Detection Of Heavy Metals Research Articles

A Graphene Gold Metasurface Inspired Surface Plasmon Resonance Sensor Designed for Terahertz Applications in Sensing and Detection of Heavy Metals in Water

A Graphene Gold Metasurface Inspired Surface Plasmon Resonance Sensor Designed for Terahertz Applications in Sensing and Detection of Heavy Metals in Water

Ultrasensitive electrochemical sensors based on Cu and Cu@Ag nanorods for simultaneous heavy metal detection

This work reports the development of ultrasensitive miniaturized electrochemical device for heavy metal sensing. A laser engraver based patterning of fluorine-doped tin oxide (FTO) sheet was done to draw an etched pattern forming a miniaturized 3-electrode configuration. A layer of Ag/AgCl ink served as pseudo-reference electrode. The sensing electrode was coated using low-cost Cu nanorods (CuNRs) grown radially along the {110} surface with aspect ratio of 8.0 and Cu@Ag core-shell nanorods (Cu@AgNRs) formed via galvanic displacement for simultaneous electrocatalytic detection of heavy metal ions (Pb(II), Cd(II), Hg(II), and Zn(II)) present in water. The electroactive surface area of the prepared devices is 0.026, 0.093 and 0.125 cm2 for bare FTO, CuNRs/FTO and Cu@AgNRs/FTO, respectively. Bimetal Cu@AgNRs/FTO sensor exhibited the lowest limit of detection of 1, 2, 5 and 6 nM, respectively, detecting Cd(II), Pb(II), Zn(II), and Hg(II) ions, and it was 2, 2, 3 and 4 nM, respectively, for simultaneous detection of Zn(II), Pb(II), Cd(II) and Hg(II). The Cu@AgNRs/FTO based device showed distinct peak-to-peak separation by 0.40, 0.25 and 0.51 V for Zn(II)-Cd(II), Cd(II)-Pb(II) and Pb(II)-Hg(II), respectively. This device was highly sensitive (583.6–1261.8 μA․μM−1․cm−2) for heavy metal detection over CuNRs/FTO (15.9–107.4 μA․μM−1․cm−2). The Cu@AgNRs/FTO based sensors demonstrated good reproducibility (relative standard deviation ≤ 5%) with recovery (>90%) in the case of all target heavy metals simultaneously present in environmental water samples. Hence, the Cu nanorods based miniaturized sensing platforms developed in the present study for simultaneous heavy metal detection are potential low-cost alternatives providing a repeatability of upto 4 cycles unlike the commercial screen-printed electrodes.

Simultaneous and on-line detection of organic and heavy metal components in water using a novel nebulization-assisted injection plasma ionization triple quadruple mass spectrometry instrument

BackgroundThe global release of organic and heavy metal components into natural water bodies is a major concern for the environment and human health. The assessment of water quality relies on analyzing organic and heavy metal components qualitatively and quantitatively. Real-time identification of organic and metal components in water systems requires different analytical techniques due to varying measurement requirements. Thus, on-line detecting both organic compounds and heavy metals in ambient water systems simultaneously using a single instrumentation setup presents a significant challenge. ResultsIn this study, an analytical technique of nebulization-assisted injection plasma ionization mass spectrometry (NI-PIMS) was developed. This novel method enables the simultaneous detection of heavy metals and organic compounds in water system with high sensitivity, which has been demonstrated by the limit of quantification (LOQ) values below 1.0 μg/L for the three sterols (Enrofloxacin, ciprofloxacin, and clenbuterol) and three heavy metals (Pb, Ba, and Cd). Moreover, the method was successfully applied to rapidly analyze real water samples from urban and rural areas in China. The analytical results are available in less than 0.5 min, and only a few microliters of sample are required for each analysis. Significance and noveltyAs far as we know, this is the first report of on-line simultaneous analysis of organic compounds and heavy metals in a water system using a single mass spectrometry instrument. Compared to traditional methods, NI-PIMS demonstrates higher efficiency, sensitivity, no or lower sample preparation, and less sample consumption. The advancement and widespread use of this technology are expected to enhance the effectiveness of mass spectrometers, broaden the applications, and play an important role in complex sample analysis in fields such as atmospheric science, environmental science, and earth science.

