Different Concentrations Of Mercury Research Articles

Real-time monitoring of mercury(II) in water and food samples using a quinoline-based ionic probe

Herein, a novel ionic fluorescent probe for mercury(II) detection is presented consisting of a functional quinoline-based IL. Interestingly, the probe displayed high sensitivity (0.8 nM) and selectivity through the regulation function of electrostatic attraction, where its performance was significantly superior to that of quinoline probes without negative charge. Furthermore, the probe was found to exhibit two different fluorescent signals and colorimetric signals in the presence of different concentrations of mercury(II), which was consistent with the reaction mechanisms of the generation of large conjugated systems and the formation of anion-mercury(II) complexes. Moreover, this probe could be further loaded on a simple filter paper to serve as a visual paper sensor due to its adequate response time of less than 5 s. This regulation function strategy of electrostatic attraction has excellent potential for use in the precise detection of targeted analytes in real complex samples with improved accuracy and selectivity.

The trafficking of HgII by alleviating its toxicity via Citrobacter sp. IITISM25 in batch and pilot-scale investigation

The study aims to see how effective the Citrobacter species strain is in removing HgII under stressful conditions. For this, a response surface methodology was chosen to optimized pH, temperature, and biomass for effective biotransformation of HgII. The optimized value for pH, temperature, and biomass were 6.5, 30 °C, and 2 mg/l with 89% HgII removal potential. TEM-EDX showed accumulated mercury onto the bacterial surface. Pot study was conducted to check the potentiality of this strain in alleviating the toxicity in Solanum lycopersicum L. under different concentrations of mercury. The enhancement in antioxidative enzymes, as well as mercury accumulation, was observed in test plants inoculated with IITISM25. Obtained result showed a greater accumulation of mercury in the root system than that of the shoot system due to poor translocation. Moreover, mercury reductase enzyme synthesis was also boosted by the addition of β-mercaptoethanol and L-cysteine. The optimized condition for maximum enzyme synthesis was at pH 7.5 and temperature 30 °C with Km = 48.07 μmol and Vmax = 9.75 μmol/min. Thus, we can say that Citrobacter species strain IITISM25 can be effectively applied in remediation of HgII stress condition as well as promotion of Solanum lycopersicum L growth under stress conditions as a promising host.

Mercury-instructed assembly (MiA): architecting clathrin triskelion-inspired highly functional C3-symmetric triskelion nanotorus functional structures into microtorus structures.

To detect heavy metal toxicity using self-assembled nanostructures, a clathrin triskelion-inspired highly functional C3-symmetric trimerized biotinylated di-tryptophan peptide was used. This triskelion peptide is known to self-assemble into nanotorus-like structures and can therefore act as a nanocage for various analytes. In this work, in addition to spectroscopy, force and electron microscopy were successfully used to detect the effect of toxic metal ions such as zinc, cadmium, and mercury by exploiting the change in the nanotorus morphology. Different concentrations of mercury led to the expansion of nanotorus structures into microtori. Therefore, we provide a unique application of heavy metal toxicity by utilizing "material nanoarchitectonics" to architect nanotorus structures into higher-order microtorus structures, as instructed by mercury. Such a strategy can make heavy metal sensing easier for materials scientists and open new avenues for biomedical/environmental science applications.

Mapping the distribution of mercury (II) chloride in zebrafish organs by benchtop micro-energy dispersive X-ray fluorescence: A proof of concept

BackgroundMercury (Hg) is a globally ubiquitous pollutant and one of the most dangerous metal contaminants, which presents a high risk of bioaccumulation in living organisms. In this study, we mapped the distribution of Hg and other trace elements in zebrafish (Danio rerio), which were exposed to mercury (II) chloride in order to assess its toxicity, bioaccumulation and distribution in fish organs. MethodsAdult zebrafish were exposed for 7 days to different concentrations of mercury (II) chloride and the elemental distribution was obtained through the micro-energy dispersive X-ray fluorescence technique (μ-EDXRF). ResultsThe results showed that Hg levels, measured in fish tissues, were indicative of bioaccumulation within some of its organs (e.g. visceral mass, gills), and that the physiological processes of accumulation were highly dose-dependent. In addition, the results showed higher concentrations of Hg in the gills. Moreover, other trace elements (e.g. Fe, Cu and Zn) levels were not altered after fish exposure to mercury(II) chloride. ConclusionThe μ-EDXRF results were assessed along with the determination of some oxidative stress biomarkers (e.g. antioxidant enzymes) to understand the effects behind the Hg bioaccumulation and toxicity. These results suggest that the metabolic changes in zebrafish due to the exposure to Hg are consistent with oxidative stress.

