Detection Of Mercury Research Articles

Effects of water bath digestion and DEENA pretreatment on mercury content detection in soil

There are many sample preparation methods for heavy metal detection of soil samples, but each has its advantages and disadvantages. Based on the above two pretreatment methods, the detection limit, precision, accuracy and actual soil sample measurement value of mercury detection in soil by atomic fluorescence were compared with atomic fluorescence, and the results showed that the automatic digestion and pretreatment system (DEENA) could digest soil samples to meet the requirements of GB/T 22105.1-2008 standard. Moreover, there was no significant difference between the two digestion methods on the detection results of mercury in soil, and the automatic digestion and preparation system (DEENA) was convenient, operable and highly automated, which was more advantageous for sample digestion.

Periodic mesoporous organosilica based sensor for broad range mercury detection by simultaneous downshifting/upconversion luminescence

Lanthanide-based periodic mesoporous organosilica (LnPMO) hollow spheres with interior lanthanide-doped fluorides for luminescence turn-off sensing of Hg2+ with a low detection limit and wide detection range.

Green synthesis of silver nanoparticles using Coffea canephora fruit skin extract and its application for mercury detection in face cream samples

Mercury is one of the most toxic heavy metals causing harmful effects on the human body; meanwhile, mercury is found in some face cream products to give a whitening effect. The upper limit concentration of mercury in skin-lightening products defined by the Food and Drug Administration (FDA) is under one mg/L as Hg2+. A new green analytical spectrophotometric method for mercury analysis has been developed by employing a biological reagent from fruit skin extract of robusta coffee (Coffea canephora) as a bioreductor for silver ions as well as a stabilizer for the AgNPs product. The detection principle of this method is based on the decrease of the color intensity of silver nanoparticles (AgNPs) after the addition of Hg2+ ions due to the re-oxidization of the AgNPs by Hg2+ ions to colorless Ag+ ions. To achieve the most significant sensitivity, linearity of measurement, and validity, the method was optimized toward the volume of AgNPs and reaction time. In this research, the synthesized AgNPs were also characterized by UV-Vis Spectrometry as well as a particle size analyzer (PSA) to determine the size of nanoparticles. The result showed that the optimum conditions were attained at 4mL AgNPs solution and 3-min reaction resulting in a linear measurement of Hg2+ in the range of 0-15mg/L with LOD and LOQ of 0.039 and 0.130mg/L, respectively. This method is quite selective and has been validated by applying it to real face cream samples with satisfactory results supported by average recoveries of close to 100%.

Hybrid films composed of ethyl(hydroxyethyl)cellulose and silica xerogel functionalized with a fluorogenic chemosensor for the detection of mercury in water

Ethyl(hydroxyethyl)cellulose (EHEC) and a silica–based xerogel (SBX) were functionalized with a (18–crown–6)–styrylpyridine precursor (1) to obtain the modified polymers EHEC–1 and SBX–1, respectively. Films were obtained and the resulting materials were used as fluorogenic devices for the detection of Hg2+ in water. The films produced from EHEC–1 showed high water retention, making it difficult to apply as a reusable optical chemosensor. Since SBXs are recognized in the literature for their hydrophobicity, a hybrid film composed of EHEC and SBX–1 which did not show water retention was produced and characterized. This system showed rapid response time, outstanding selectivity compared to several other studied metal ions, and sensitivity for the detection of Hg2+ in water. The detection limit for this material using fluorescence technique was 2 ppb (∼10−8 mol L−1). The reversibility of the complex formed between EHEC-SBX–1 film and Hg2+ was demonstrated by the addition of cysteine to the medium. The result obtained also allowed the assembly of INHIBIT and IMPLICATION molecular logic gates, using Hg2+ and cysteine as inputs. The results described in this article have important significance in the development of novel reversible fluorogenic chemosensors and adsorbent materials for the effective removal of Hg2+ ions.

A sensitive ratiometric fluorescent chemosensor for visual and wearable mercury (II) recognition in river prawn and water samples

A novel ratiometric fluorescent probe p-RPT was prepared with triphenylamine and a rhodamine derivative. The probe displays high sensitivity and selectivity for Hg2+, which was applied in real water sample detection and biologic cell imaging. Hydrogel-coated paper sensors were fabricated with p-RPT, which displayed fluorescent colour change upon Hg2+ ion contact with a detection limit of 1.2 × 10-8 M (∼10 ppb). In addition, flexible fluorescent p-RPT gloves were developed for visible and wearable Hg2+ detection and applied to detect mercury (II) in river prawn samples. In summary, the p-RPT probe not only shows great potential in mercury (II) detection for food and water, but also provides a new perspective for wearable sensing apparatus.