Improved Microelectrode Array Electrode Design for Heavy Metal Detection

Traditional working electrodes are not sufficient to realize the low detection limit and wide detection range necessary for the detection of heavy metals. In this study, a microelectrode array electrode was proposed using a design scheme based on microelectromechanical systems that was optimized with finite element software. The working electrode adopted an innovative composite structure to realize the integrated design of the working and counter electrodes, which improved the system integration. Performance tests showed that the electrode realized the quantitative analysis of Cd(II), Pb(II), and Cu(II) with a low detection limit (0.1 μg/L) and a wide detection range (0.1–3000 μg/L). The electrode successfully measured the lead and copper ion concentrations in the Sanya River, including both seawater and freshwater environments. The experimental results demonstrate that the electrode exhibits excellent adaptability to environmental conditions and can be potentially applied for technical support in environmental monitoring and sewage treatment.

Research of MXenes and Their Applications in Sensors and Batteries

MXene, a novel two-dimensional material class, demonstrates significant potential across diverse applications such as electrochemical heavy metal detection, pressure sensor active material, and sodium battery composites. MXene-based sensors, in the realm of heavy metal detection, exhibit high sensitivity and selectivity, which are vital in monitoring and controlling environmental pollution. These sensors utilize MXene's distinct conductive and surface properties, facilitating efficient and precise detection of heavy metals, including lead, mercury, and cadmium. In pressure sensors, MXene contributes to enhanced performance owing to its superior electrical conductivity and mechanical strength, allowing the creation of sensitive and robust sensors apt for cutting-edge applications in robotics, wearable technology, and IoT devices. Furthermore, MXene composites in sodium batteries lead to improved battery performance in energy storage. The high conductivity and electrochemical stability of MXene, coupled with its sodium ion hosting capability, render it an optimal material for boosting sodium battery capacity and cyclability. This progress holds immense importance in developing sustainable and efficient energy storage solutions. MXene's versatility and exceptional attributes continue to propel innovation in various fields, including environmental monitoring, energy storage, and sensor technology.

The Multifaceted Perspective on the Role of Green Synthesis of Nanoparticles in Promoting a Sustainable Green Economy

The current economic development paradigm, which is based on steadily rising resource consumption and pollution emissions, is no longer viable in a world with limited resources and ecological capacity. The “green economy” idea has presented this context with a chance to alter how society handles the interplay between the environmental and economic spheres. The related concept of “green nanotechnology” aims to use nano-innovations within the fields of materials science and engineering to generate products and processes that are economically and ecologically sustainable, enabling society to establish and preserve a green economy. Many different economic sectors are anticipated to be impacted by these applications, including those related to corrosion inhibitor nanofertilizers, nanoremediation, biodegradation, heavy metal detection, biofuel, insecticides and pesticides, and catalytic CO2 reduction. These innovations might make it possible to use non-traditional water sources safely and to create construction materials that are enabled by nanotechnology, improving living and ecological conditions. Therefore, our aim is to highlight how nanotechnology is being used in the green economy and to present promises for nano-applications in this domain. In the end, it emphasizes how critical it is to attain a truly sustainable advancement in nanotechnology.

