A new cell immobilization method based on the replacement of KCl by KCl+chitosan as the gelling agent was developed. The experimental results showed that through addition of chitosan into gelling agent, the mechanica...A new cell immobilization method based on the replacement of KCl by KCl+chitosan as the gelling agent was developed. The experimental results showed that through addition of chitosan into gelling agent, the mechanical strength and the thermal stability of the carrageenan gel were greatly improved. The new immobilization method was used to entrap a chlorophenol degrading microorganism. The immobilized microbial cells were applied for chlorophenol biodegradation. The experiments demonstrated that immobilized cells exhibit a higher bioactivity in the degradation of chlorophenol than free cells.展开更多
Microcystins(MCs)are a group of closely related toxic cyclic heptapeptides produced by common cyanobacte-ria,which cause lots of accidents and threatens human health.In this paper,an indirect competitive enzyme-linked...Microcystins(MCs)are a group of closely related toxic cyclic heptapeptides produced by common cyanobacte-ria,which cause lots of accidents and threatens human health.In this paper,an indirect competitive enzyme-linked immu-nosorbent assay(ic-ELISA)was established and used to detect microcystin-LR(MC-LR)in drinking and surface waters.The concentration of coating antigen was 5 mg/mL,the dilution of monoclonal antibody MC10E7 was 1:3000,the dilution of enzyme tracer(goat anti-mouse IgG-peroxidase)was 1:3000,the standard concentration of MC-LR ranged from 0.001 mg/L to 30 mg/L,and o-phenylenediamine was used as substrate.The assay showed high relativity with high performance liquid chromatography(HPLC)with a correlation coefficient of more than 99%.The relative standard deviation was less than 10%,the detection limit was achieved down to 0.01 mg/L and up to 5.1 mg/L.The quantitative detection range was from 0.03 mg/L to 3 mg/L,and the antibody had high specificity for[4-arginine]microcystins.It performed well in spite of the influence of the real samples.展开更多
This research describes a fast detection method on the basis of enzyme-linked immunosorbent assay(ELISA)for Escherichia coli in drainage of wastewater treatment plants.Optimized conditions such as the reaction format(...This research describes a fast detection method on the basis of enzyme-linked immunosorbent assay(ELISA)for Escherichia coli in drainage of wastewater treatment plants.Optimized conditions such as the reaction format(sandwich or direct),the concentrations of diluted horse radish peroxidase(HRP)-E.coli conjugate,and anti-HPR antibody and pretreatment of E.coli were studied.Those results showed that the linear range of detection for E.coli was 10 cfu/mL-6×10^(4) cfu/mL.Compared with conventional methods,it is a convenient and sensitive detection method with low cost.展开更多
Screen printing is a promising technology because of its simplicity, low-cost, high reproducibility, and efficiency in large-scale production. In this work, a cobalt-based phosphate sensor was successfully fabricated ...Screen printing is a promising technology because of its simplicity, low-cost, high reproducibility, and efficiency in large-scale production. In this work, a cobalt-based phosphate sensor was successfully fabricated using the screen printing technology for the determination of phosphate concentration in the aqueous solution. The disposable sensor consists of a fully integrated cobalt （Co） electrode, which is a layer of carbon conductive ink （C） physically doped with Co powder, and Ag/AgCI reference electrode. The SEM images show that the morphology of the Co electrode changes after exposure to the phosphate solution, indicating that the expendable reaction exists during the measurement. At the Co/C ratio of 1：99, the cobalt-based phosphate sensor shows phosphate-selective potential response in the range of 10-4 to 10-1 mol/L, yielding a detection limit of lxl0-5 mol/L and a slope of over 30 mV/decade in acidic solution （pH 4.5） for HzPO4-. The proposed screen-printed sensor also ex- hibited significant reproducibility with a small repeated sensing deviation （i.e., relative standard deviation （R.S.D.） of 0.5%） on a single sensor and a small electrode-to-electrode deviation （i.e., R.S.D. 〈 3.2%）. The recovery study of HzPO4- in real wastewater samples gave values from 95.4% to 101.8%, confirming its application potential in the measurement of phosphate in real samples. Apart from its high selectivity, sensitivity, and stability comparable with a conventional bulk Co-wire electrode, the proposed phosphate sensor still yields many other advantages, such as low price, compactness, ease of use, and the possibility of integration with other analytical devices such as flow injection analysis.展开更多
文摘A new cell immobilization method based on the replacement of KCl by KCl+chitosan as the gelling agent was developed. The experimental results showed that through addition of chitosan into gelling agent, the mechanical strength and the thermal stability of the carrageenan gel were greatly improved. The new immobilization method was used to entrap a chlorophenol degrading microorganism. The immobilized microbial cells were applied for chlorophenol biodegradation. The experiments demonstrated that immobilized cells exhibit a higher bioactivity in the degradation of chlorophenol than free cells.