A difunctional electrochemiluminescence sensor based on Ru-MOFs and strand-displacement-amplification reaction for ultrasensitive detection of Hg2+ and Ag+

A label free difunctional electrochemiluminescence (ECL) sensor for the ultrasensitive detection of mercury ions (Hg2+) and silver ions (Ag+) was constructed based on Ru(bpy)32+-functionalized metal-organic frameworks (Ru-MOFs) and the strand-displacement-amplification (SDA) reaction. Electrodeposited Ru-MOFs not only overcome the disadvantage of poor stability of traditional Ru2+ in aqueous solution, but also serve as an excellent carrier for hairpin DNA H1 during sensor construction. The SDA technology can transform extremely low concentrations of Hg2+ and Ag+ into a large number of the same alternative target DNA (tDNA). By combining SDA with Ru-MOFs, the detection sensitivity of the sensor is further improved. Meanwhile, the generated same alternative target tDNA can realize the detection of Hg2+ and Ag+ ions on this same sensing platform, which is beneficial to solve the common problems of high cost, long time and complicated operation in the detection of metal ion. The detection limits for Hg2+ and Ag+ are as low as 0.00032 pM and 0.00298 pM, respectively. And the corresponding linear detection range (LDR) is 0.001–1000 pM and 0.01–10000 pM, respectively. This ECL sensor has also been successfully used in the determination of Hg2+ and Ag+ in seawater, indicating an ideal platform for the simultaneous detection of trace heavy metal ions.

A single-stranded DNA-based and terbium (III) fluorescent probe for facile and rapid detection of mercury (II)

Hg2+, as a highly dangerous pollutant, seriously affects public health and food safety. In this work, a biosensor based on single-stranded DNA and Tb3+ fluorescent probe was constructed for facile and rapid detection of Hg2+. The detection method only needs one DNA strand, which consists of two parts: the G-rich sequence is the Tb3+ luminescent antenna ligand and the T-rich sequence is the Hg2+ recognition probe. Free mercury-specific DNA (MSD) in an aqueous solution could significantly enhance Tb3+ luminescence. Upon the addition of Hg2+, the conformation of MSD will switch from the free random coil structure to the hairpin structure. Thus, Tb3+ was released and the fluorescence of Tb3+ was decreased. After condition optimization, the change of fluorescence intensity was proportional to the logarithmic concentration of Hg2+ from 0.01 to 10 μM with a detection limit of 1.9 nM. In addition, the detection results of Hg2+ in real samples were satisfactory. The designed fluorescent probe has great advantages in simplicity and functionality and has great development potential in food safety and environmental pollution.

Simultaneous detection of copper and mercury in water samples using in-situ pH control with electrochemical stripping techniques

The performance of electrochemical sensors using an in situ pH control technique for detection of mercury and copper in neutral solutions is described herein. Sensors are comprised of two distinct parallel gold interdigitated microband electrodes each of which may be polarised separately. Biasing one interdigitated “protonator” electrode sufficiently positive to begin water electrolysis, resulted in the production of H+ ions, which, consequently droped the interfacial pH at the other second interdigitated “sensing” electrode. This decrease in pH permitted the electrodeposition (and consequent stripping) of metals at a sensing electrode without the need to acidify the whole test solution. In this work, the local pH could be adjusted in the acidic pH range in a stable and reproducible way just by tailoring the polarization of the protonator electrode. Using this approach, a linear range for copper 5 to 100 ppb and for mercury 1 to 75 ppb were obtained. The sensors also have an extremely high sensitivity for the metals. The in-situ pH control, coupled with electrochemical stripping, allowed metal detection in a complex water matrix, e.g., river water without the need for sample pre-treatment. The electrochemical results were confirmed by comparison to those obtained using inductively coupled plasma – optical emission spectroscopy. A very good agreement was observed between both sets of results. The electrode reproducibility was high (RSD < 10%) and the metals could be co-detected simultaneously. Thus, this work shows a fast and easy approach for in-situ pH control for multi metal detection using solid state sensors.