Electrochemical detection of heavy metal ions in water using MWCNT/ZnO nanocomposite

A nanocomposite of multi-walled carbon nanotubes (MWCNTs) decorated with zinc oxide nanoparticles (ZnO NPs) was fabricated via an in-situ hydrothermal approach and implemented as a modified electrode for stripping voltammetric detection of dissolved heavy metal ions. The MWCNT/ZnO exhibited a high specific surface area of 53 m2/g and charge transfer conductivity amplified to 26 S/cm. By square wave voltammetry, the nanocomposite sensor achieved wide linear detection of Cu(II) from 1 to 800 ppb, Pb(II) from 5 to 1000 ppb, and Hg(II) from 1 to 900 ppb, along with low limits of detection reaching 0.8, 1.2, and 0.7 ppb, respectively. The 3–5X enhanced sensitivity versus an unmodified screen-printed carbon electrode confirms performance gains supplied by the tailored hybrid interface. Selectivity testing produced distinct, well-resolved oxidation peaks for each metal ion target that remained unaffected by high off-target concentrations of Mn(II), Co(II), and Fe(III) interferents. Accurate spike recoveries between 95% and 102% were obtained from quantifying ternary mixtures across various Cu(II):Pb(II):Hg(II) compositions, substantiating the capability for simultaneous multianalyte analysis. The simple preparation, high sensitivity and selectivity, and accuracy for direct water testing validates the nanocomposite as a practical portable sensor for on-site toxic heavy metal detection.

Heteroatoms-doped carbon dots as dual probes for heavy metal detection

The utilization of l-cysteine in hydrothermal synthesis allows for the manufacture of carbon dots (CDs) that are doped with heteroatoms including oxygen, nitrogen, and sulfur (N, S, O-doped CDs). CDs have a particle size ranging from 1 to 3 nm, with an average particle size of 2.5 nm. N, S, and O-doped CDs display a blue fluorescence emission at a wavelength of 425 nm. It shows a reliance on the specific excitation wavelength between 320 and 500 nm. It has a selective quenching effect specifically with copper (Cu2+) ions when exposed to interactions with heavy metal ions, as compared to other metal ions. The assay has a limit of detection (LOD) of 2 μM and exhibits a linear correlation within the concentration range of 10–33.3 μM. The fluorescence mechanism was elucidated by employing various analytical techniques, such as transmission electron microscopy (TEM), high-resolution TEM , UV–Vis spectroscopy, zeta potential analysis, and conductometry. An analysis of the data reveals that Cu2+ ions exhibit a strong attraction to the external surface of N, S, and O-doped CDs, leading to the formation of aggregates. N, S, and O-doped CDs can be also used as probes for electrochemical investigations utilizing cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) to produce Nyquist and Bode plots. The electrochemical results offer substantiation for the interaction between Cu2+ ions and N, S, and O-doped CDs. Zero-dimensional carbon nanomaterials, i.e. CDs, can improve the detection of heavy metals using optical and electrochemical methods.

A novel electrode for simultaneous detection of multiple heavy metal ions without pre-enrichment in food samples

Integrating a pre-enrichment step into electrochemical detection methodologies has traditionally been employed to enhance the performance of heavy metal detection. However, this augmentation also introduces a degree of intricacy into the sensing process and increases energy consumption. In this work, Mo-doped WO3 is grown in situ on carbon cloth by one-step electrodeposition. The electrode detect multiple heavy metal ions simultaneously in the range of 0.1–100.0 μM with LODs ranging from 11.2 to 17.1 nM. The electrode successfully detected heavy metal ions in diverse food samples. This pioneering detection strategy realized the direct and simultaneous detection of multiple heavy metal ions by utilizing the valence property of WO3 and oxygen vacancies generated by molybdenum doping. The Mo-WO3/CC pre-enrichment-free detection electrode boasts straightforward preparation, a streamlined detection procedure, swift response kinetics, and superior performance relative to previously reported electrodes, which makes it possible to develop a portable heavy metal ion detection device.

Extremozyme-Based Biosensors for Environmental Pollution Monitoring: Recent Developments.