Colorimetric Determination of Mercury(II) by Secondary Gold Nanoparticles Formation on Primary Gold Nanoparticles as an Efficient Nanozyme

Gold nanoparticles (Au-NPs) shows promise enzyme-like activity for hydrogen peroxide decomposition and produced free electrons for metal ion reduction. Thus, we focused on the design and construction of primary Au-NPs (p-Au-NPs) for decomposition hydrogen peroxide and subsequently reduction of Au3+ to form secondary Au-NPs (s-Au-NPs). Since mercury(II) as soft metal ion can make amalgam with the Au-NPs this can be applied as a boosting idea for indirect detection of mercury(II). Therefore, s-Au-NPs preparation in presence of different concentrations of mercury(II) on surface of p-Au-NPs that cause a color change by final oxidation of 3,4-diaminotoluene while s-Au-NPs/p-Au-NPs cannot oxidize 3,4-diaminotoluene marker and no color change is achieved become as a goal. This occurrence causes a colorimetric procedure, from mauve to dark wine, which facilitates determination of mercury(II) ions in a reasonable range from 2.15 to 25.12 µM with a UV–Vis spectrometer. Sensor characterized by analysis such as UV–Vis, DLS, SEM, EDS, XRD and FT-IR. At last, accuracy of the model investigated with recovery process and observed that method could be advantageously applied as a simple method for the determination of mercury (II) in real samples have been developed to monitor the water quality by tracing different amount of analyte ions in samples. The different water sample such as lake water, tap water, and any water with the necessity of checking the quality of it to help the environment for places with the lack of high-tech technology.

Orthogonal paper biosensor for mercury(II) combining bioluminescence and colorimetric smartphone detection

Mercury contamination in the environment has reached alarming levels. Due to its persistence and bioaccumulation, mercury is one of the most widespread toxic heavy metals found in air, water and food. Thus, it is mandatory to monitor mercury and its compounds, and the availability of sensitive and rapid biosensors is highly valuable.We developed a low-cost biosensor for orthogonal detection of mercury(II) integrating three different biorecognition principles on a three-leaf paper: i) a mercury-specific bioluminescent Escherichia coli bioreporter strain expressing NanoLuc luciferase as reporter protein, ii) a purified β-galactosidase (β-gal) enzyme which is irreversibly inhibited by mercury and other metal ions, and iii) an Aliivibrio fischeri bioluminescent strain which is used to quantitatively assess sample toxicity and correct the analytical signal accordingly.Both sensory elements and substrates, Furimazine for the bioluminescent reporter strain and chlorophenol red-β-D-galactopyranoside for colorimetric detection of β-gal, were integrated in the paper sensor to provide a stable all-in-one disposable cartridge which can be easily snapped into a smartphone with a clover-shaped 3D printed housing. This is the first integration of bioluminescence and colorimetric detection on a smartphone-paper sensor, providing a readout within 15 and 60 min for the colorimetric and bioluminescent detection respectively. The biosensor was applied to water samples spiked with different concentrations of mercury, interferents and toxic chemicals providing a limit of detection for Hg(II) at the ppb levels.

Modelling the Effect of Heavy Metal on the Growth Rate of an SDS-degrading Pseudomonas sp. strain DRY15 from Antarctic soil

The SDS-degrading bacterium Pseudomonas sp. strain DRY15 was strongly inhibited by heavy metals especially mercury. Growth of the SDS-degrading bacterium at various concentrations of mercury shows a sigmoidal pattern with lag periods ranging from 7 to 10 h. As the concentration of mercury was increased, the overall growth was inhibited with 1.0 g/L causing an almost cessation of bacterial growth. The modified Gompertz model was utilized to obtain growth rates at different concentrations of mercury. The growth rates obtained from the modified Gompertz model was then modelled according to the modified Han-Levenspiel, Wang, Liu, modified Andrews, the Amor and Shukor models. Out of the five models, only the Shukor, Wang, modified Han-Levenspiel and the Liu models were able to fit the curve, whilst the modified Andrews and Amor models were unable to fit the curves. The best model was Shukor based on the lowest values for RMSE and AICc, highest adjusted correlation coefficient (adR2) and values of AF and BF closest to unity. The parameters obtained from the Shukor model, which are Sm, max and n which represent critical heavy metal ion concentration (mg/L), maximum growth rate (h-1) and empirical constant values were 6.0 (95%, confidence interval from 5.87 to 6.14), 0.09 (95%, confidence interval of 0.086 to 0.096) and 4.2 (95%, confidence interval from 3.1 to 5.2), respectively.