Silica–silver core–shell nanoparticles incorporated with cellulose filter paper as an effective colorimetric probe for mercury ion detection in aqueous media: Experimental and computational evaluations

This study investigates the facile and rapid detection of mercury ions using silica–silver core–shell nanoparticles (SiO2–AgNPs) incorporating a paper-based colorimetric sensor strip. A strong surface plasmon resonance peak at λ = 430 nm was observed for the resultant SiO2–AgNPs. The attachment of the AgNPs to the surface of SiO2 and the deposition of the AgNPs on the paper strip were confirmed using an electron microscope. The sensing of the SiO2–AgNPs toward the mercuric ion (Hg2+) in an aqueous solution indicated a rapid response in terms of a color change from yellowish-brown to colorless with a response time of 5–10 s. The prepared SiO2–AgNPs deposited on the paper strip exhibited high selectivity toward Hg2+ compared with other metal ions. The limit of detection for this assay was 1.13 nM, with an excellent correlation value of R2 = 0.9936. In addition, the complexation mode of the SiO2–AgNPs with Hg2+ was also elucidated via theoretical calculations using the density functional theory approach. This approach also provides insight into the complexation structure in terms of the electronic alteration of the SiO2–AgNPs prior to and following their interaction with Hg2+. Overall, the study demonstrates that SiO2–AgNP-based sensor materials can be utilized for the selective recognition of Hg2+ in aqueous solutions.

The synthesis of SBA-Pr-N-Is-Bu-SO3H as a new Hg2+ fluorescent sensor

• Isatin‐based fluorescent chemosensor was synthesized. • SBA-15 with (3-aminopropyl)triethoxysilane, followed by functionalized with isatin and 1,4-butane sultone to achieve SBA-Pr-N-Is-Bu-SO 3 H. • The compound was tested by FT-IR, EDX, SEM, BET, and TGA techniques. • The fluorescence spectroscopy of the obtained used as a Hg 2+ ion chemosensor. Isatin‐based fluorescent chemosensor was synthesized by the treatment of mesoporous SBA-15 with (3-aminopropyl)triethoxysilane, followed by functionalized with isatin and 1,4-butane sultone to achieve SBA-Pr-N-Is-Bu-SO 3 H. The compound was tested by FT-IR, EDX, SEM, BET, and TGA techniques. In addition, the fluorescence spectroscopy of the obtained nanomaterial (SBA-Pr-N-Is-Bu-SO 3 H) demonstrated that it could be used as a Hg 2+ ion chemosensor shown high selectivity in aqueous media, and its detection limit was calculated 2.5 × 10 −6 M. It was confirmed an active method for detecting mercury ion selectivity of fluorescence sensors.

Luminescent Pyrene-based Schiff base Receptor for Hazardous Mercury(II) Detection Demonstrated by Cell Imaging and Test Strip.

Qualitative and quantitative analysis of mercury at concentration levels as low as parts per billion (ppb) is a basic and practical concern. The vast majority of research in this field has centered on the development of potent chemosensor to monitor mercuric (Hg2+) ions. Mercury exists in three oxidation states, + 2, + 1 and 0, all of which are highly poisonous. In this study, (N1E,N2E)-N1,N2-bis(pyrene-1-ylmethylene)benzene-1,2-diamine (PAPM), a novel photoluminescent sensor based on pyrene platform was synthesized. Over the tested metal ions (Cd2+, Co2+, Cu2+, Mg2+, Mn2+, Ni2+, K+, Na+, Zn2+, Sr2+, Pb2+, Al3+, Cr3+ and Fe3+) the sensor responds only to Hg2+ by showing high selectivity and sensitivity. After treatment with mercuric ions at room temperature, the luminescence intensity of probe was quenched at 456nm. The quenching of fluorescence intensity of probe upon addition of mercury is due to the effect of "turn-off" chelation enhanced quenching (CHEQ) by the formation of 1:1 complex. The ESI-MS spectrum and the Job's experimental results confirm the formation of 1:1 complex between PAPM and Hg2+. The detection limit and association constant of sensor for mercury is computed using fluorescence titration data and were found to be 9.0 × 10-8M and 1.29 × 105M-1 respectively. The practical application of sensor towards recognition of mercury(II) ions was explored through economically viable test strips and also using cell imaging studies.

Development of Machine Learning-based system for mercury (Hg) detection

The existence of hazardous chemicals and pollutants in water is one of many societal concerns. This water when consumed or used for some specific domestic or industrial purposes brings about apprehension regarding health-related consequences. Thisworkexplores the capability ofa machine learning-based systemin detecting the presence of heavy metals like Mercury (Hg) in water. It demonstratesnear-accurate concentration predictionin the range of 0.001mg/liter to 100mg/liter using a voting regressor. Implementation of the system is done by integrating a camera with Raspberry-pi, programmed to detect the presence of metals with its concentration and usability.Datasetwas prepared for training our model considering the different concentrations of reagents and water samples.Thissystem demonstrates a good capability to predict the concentration of heavy metals along with its usage recommendations

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.