Extremozymes combine high specificity and sensitivity with the ability to withstand extreme operational conditions. This work presents an overview of extremozymes that show potential for environmental monitoring devices and outlines the latest advances in biosensors utilizing these unique molecules. The characteristics of various extremozymes described so far are presented, underlining their stability and operational conditions that make them attractive for biosensing. The biosensor design is discussed based on the detection of photosynthesis-inhibiting herbicides as a case study. Several biosensors for the detection of pesticides, heavy metals, and phenols are presented in more detail to highlight interesting substrate specificity, applications or immobilization methods. Compared to mesophilic enzymes, the integration of extremozymes in biosensors faces additional challenges related to lower availability and high production costs. The use of extremozymes in biosensing does not parallel their success in industrial applications. In recent years, the "collection" of recognition elements was enriched by extremozymes with interesting selectivity and by thermostable chimeras. The perspectives for biosensor development are exciting, considering also the progress in genetic editing for the oriented immobilization of enzymes, efficient folding, and better electron transport. Stability, production costs and immobilization at sensing interfaces must be improved to encourage wider applications of extremozymes in biosensors.

Chemically Functionalized 2D Transition Metal Dichalcogenides for Sensors.

The goal of the sensor industry is to develop innovative, energy-efficient, and reliable devices to detect molecules relevant to economically important sectors such as clinical diagnoses, environmental monitoring, food safety, and wearables. The current demand for portable, fast, sensitive, and high-throughput platforms to detect a plethora of new analytes is continuously increasing. The 2D transition metal dichalcogenides (2D-TMDs) are excellent candidates to fully meet the stringent demands in the sensor industry; 2D-TMDs properties, such as atomic thickness, large surface area, and tailored electrical conductivity, match those descriptions of active sensor materials. However, the detection capability of 2D-TMDs is limited by their intrinsic tendency to aggregate and settle, which reduces the surface area available for detection, in addition to the weak interactions that pristine 2D-TMDs normally exhibit with analytes. Chemical functionalization has been proposed as a consensus solution to these limitations. Tailored surface modification of 2D-TMDs, either by covalent functionalization, non-covalent functionalization, or a mixture of both, allows for improved specificity of the surface-analyte interaction while reducing van der Waals forces between 2D-TMDs avoiding agglomeration and precipitation. From this perspective, we review the recent advances in improving the detection of biomolecules, heavy metals, and gases using chemically functionalized 2D-TMDs. Covalent and non-covalent functionalized 2D-TMDs are commonly used for the detection of biomolecules and metals, while 2D-TMDs functionalized with metal nanoparticles are used for gas and Raman sensors. Finally, we describe the limitations and further strategies that might pave the way for miniaturized, flexible, smart, and low-cost sensing devices.

Detection of Cadmium and Lead Heavy Metals in Soil Samples by Portable Laser-Induced Breakdown Spectroscopy

Heavy metal pollution in soil is becoming more and more serious. LIBS is one of the most promising technologies for rapid detection of heavy metal contamination in soil. However, due to the wide variety of soils and complex matrices, accurate quantification remains a challenge. In total, 451 soil samples were prepared and detected by the portable detector of LIBS, which were divided into six categories based on the compactness of the soil pellets, and a separate quantitative model for each type of soil sample was used for quantitative analysis by external standard method. It did not need a lot of data to train the model, and only a small number of calibration samples could be used for quantitative analysis of a large number of samples. The results showed that 78 standard samples and 334 collected samples were quantitatively analyzed by 39 standard samples. Compared with the standard value, the correlation coefficients were all above 0.95. A comparative experiment indicated that the portable LIBS system combined with soil classification and calibration methods can achieve fast and accurate quantitative detection.

Visual self-powered platform for ultrasensitive heavy metal detection designed on graphdiyne/graphene heterojunction and DNAzyme-triggered DNA circuit strategy

Self-powered electrochemical biosensors based on enzyme biofuel cells (EBFC) are uniquely valuable in developing real-time and on-site detection of heavy metal ions. This work combines graphdiyne/graphene (GDY/GR) heterojunction with Deoxyribozyme (DNAzyme) trigger catalytic hairpin self-assembly (CHA) circuit. In addition, the smartphone is introduced to obtain the detection signals. The results show that the designed sensor platform can be used for single-tube ultrasensitive and visual lead ion detection with a wide linear range of 0.003–5000 nM and a low detection limit (LOD) of 0.005 nM. This design enriches the routine screening methods for heavy metal ions in food and environmental samples and introduces new idea for the development and application of self-powered electrochemical biosensors.