基金This work was supported by the National High-Tech Research and Development(863)Program of China(2002AA649160).
文摘Microcystins(MCs)are a group of closely related toxic cyclic heptapeptides produced by common cyanobacte-ria,which cause lots of accidents and threatens human health.In this paper,an indirect competitive enzyme-linked immu-nosorbent assay(ic-ELISA)was established and used to detect microcystin-LR(MC-LR)in drinking and surface waters.The concentration of coating antigen was 5 mg/mL,the dilution of monoclonal antibody MC10E7 was 1:3000,the dilution of enzyme tracer(goat anti-mouse IgG-peroxidase)was 1:3000,the standard concentration of MC-LR ranged from 0.001 mg/L to 30 mg/L,and o-phenylenediamine was used as substrate.The assay showed high relativity with high performance liquid chromatography(HPLC)with a correlation coefficient of more than 99%.The relative standard deviation was less than 10%,the detection limit was achieved down to 0.01 mg/L and up to 5.1 mg/L.The quantitative detection range was from 0.03 mg/L to 3 mg/L,and the antibody had high specificity for[4-arginine]microcystins.It performed well in spite of the influence of the real samples.
基金This work was supported by the National High-Tech Research and Development(863)Program of China,985 Project from Tsinghua University,and China Postdoctoral Science Foundation.
文摘This research describes a fast detection method on the basis of enzyme-linked immunosorbent assay(ELISA)for Escherichia coli in drainage of wastewater treatment plants.Optimized conditions such as the reaction format(sandwich or direct),the concentrations of diluted horse radish peroxidase(HRP)-E.coli conjugate,and anti-HPR antibody and pretreatment of E.coli were studied.Those results showed that the linear range of detection for E.coli was 10 cfu/mL-6×10^(4) cfu/mL.Compared with conventional methods,it is a convenient and sensitive detection method with low cost.
基金supported by the Major Scientific Equipment Development Project of China(2012YQ030111)the Beijing Natural Science Foundation(8132032)
文摘Screen printing is a promising technology because of its simplicity, low-cost, high reproducibility, and efficiency in large-scale production. In this work, a cobalt-based phosphate sensor was successfully fabricated using the screen printing technology for the determination of phosphate concentration in the aqueous solution. The disposable sensor consists of a fully integrated cobalt （Co） electrode, which is a layer of carbon conductive ink （C） physically doped with Co powder, and Ag/AgCI reference electrode. The SEM images show that the morphology of the Co electrode changes after exposure to the phosphate solution, indicating that the expendable reaction exists during the measurement. At the Co/C ratio of 1：99, the cobalt-based phosphate sensor shows phosphate-selective potential response in the range of 10-4 to 10-1 mol/L, yielding a detection limit of lxl0-5 mol/L and a slope of over 30 mV/decade in acidic solution （pH 4.5） for HzPO4-. The proposed screen-printed sensor also ex- hibited significant reproducibility with a small repeated sensing deviation （i.e., relative standard deviation （R.S.D.） of 0.5%） on a single sensor and a small electrode-to-electrode deviation （i.e., R.S.D. 〈 3.2%）. The recovery study of HzPO4- in real wastewater samples gave values from 95.4% to 101.8%, confirming its application potential in the measurement of phosphate in real samples. Apart from its high selectivity, sensitivity, and stability comparable with a conventional bulk Co-wire electrode, the proposed phosphate sensor still yields many other advantages, such as low price, compactness, ease of use, and the possibility of integration with other analytical devices such as flow injection analysis.