Bismuth-Based BiOBrxI1–x/Ti3C2 MXene Schottky Nanocomposites for Hg2+ Photoelectrochemical Sensors

BiOBrxI1–x/Ti3C2 Schottky heterojunction nanocomposites were prepared through a simple electrostatic adsorption and self-assembly method. The Schottky heterojunction was used as a sensitive material in the fabrication of a photoelectrochemical (PEC) sensor for mercury ion detection. Due to the large specific surface area, excellent electrical conductivity, and abundant surface chemical groups of the 2D nano Ti3C2 in the Schottky heterojunction, the in situ growth of solid solution BiOBrxI1–x on its surface enabled the nanocomposites to form a high Schottky barrier to improve the sensitivity of the PEC response. The addition of glutathione (GSH) caused it to adhere to the surface of the nanocomposites where it hindered the transfer of electrons and reducing the photocurrent by reacting with the bismuth ions on their surface through its carboxyl groups. During the Hg2+ assay, Hg2+ ions reacted to GSH on the surface of the heterojunction nanocomposites, and then captured more GSH in a solution to form a complex with 3D structure. This complex further hindered electron transfer and led to a sharp decrease in photocurrent. A trace amount of Hg2+ was detected based on the change of photocurrent, with a linear range of 1.0 × 10–10 mol/L to 1.0 × 10–6 mol/L and a detection limit of 4.21 × 10–11 mol/L. This method was one of the most sensitive methods reported for Hg2+ detection. The sensor had been applied to determine trace mercury in environmental water samples.

Rational design of diphenyl-λ5σ4-phosphinine based fluorescent probe for the selective detection of Hg2+ ions: Real application in cell imaging and paper strips

Due to its great toxicity to the bio-aquatic environment, developing highly selective and sensitive probes for the detection of mercury ions in solutions as well as in living cells is a major problem. To detect Hg2+ ions in organic semi-aqueous solutions, we created a fluorescent probe called 4-(1, 3-dithian-2-yl)-1,1-diphenyl- λ5-phosphinine-2,6-dicarbonitrile (DDPD) with optical behaviour. Through the Hg2+-promoted deprotection process of thioacetals, which was followed by considerable changes in fluorescence colour and spectral pattern, the probe DDPD selectively detected Hg2+ ions in a broad pH range with a detection limit of 56 nM. Specifically, DDPD can be used to qualitatively identify Hg2+ ions using test strips made of Whatman filter paper and also in HeLa cells it can identify Hg2+ ions and image them using fluorescent microscopy.

A Coumarin-azo Derived Colorimetric Chemosensor for Hg2+ Detection in Organic and Aqueous Media and its Extended Real-world Applications.

Pollution caused by the release of toxic heavy metals into the environment by industrial and farming processes has been regarded as a major problem worldwide. This has attracted a great deal of attention into restoration and remediation. Mercury is classified as a toxic heavy metal which has posed significant challenges to public and environmental health. To date, conventional methods for mercury detection rely on expensive, destructive, complex, and highly specialized methods. Evidently, there is a need to develop systems capable of easily identifying and quantifying mercury within the environment. In this way, organic-based colorimetric chemosensors are gaining increasing popularity due to their high sensitivity, selectivity, cost-effectiveness, ease of design, naked-eye, and on-site detection ability. The formation of coumarin-azo derivative AD1 was carried out by a conventional diazotization reaction with coumarin-amine 1c and N,N-dimethylaniline. Sensor AD1 displayed remarkable visual colour change upon mercury addition with appreciable selectivity and sensitivity. The detection limit was calculated as 0.24µM. Additionally, the reversible nature of AD1 allowed for the construction of an IMPLICATION type logic gate and Molecular Keypad Lock. Chemosensor AD1 displayed further sensing applications in real-world water samples and towards on-site assay methods. Herein, we describe a coumarin-derived chemosensor bearing an azo (N = N) functionality for the colorimetric and quantitative determination of Hg2+ in organic and aqueous media.

Fabrication of novel copper MOF nanoparticles for nanozymatic detection of mercury ions

Mercury (II) ions are considered the most harmful heavy metal ion and their accumulation in the human body causes several diseases so need to be detected at trace levels. The use of nanozyme-based colorimetric detection is an acknowledged and innovative method to detect heavy metal ions in water bodies. In this work, we report CuMOF nanoparticles (CuMOF NPs) synthesized using hand grinding technique. The MOF nanoparticles were characterized by FTIR, TGA, SCXRD, PXRD, FESEM and TEM. The SCXRD confirmed paddle wheel type structure and MOF exhibits interpenetrated pcu topology with point symbol {412.63}. BET analysis revealed a high surface area of 15.995 m2g-1 and pore diameter of 3.42 nm for CuMOF NPs. The MOF NPs were found to show peroxidase-like activity. The CuMOF NPs employed as the catalyst, where 3,3′,5,5′-tetramethylbenzidine (TMB) was oxidised by Hg2+ and a bluish solution of oxidised TMB was obtained and recorded by UV–vis spectroscopy. The activity was determined with a detection limit of 0.55 μM, Km of 0.0477 M, and Vmax of 0.3125 M s−1 for TMB, and Km of 2.646 M and Vmax of 0.126 M s−1 for H2O2. The selectivity of the method was excellent and the mechanism was supported by XPS analysis. So, we provide a low-cost, eco-friendly approach for the detection of Hg2+ using CuMOF NPs.