Detection and quantification of heavy metals and minerals in poultry feed collected from selected local markets in Bangladesh.

The study was primarily conducted to assess the stakeholders' knowledge regarding the contamination caused by heavy metals in poultry feedstuffs. The concentration of some heavy metals (lead, chromium, cadmium, and nickel) and macro-minerals (sodium, potassium, and calcium) was also analyzed in poultry feeds collected from selected local markets in Sherpur district, Bangladesh. A well-structured questionnaire survey was used to investigate different stakeholders' perspectives in relation to metal contamination in feed. Heavy metals and calcium were determined by atomic absorption spectrophotometry. The flame emission spectrophotometric technique was applied to determine sodium and potassium. The majority of the stakeholders (90%) were found to have no knowledge regarding heavy metal contamination. Lead and nickel concentrations were below the detectable level in the collected samples. The average concentration of chromium in Jhenaigati upazila was four times higher than in Nalitabari upazila, at 21.806 mg kg-1 and 5.452 mg kg-1, respectively. The concentrations of cadmium in both brand and nonbrand samples exceeded the maximum allowable limit set by the European Union at 1.329 mg kg-1 and 1.328 mg kg-1, respectively. Sodium, potassium, and calcium were found in the ranges of 0.0011%-0.0035%, 0.0010%-0.0013%, and 0.0080%-0.0305%, which were extremely low in concentration compared to the minimum requirement in poultry feed. Regular surveillance and governance systems should be incorporated into national policy to cease the hazardous impacts of heavy metals through feed contamination. From a nutritional viewpoint, poultry feeds need to be critically formulated.

Rapid and sensitive in situ detection of heavy metals in fish using enhanced Raman spectroscopy

Heavy metals have been widely applied in industry, agriculture, and other fields because of their outstanding physics and chemistry properties. They are non-degradable even at low concentrations, causing irreversible harm to the human and other organisms. Therefore, it is of great significance to develop high accuracy and sensitivity as well as stable techniques for their detection. Raman scattering spectroscopy and atomic absorption spectrophotometer (AAS) were used parallelly to detect heavy metal ions such as Hg, Cd, and Pb of different concentrations in fish samples. The concentration of the heavy metals is varied from 5 ppb to 5 ppm. Despite the satisfactory recoveries of AAS, their drawbacks are imperative for an alternative technique. In Raman scattering spectroscopy, the intensities and areas of the characteristic peaks are increased with increasing the concentration of the heavy metals. For Hg concentration ≥ 1 ppm, a slight shift is observed in the peak position. The obtained values of peak intensity and peak area are modeled according to Elvoich, Pseudo-first order, Pseudo-second order, and asymptotic1 exponential model. The best modeling was obtained using the Elovich model followed by the asymptotic1 exponential model. The introduced Raman spectroscopy-based approach for on-site detection of trace heavy metal pollution in fish samples is rapid, low-cost, and simple to implement, increasing its visibility in food safety and industrial applications.

Heavy metal sensing in plant and soil solutions using carbon fiber electrode

Analysis of trace level metals in environmental samples (e.g., soil, water, and plant samples) is important for assessing environmental quality and food safety. This paper reports a non-toxic, eco-friendly, and cost-effective sensing method, capable of in-situ detection of microgram per liter (µg/L) levels of heavy metal ions in plant and soil solutions using carbon fiber electrodes (CFEs) produced without using any microfabrication. The electrochemical behaviors of the CFEs were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements. As proof of principle, the CFEs were validated for sensing selected heavy metals in buffer solutions as well as in extracted plant and soil solutions using differential pulse anodic stripping voltammetry (DP-ASV). Experimental results confirm that the CFEs were able to simultaneously measure cadmium (Cd), lead (Pb), and mercury (Hg) with a detection limit of 2.10, 0.93, and 1.85 µg/L respectively in buffer solution, showcasing good selectivity and sensitivity. The ideal pH range for heavy metal detection was also extensively investigated and was found to be between pH 4.0 and pH 5.0. These findings lay a better foundation towards long-term and stable electrochemical analysis for plant and soil solution matrices.