Green synthesized carbon quantum dots from Prosopis juliflora leaves as a dual off-on fluorescence probe for sensing mercury (II) and chemet drug

In this article, a facile and green dual fluorescence sensor was developed for mercury and chemet as an anti-poisoning drug for heavy metal ions. The method is based on “off-on” fluorescence of carbon quantum dots (CQDs) prepared from Prosopis juliflora leaves as a green and low cost source. The synthesis of CQDs was easily performed with a rapid one pot process and the prepared CQDs exhibited a blue luminescence with a 5% quantum yield. The off fluorescent is observed in the presence of different concentrations of mercury (II) that is specifically recovered with the addition of chemet. The gradually recovered fluorescence is due to the high affinity of chelating property of succimer drug towards mercury (II) with a good restoration. Under the optimized condition, two linear calibrations were validated in the range of 5–500 ng mL−1 and 2.5–22.5 ng mL−1 for Hg (II) and chemet, respectively. The limit of detection (LOD) based on 3Sb was 1.26 ng mL−1 (or 6.3 nM) for Hg (II) and 1.4 ng mL−1 for chemet. The relative standard deviation of the fluorescent probe for 50 ng mL−1 of Hg (II) and 10 ng mL−1 of chemet was 4.5% and 1.3% (n = 10), respectively. This methodology was applied to successful measurements of Hg (II) and chemet in the water and human serum samples, respectively.

In situ stabilization of some mercury-containing soils using organically modified montmorillonite loading by thiol-based material

In situ stabilization is a remediation technology that reduces the availability of mercury in contaminated soils by adding chemical substances. In this study, thiol-functionalized montmorillonite modified by organic surfactant (Mont-OR-SH) was used to stabilize soils contaminated with different concentrations of mercury. The Mont-OR-SH used in this study was obtained by grafting the thiol group (–SH) to the montmorillonite modified by organic surfactant (Mont-OR). The physicochemical characteristics were analyzed by XRD, FTIR, and SEM, confirming that the Mont was successfully functionalized, while the concentration of mercury was analyzed by the cold-vapor atomic absorption (CVAA) method. Contaminated soils were mixed with Mont-OR and Mont-OR-SH at different dosages. The effect of stabilization time was investigated when the Mont-OR-SH dosages were 7 wt% and 8 wt%, and five different stabilization pH values were used to investigate the influence on stabilization when the stabilizer dosages was 8 wt%. A sequential extraction procedure and a toxicity leaching procedure were used to evaluate remediation performance. The result indicated that the Mont-OR-SH was effective in stabilizing mercury-contaminated soil, and the stabilization capacity was greatly enhanced upon thiol grafting. Stabilization efficiency for both kinds of soil was greater than 90% after stabilizing by Mont-OR-SH. For two kinds of soils, with a stabilization duration of 14 days, the stabilizer dosage was about 8 wt% and the pH of the leaching was 8.0; the stabilization efficiency could reach 91.7% and 96.7% when stabilized by Mont-OR-SH which is higher than 60.4% and 82.4% when stabilized by Mont-OR. For two kinds of soils, the contents of neutral fraction were reduced and changed to acid fraction, base fraction, sulfide fraction, and residual fraction. Stabilization capacity of Mont-OR was greatly enhanced after the thiol group was loaded; the stabilization process using Mont-OR-SH was effective to treat mercury-containing soils.