2D-layered Bi-functional direct solid-Z-scheme heterogenous vanadium and oxygen doped graphitic carbon nitride single layered nanosheet catalysis for detection and photocatalytic removal of toxic heavy metal

In this Research, the “Get the two Mangoes with one stone” strategy was utilized to investigate the electrochemical detection and photocatalytic removal of mercury ions (Hg2+) using vanadium pentoxide doped graphitic carbon nitride (V2O5/gCN) nanosheets for the first time. The proposed materials can be better choice for environmental issues. In this research, a novel direct Z-scheme V2O5/gCN nanosheets were prepared through direct thermal decomposition techniques with the different (0.1–0.5 wt%) weight ratios of dopant materials. The prepared nanosheets physiochemical properties can be obtained through various characterizations techniques. Moreover, the prepared nanosheets exhibit an excellent electrochemical ability for the detection of Hg2+ ions with a limit of detection is 9.2 nM, linear range from 0.2 to 100 μM, and enormous sensitivity (9.9857 μA μM−1 cm−2), respectively. Furthermore, the higher photocatalytic removal efficiency was obtained in this optimized dopant (0.2 wt%) concentration of V2O5-doped gCN nanosheets. In addition, the complete removal was obtained within a short treatment time under the visible light irradiation. Furthermore, the target (Hg2+) ions removals are quantified by ICP-OES, and quantification values were found to be 2762 ppm and 101 ppm before and after treatments, respectively. Therefore, this research work will be beneficial for the design of direct Z-scheme photo-electrocatalytic systems for application in real-time detection and environmental remediation.

Rapid Detection of Mercury Ions Using Sustainable Natural Gum-Based Silver Nanoparticles

Fabrication of metal nanostructures using natural products has attracted scientists and researchers due to its renewable and environmentally benign availability. This work has prepared an eco-friendly, low-cost, and rapid colorimetric sensor of silver nanoparticles using tree gum as a reducing and stabilizing agent. Several characterization techniques have been exploited to describe the synthesized nanosensor morphology and optical properties. Ultraviolet−Visible (UV−Vis) spectroscopy has been used for monitoring the localized plasmon surface area. High-resolution transmission electron microscopy (HR-TEM) illustrated the size and shape of silver nanoparticles. X-ray diffraction spectra showed the crystallography and purity of the product. Silver nanoparticles decorated with almond gum molecules (AgNPs@AG) demonstrated high sensitivity and colorimetric detection of mercury ions in water samples. The method is based on the aggregation of AgNPs and the disappearing yellow color of AgNPs via a spectrophotometer. The detection limit of this method was reported to be 0.5 mg/L. This work aimed to synthesize a rapid, easy-preparation, eco-friendly, and efficient naked-eye colorimetric sensor to detect toxic pollutants in aqueous samples.

A novel peptide fluorescent probe based on different fluorescence responses for detection of mercury species and hydrogen sulfide

Mercury species, including inorganic and organic mercury, are extremely harmful to organisms and the environment. Therefore, it is of great significance to rapidly and selectively detect and distinguish inorganic mercury ions and organic mercury. This study reports peptide sequences that can act as inorganic mercury ions and organic mercury ligands. The peptide fluorescent probe KEEP ((Dansyl-Glu-Glu)2-Lys-NH2) can detect mercury species by its coordination with the side chain of glutamic acid. Hg2+ can be detected by the “turn-off” fluorescence mode, while CH3Hg+ and PhHg+ can be detected by the “turn-on” fluorescence mode. This probe with different fluorescence response to inorganic and organic mercury is very rare, which makes it possible to distinguish between Hg2+, CH3Hg+ and PhHg+. KEEP-Hg2+ can also detect hydrogen sulfide (H2S) through fluorescence reproduction. KEEP can detect these three analytes without interference from other substances due to excellent selectivity. KEEP also has good biocompatibility and low biotoxicity, and can successfully monitor the accumulation of Hg2+ and S2- in living cells. This probe provides a new approach for the detection of inorganic mercury and organic mercury.