whose results may be helpful to understanding some diseases and the mechanisms, by which some medicines (especially antitumor drugs) act, is of great importance in elucidating the structures of DNA and their function. Many studies of interactions of DNA with porphyrins have
基金Project supported by the National Natural Science Foundation of China.
文摘The electrochemical reduction behavior of bilirubin (BR) at platinum electrode in DMF was investigated by cyclic voltammetry, in situ electron spin resonance spectroscopy and in situ rapid scanning thin layer spectroelectrochemistry. Experimental results revealed that the reduction of BR firstly undergoes an ECE process: GRAPHICS The generated (BR)(2)(3-). can be re-oxidized to BR and then to purpurin (Pu) by a series of oxidation processes: GRAPHICS However, the re-reduction reactions of Pu are not the reverse processes. The different reduction mechanisms are discussed in detail.
基金Project supported by the National Natural Science Foundation of China.
文摘Several aspects of the application of silver electrode to the electrochemical studies of hemoglobin have been discussed in this paper. The silver electrode could not only be used directly as the electrode for the electrochemical studies of hemoglobin, but also react with phenothiazine and benzimidazole to give stable and useful mediator-coated electrodes. In addition, the silver electrode could help sodium dodecyl sulfate to give full play to its promoting effect on the protein.