Early Diagnosis of Mercury Stress of Wheat Seedlings Using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy

ABSTRACTThe aim of the study was the non-destructive and rapid evaluation of the phytotoxicity of different concentrations of mercury (0.2, 0.4, 0.6, 0.8, and 1 mM) on the biochemical profile of wheat seedlings using attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy in combination with principal component analysis. Infrared spectra of the leaves of control and mercury-treated wheat seedlings were recorded in the spectral region from 4000 to 485 cm−1. The preprocessing of the recorded spectra by second derivation enhanced the specificity of the infrared bands. The area of the bands estimated by curve fitting was used for the relative quantitative estimation of the biochemical changes involved. The principal component analysis of the acquired spectral measurements discriminated between the biochemicals of the control and mercury-treated wheat seedlings. The result showed that mercury (0.2–1 mM) significantly enhanced the content of the cell wall polysaccharides, amino acids, β-sheet component of proteins, and lipids in the leaves accompanied by reduction in the amount of α-helix. The change in β-sheet/α-helix ratio indicated mercury induced structural changes in the secondary structure of proteins. The increase in the levels of methylene bands and carboxyl bands indicates changes in lipid configuration and peroxidative damage caused by mercury. The results of this study demonstrate the potential of ATR–FTIR in combination with principal component analysis as an environmental monitoring tool for the identification of plant populations affected by environmental factors like heavy metal stress prior to the appearance of visual signs of toxicity.

Presencia de bacterias rizosféricas resistentes a mercurio en suelos del sur de Bolívar, Colombia

El objetivo del presente estudio fue aislar bacterias rizosféricas de muestras provenientes de la Mina de Santa Cruz, departamento de Bolívar, con el propósito de evaluar in vitro la actividad de resistencia a diferentes concentraciones de mercurio. Las muestras fueron recolectadas aleatoriamente de diferentes sitios de cerca de la mina de oro Santa Cruz, a partir de la cuales de aislaron bacterias rizosférico. Se evaluó in vitro la capacidad de resistencias de las bacterias a diferentes concentraciones de mercurio en forma de cloruro de mercurio (HgCl2) a concentraciones de 50 ppm, 100 ppm, 150 ppm, 200 ppm y 250 ppm; así mismo las bacterias resistentes a este metal se utilizaron para evaluar la capacidad de promoción de crecimiento en las plantas. Los resultados mostraron que la bacteria identificada como Pseudomonas luteola, resistió in vitro a 200 ppm de cloruro de mercurio (HgCl2), y cualitativamente tuvo la capacidad de producir sideróforos y fijar biológicamente nitrógeno. P luteola fue aislada de la rizósfera cerca de la mina de Santa Cruz en el departamento de Bolívar, Colombia, con suelos con altas concentraciones de mercurio y con reacción del suelo extremadamente acida.

Extracellular polymeric substances with metal adsorption capacity produced by Pseudoalteromonas sp. MER144 from Antarctic seawater.

The EPS-producing Pseudoalteromonas sp. MER144 was selected among 606 isolates from Antarctic seawater due to its evident slimy appearance on agar plates. The production of EPSs was enhanced by a step-by-step approach varying the carbon source, substrate and NaCl concentrations, temperature, and pH. Optimal conditions for the EPS production resulted at temperature of 4°C and pH7, with addition of 2% sucrose (w/v) and 3% NaCl (w/v). EPSs produced under optimal conditions were chemically characterized, resulting in a moderate carbohydrate content (35%), uronic acids (14%), and proteins (12%). Monosaccharide composition was estimated to be Glu:Man:GluN:Ara:GluA:GalA:Gal (1:0.36:0.26:0.06:0.06:0.05:0.03), while the estimated molecular weight was about 250kDa. The addition of sucrose in the culture medium, by stimulating the EPS production, allowed MER144 to tolerate higher concentrations of mercury and cadmium. This finding was probably dependent on the presence of uronic acids and sulfate groups, which can bind cations, in the extracted EPSs. Monitoring EPS production under optimal conditions at different concentrations of mercury and cadmium revealed that EPS amounts increased at increasing heavy metal concentrations, indicating an adaptation to the stress conditions tested.

