Influence of Hg(II) and Pb(II) ions on C-Phycocyanin (C-PC) from cyanobacteria Spirulina platensis was investigated using Fluorescence spectroscopy. Fluorescence measurements demonstrate quenching of C-PC emission by ...Influence of Hg(II) and Pb(II) ions on C-Phycocyanin (C-PC) from cyanobacteria Spirulina platensis was investigated using Fluorescence spectroscopy. Fluorescence measurements demonstrate quenching of C-PC emission by Hg(II) and Pb(II), and blue shifts in the fluorescence spectra. The effect of DNA on the fluorescence of Hg(II)-and Pb(II)-C-PC (from Spirulina platensis) complexes was also studied. It was shown that the fluorescence intensity of Hg-C-PC after addition of DNA gave rise to the fluorescence buildup. At the same time, addition of DNA to the Pb(II)-C-PC complexes showed no such effect. In the case of Hg(II)-C-PC, fluorescence intensity significantly decreases in time, while for Pb(II)-C-PC, decrease of the fluorescence intensity is not significant, but blue shift of the peak takes place.展开更多
Cornulaca monacantha (CM) a desert plant has been utilized as adsorbent material for the removal of Hg (II) ions from contaminated water after treatment with acrylamide in alkaline medium to form carbamoylethylated Co...Cornulaca monacantha (CM) a desert plant has been utilized as adsorbent material for the removal of Hg (II) ions from contaminated water after treatment with acrylamide in alkaline medium to form carbamoylethylated Cornulaca monacantha (CECM). Three levels of CECM having different nitrogen content were prepared. The CECM samples were characterized by estimating the nitrogen content. The ability of CECM to adsorb Hg (II) was investigated by using batch adsorption procedure. The data of the adsorption isotherm was tested by the Langmuir, Freundlich and Temkin models. The removal of Hg (II) onto CECM particles could be well described by the pseudo-second order model. The adsorption rate of mercury was affected by the initial Hg (II) ion concentration, initial pH, adsorbent concentration and agitation time as well as extent of modification. The adsorption experiments indicated that the CECM particles have great potential for the removal of Hg (II) from contaminated water. The maximum adsorption capacity, Qmax of the CECM towards Hg (II) ions was found to be 384.6 mg/g at 30?C. Similarly, the Freundlich constant, n was found to be 2.03 at 30°C.展开更多
The present work deals with the equilibrium adsorption of Hg(II) onto carbonized Rosmarinus officinalis leaves (ACROL) as a new adsorbent from aqueous solution and it has been investigated. ACROL samples were prepared...The present work deals with the equilibrium adsorption of Hg(II) onto carbonized Rosmarinus officinalis leaves (ACROL) as a new adsorbent from aqueous solution and it has been investigated. ACROL samples were prepared by physical carbonization at 773 K for 1 h. Titration method was used to determine the concentration of Hg(II) before and after adsorption onto ACROL by ethylenediaminetetraacetic acid, EDTA, as chelating agent. Batch equilibrium studies were carried out under different experimental conditions such as Hg(II) concentration and temperature. The relationship between the amount of Hg(II) onto ACROL can be described using four tow-parameter isotherm models. The equilibrium sorption data were analyzed using Freundlich, Langmuir, Dubinin-Radushkevich (DRK) and Temkin isotherms. The experimental results were found to fit the Langmuir isotherm model with a monolayer adsorption capacity of 588.2 mg/g at 318 K, while they were found to fit the Freundlich isotherm model at 298 K. The KL was decreased with increasing temperature, indicating a bond strength between Hg(II) and ACROL decreased with increasing temperature and sorption is exothermic. From DRK isotherm, free energy, E, was higher than 31 kJ/mol suggesting the Hg(II) adsorption onto ACROL chemical sorption. The thermodynamic studies revealed that the process is spontaneous nature of Hg(II) adsorption by ACROL and exothermic. The findings from this research show that ACROL has capability to remove Hg(II) from aqueous solutions.展开更多
This work demonstrates a smartphone-based automated fluorescence analysis system(SAFAS)for point-of-care testing(POCT)of Hg(Ⅱ).This system consists of three modules.The smartphone module is used to provide an excitat...This work demonstrates a smartphone-based automated fluorescence analysis system(SAFAS)for point-of-care testing(POCT)of Hg(Ⅱ).This system consists of three modules.The smartphone module is used to provide an excitation light source,and to collect and analyze fluorescent images.The dark box module is applied to integrate the desired optical elements and offers a dark environment.The cost of the integrated dark box mainly includes the upper cover,box body,lower bottom,¯xture and some optical elements which is about$109.The chip module is used for fluorescence sensing,which is composed of an upper plate,bottom plate and cloth-based chip.Due to the integration of multiple smartphone functions,the SAFAS eliminates the need for additional power sources,light sources and analysis systems.The dark box and upper and bottom plates are made by 3D printer.The cloth-based chip(about$0.005 for each chip)is fabricated using the wax screenprinting technique,with no need for expensive and complex fabrication equipments.To our knowledge,the cloth-based microfluidic fluorescence detection method combined with smartphone functions is first reported.By using optimal conditions,the designed system can realize the quantitative detection of Hg(Ⅱ),which has a linear range of 0.001–100μgmL^(-1)and a detection limit of 0.5 ngmL^(-1).Additionally,the SAFAS has been successfully applied for detecting Hg(Ⅱ)in actual water samples,with recoveries of 100.1%–111%,RSDs of 3.88%–9.74%,and fast detection time of about 1 min.Obviously,the proposed SAFAS has the advantages of high sensitivity,wide dynamic range,acceptable reproducibility,good stability and low cost.Therefore,it is believed that the presented SAFAS has great potential to perform the POCT of Hg(II)in different water samples.展开更多
文摘Influence of Hg(II) and Pb(II) ions on C-Phycocyanin (C-PC) from cyanobacteria Spirulina platensis was investigated using Fluorescence spectroscopy. Fluorescence measurements demonstrate quenching of C-PC emission by Hg(II) and Pb(II), and blue shifts in the fluorescence spectra. The effect of DNA on the fluorescence of Hg(II)-and Pb(II)-C-PC (from Spirulina platensis) complexes was also studied. It was shown that the fluorescence intensity of Hg-C-PC after addition of DNA gave rise to the fluorescence buildup. At the same time, addition of DNA to the Pb(II)-C-PC complexes showed no such effect. In the case of Hg(II)-C-PC, fluorescence intensity significantly decreases in time, while for Pb(II)-C-PC, decrease of the fluorescence intensity is not significant, but blue shift of the peak takes place.