Effects of different concentrations of mercury on accumulation of mercury by five plant species

The paper studied the absorption of Hg by five common herb species selected, Opuntia stricta, Aloe vera, Setcreasea purpurea, Chlorophytum comosum and Oxalis corniculata, in solution with different levels of mercury. We compared the accumulation of roots and shoots of the plants selected in medium containing different concentrations of mercury. The study was to explore what extent of mercury the five plant species were suitable for absorbing and transferring. The mercury amount uptake by five herb species was tested by CVAAS. The results demonstrated that the effect of different concentrations of mercury on the accumulation condition of roots was greater than that of shoots. There was an ideal Hg concentration for transfer by each plant species. Oxalis corniculata was the most suitable for transferring Hg and was more suitable for repairing soils with Hg at concentrations of less than 500μg/L.

Molecular characterization and expression of the p38 MAPK gene from the ridgetail white prawn, Palaemon carinicauda Holthuis, 1950 (Decapoda, Palaemonidae)

The p38 mitogen-activated protein kinases (MAPK) are a kind of Ser/Thr protein kinases that convert extracellular stimuli into a wide range of cellular response, appearing to function not only in stress stimuli but also in development. To explore the function of p38 MAPK in Palaemon carinicauda Holthuis, 1950, we cloned and characterized the full-length cDNA sequence (GenBank accession number KX893515) (designated as Pc-p38). The results showed that the open reading frame (ORF) of Pc-p38 was 1098 bp and it encoded a protein of 365 amino acids. Pc-p38 contained the conserved structures of a Thr-Gly-Tyr (TGY) motif and a substrate-binding site, Ala-Thr-Arg-Trp (ATRW), and was shown to have a close phylogenetic relationship to other p38 MAPKs in crustaceans. The tissue distribution patterns showed that Pc-p38 was widely expressed in all tissues, with highest expression in the hepatopancreas and ovary. Quantitative real-time PCR revealed that Pc-p38 was upregulated during ecdysis, reaching a peak at 5 min post-moult, suggesting that Pc-p38 may be involved in muscle remodeling after moulting. In addition, the expression of Pc-p38 increased following exposure to different concentrations of mercury, in a dose- and time-dependent manner. In conclusion, an Pc-p38 gene was cloned and its role determined at different times post-moult and after stress from different concentrations of mercury, to further reveal the possible functions of p38 MAPK in P. carinicauda.

Mercury enrichment in Brassica napus in response to elevated atmospheric mercury concentrations

Mercury enrichment in response to elevated atmospheric mercury concentrations in the organs of rape (Brassica napus) was investigated using an open top chamber fumigation experiment and a soil mercury enriched cultivation experiment. Results indicate that the mercury concentration in leaves and stems showed a significant variation under different concentrations of mercury in atmospheric and soil experiments while the concentration of mercury in roots, seeds and seed coats showed no significant variation under different atmospheric mercury concentrations. Using the function relation established by the experiment, results for atmospheric mercury sources in rape field biomass showed that atmospheric sources accounted for at least 81.81%of mercury in rape leaves and 32.29% of mercury in the stems. Therefore, mercury in the aboveground biomass predominantly derives from the absorption of atmospheric mercury.

Preparation and Study of the Fluorescence Quenching for Different Core/Shell Structures Quantum Dots with Mercury (II) Induction

The probes and sensors of the semiconductor quantum dots are the topic of intense research because they are able to show high-sensitivity fluorescence quenching under different ions conditions. Herein, different multishell structures of CdSe, CdSe-CdS, and CdSe-CdS-ZnS water-soluble quantum dots have been synthesized in aqueous solution. Transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray powder diffraction indicate that these quantum dots have high stability, homogeneous particle size and good monodispersity. More precisely, with different concentrations of mercury (II) induction, the mechanism of the fluorescence quenching for various structures of the quantum dots is discussed based electron transfer and nonradiative recombination patterns. Obtained results indicate that the core-shell structure of the CdSe-CdS quantum dots has the most beautiful performance, which shows high sensitivity in the detection of mercury (II). Moreover, this work provides some guidelines for the rational design of others fluorescence bioprobes and biosensors.