文摘Cornulaca monacantha (CM) a desert plant has been utilized as adsorbent material for the removal of Hg (II) ions from contaminated water after treatment with acrylamide in alkaline medium to form carbamoylethylated Cornulaca monacantha (CECM). Three levels of CECM having different nitrogen content were prepared. The CECM samples were characterized by estimating the nitrogen content. The ability of CECM to adsorb Hg (II) was investigated by using batch adsorption procedure. The data of the adsorption isotherm was tested by the Langmuir, Freundlich and Temkin models. The removal of Hg (II) onto CECM particles could be well described by the pseudo-second order model. The adsorption rate of mercury was affected by the initial Hg (II) ion concentration, initial pH, adsorbent concentration and agitation time as well as extent of modification. The adsorption experiments indicated that the CECM particles have great potential for the removal of Hg (II) from contaminated water. The maximum adsorption capacity, Qmax of the CECM towards Hg (II) ions was found to be 384.6 mg/g at 30?C. Similarly, the Freundlich constant, n was found to be 2.03 at 30°C.
文摘The present work deals with the equilibrium adsorption of Hg(II) onto carbonized Rosmarinus officinalis leaves (ACROL) as a new adsorbent from aqueous solution and it has been investigated. ACROL samples were prepared by physical carbonization at 773 K for 1 h. Titration method was used to determine the concentration of Hg(II) before and after adsorption onto ACROL by ethylenediaminetetraacetic acid, EDTA, as chelating agent. Batch equilibrium studies were carried out under different experimental conditions such as Hg(II) concentration and temperature. The relationship between the amount of Hg(II) onto ACROL can be described using four tow-parameter isotherm models. The equilibrium sorption data were analyzed using Freundlich, Langmuir, Dubinin-Radushkevich (DRK) and Temkin isotherms. The experimental results were found to fit the Langmuir isotherm model with a monolayer adsorption capacity of 588.2 mg/g at 318 K, while they were found to fit the Freundlich isotherm model at 298 K. The KL was decreased with increasing temperature, indicating a bond strength between Hg(II) and ACROL decreased with increasing temperature and sorption is exothermic. From DRK isotherm, free energy, E, was higher than 31 kJ/mol suggesting the Hg(II) adsorption onto ACROL chemical sorption. The thermodynamic studies revealed that the process is spontaneous nature of Hg(II) adsorption by ACROL and exothermic. The findings from this research show that ACROL has capability to remove Hg(II) from aqueous solutions.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(2019A1515011284)Guangzhou Basic and Applied Basic Research Foundation(202002030265).
文摘This work demonstrates a smartphone-based automated fluorescence analysis system(SAFAS)for point-of-care testing(POCT)of Hg(Ⅱ).This system consists of three modules.The smartphone module is used to provide an excitation light source,and to collect and analyze fluorescent images.The dark box module is applied to integrate the desired optical elements and offers a dark environment.The cost of the integrated dark box mainly includes the upper cover,box body,lower bottom,¯xture and some optical elements which is about$109.The chip module is used for fluorescence sensing,which is composed of an upper plate,bottom plate and cloth-based chip.Due to the integration of multiple smartphone functions,the SAFAS eliminates the need for additional power sources,light sources and analysis systems.The dark box and upper and bottom plates are made by 3D printer.The cloth-based chip(about$0.005 for each chip)is fabricated using the wax screenprinting technique,with no need for expensive and complex fabrication equipments.To our knowledge,the cloth-based microfluidic fluorescence detection method combined with smartphone functions is first reported.By using optimal conditions,the designed system can realize the quantitative detection of Hg(Ⅱ),which has a linear range of 0.001–100μgmL^(-1)and a detection limit of 0.5 ngmL^(-1).Additionally,the SAFAS has been successfully applied for detecting Hg(Ⅱ)in actual water samples,with recoveries of 100.1%–111%,RSDs of 3.88%–9.74%,and fast detection time of about 1 min.Obviously,the proposed SAFAS has the advantages of high sensitivity,wide dynamic range,acceptable reproducibility,good stability and low cost.Therefore,it is believed that the presented SAFAS has great potential to perform the POCT of Hg(II)in different water samples.