Use of Swimming Capacity to Evaluate the Effect of Mercury on Poecilia vivipara (Poecilídeos) According to Salinity and Temperature

Use of Swimming Capacity to Evaluate the Effect of Mercury on Poecilia vivipara (Poecilideos)According to Salinity and Temperature This study aimed to investigate the effects of the exposed to mercury, under the influence of different temperatures and salinities, on the swimming capacity of Poecilia vivipara. For this purpose, swimming capacity was estimated through exposure in aqueous medium, in twelve possible combinations, with different concentrations of mercury (0.0 μg/L, 10 μg/L, 20 μg/L and 30 μg/L), three salinities (35, 20 and 5) and three temperatures (25oC, 20oC and 15oC). The results show that the swimming capacity decreased according to the mercury concentration in all temperatures and salinities studied. At the highest tested concentration of mercury at 25°C, there was a decrease on swimming capacity of 84.4%, 91.2% and 97.1% in the salinities 35, 20 and 5, respectively. Generally speaking, averages were significantly different compared to control at the highest concentration of the mercury and in all temperatures. At lower salinity employed there was a corresponding increase in mercury toxicity and a decrease in swimming capacity. Swimming activity is a valid parameter and consistent index of the sublethal toxic effect that can be easily incorporated into the assay protocols to work with standard toxicity tests.

Membrane potential differences and viability of grapevine root cells treated with HgCl<sub>2</sub>

The effect of mercury (Hg) on the electrophysiological and permeability properties of grapevine adventitious root cells was examined. In short-term experiments, the apical segments of adventitious roots were treated with different concentrations of mercury (0.01 µmol/L to 2 µmol/L HgCl<sub>2</sub>), and trans-membrane electrical potential differences (E<sub>M</sub>) were monitored in root cortical cells, localized in distinct root zones. Based on Hg-induced decrease of E<sub>M</sub>, we can confirm that the depolarization of the membrane is an instant Hg-response and the extent of E<sub>M</sub> decrease is not only time- and concentration dependent, but also related to the developmental stage of cells and their localization on root axis. The sensitivity of root cells to Hg declined in the direction of cell division zone > cell elongation zone > absorption zone. Long-term treatment of roots with 2 µmol/L mercury showed that Hg-induced decrease of E<sub>M</sub> was accompanied by an increase of K<sup>+</sup> efflux and a decrease of the diffusion potential (E<sub>D</sub>) values. Application of fusicoccin (H<sup>+</sup>-ATPase activator) to the root medium caused an immediate hyperpolarization of the membrane in control and Hg-treated cells. Laser scanning confocal microscopy analysis confirmed that Hg reduced cell viability, which was accompanied with the occurrence of cell death hallmarks, like condensation of protoplasts, nuclei fragmentation and deposition of granular material.

Bioaccumulation of mercury in the trophic chain of flatfish from the Baltic Sea

Mercury concentrations in three flatfish species – flounder (Platichtys flesus), plaice (Pleuronectes platessa), and Baltic turbot (Scophthalmus maximus), netted in the southern Baltic Sea were assessed and compared to concentrations of this metal in sediments, sea water, and flatfish food – bivalve Macoma balthica, isopod Saduria entomon, and sprat (Sprattus sprattus). Collected simultaneously with flatfish in 2009 and 2010. Different concentrations of mercury depending on species, tissue or organ, sex, individual length, kind of food, and region were determined. The muscle tissues of turbot had the highest concentrations of the metal. The bioaccumulation (BF) and biomagnification (BMF) factors has been counted showing that the muscle tissues of turbot have maximum affinity for mercury, and thus best reflected the metal contamination of the Baltic Sea environment. The data suggest that the common Baltic turbot (S. maximus) is an important model species, suitable and cost-effective to biomonitor environmental mercury pollution for ecological research.

Determination of mercury and nickel by amperometric biosensor prepared with thermostable lactate dehydrogenase

Response of biosensor prepared with the thermostable bacterial LDH enzyme was analyzed in the presence of mercury and nickel. For electrode preparation, the enzyme was purified and immobilized on a gold sheet coated by PGA-pyrrole polymeric material. The working electrode was tested at increasing concentration of lactate in the presence of two different concentrations of mercury and nickel. Current response of biosensor decreased from 0.32 μA to 0.09 μA and 4.13 μA to 2.63 μA when 25×10 −7 mmol/L mercury and 17×10 −5 mmol/L nickel were included in the working solution, respectively. Sensitivity of the electrode decreased from 0.010 2 μA/(mmol·L −1) to 0.0043 μA/(mmol·L −1) in the presence of 25×10 −7 mmol/L mercury. On the other hand, the presence of nickel did not result in a decrease in electrode sensitivity. The results pointed out that the prepared biosensor is useful to detect mercury in a sample containing both mercury and nickel together.