Artificial intelligence and machine learning algorithms in the detection of heavy metals in water and wastewater: Methodological and ethical challenges

Heavy metals (HMs) enter waterbodies through various means, which, when exceeding a threshold limit, cause toxic effects both on the environment and in humans upon entering their systems. Recent times have seen an increase in such HM influx incident rates. This requires an instant response in this regard to review the challenges in the available classical methods for HM detection and removal. As well as provide an opportunity to explore the applications of artificial intelligence (AI) and machine learning (ML) for the identification and further redemption of water and wastewater from the HMs. This review of research focuses on such applications in conjunction with the available in-silico models producing worldwide data for HM levels. Furthermore, the effect of HMs on various disease progressions has been provided, along with a brief account of prediction models analysing the health impact of HM intoxication. Also discussing the ethical and other challenges associated with the use of AI and ML in this field is the futuristic approach intended to follow, opening a wide scope of possibilities for improvement in wastewater treatment methodologies.

Developing a PGNAA setup for heavy metal detection in solid samples

Developing a PGNAA setup for heavy metal detection in solid samples

Microbiological and Toxicological Investigations on Bivalve Molluscs Farmed in Sicily.

Bivalves can concentrate biological and chemical pollutants, causing foodborne outbreaks whose occurrence is increasing, due to climatic and anthropic factors that are difficult to reverse, hence the need for improved surveillance. This study aimed to evaluate the hygienic qualities of bivalves sampled along the production and distribution chain in Sicily and collect useful data for consumer safety. Bacteriological and molecular analyses were performed on 254 samples of bivalves for the detection of enteropathogenic Vibrio, Arcobacter spp., Aeromonas spp., Salmonella spp., and beta-glucuronidase-positive Escherichia coli. A total of 96 out of 254 samples, collected in the production areas, were processed for algal biotoxins and heavy metals detection. Bacterial and algal contaminations were also assessed for 21 samples of water from aquaculture implants. Vibrio spp., Arcobacter spp., Aeromonas hydrophila, Salmonella spp., and Escherichia coli were detected in 106/254, 79/254, 12/254, 16/254, and 95/254 molluscs, respectively. A total of 10/96 bivalves tested positive for algal biotoxins, and metals were under the legal limit. V. alginolyticus, A. butzleri, and E. coli were detected in 5, 3, and 3 water samples, respectively. Alexandrium minutum, Dinophysis acuminata, Lingulodinium polyedra, and Pseudonitzschia spp. were detected in water samples collected with the biotoxin-containing molluscs. Traces of yessotoxins were detected in molluscs from water samples containing the corresponding producing algae. Despite the strict regulation by the European Commission over shellfish supply chain monitoring, our analyses highlighted the need for efficiency improvement.

Cost-effective layered double hydroxides/conductive polymer nanocomposites for electrochemical detection of wastewater pollutants

There is an urgent need to develop multifunctional cost-effective nanomaterials and nanocomposites that can be used in numerous applications while showing high efficiency and cheaper implementation compared to conventional techniques and/or materials. In this work, zinc/iron layered double hydroxide (LDH) and polyaniline (PANI) were synthesized as a model LDH/conductive polymer nanocomposite, which is a promising family of cheap multifunctional materials. This electrochemical properties of this nanocomposite was investigated for detection of heavy metal (HM) ions in water streams, using lead as a model HM. In the present work, zinc/iron LDH and PANI was assigned as carbon paste electrode modifier. The composite was fully characterized using various characterization techniques including X-ray diffraction (XRD), scanning electron microscope (SEM), and Fourier transform InfraRed (FTIR). The electrochemical redox reactions of lead (II) ions at the modified electrode interface were investigated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), Accordingly, a linear relation of Pb2+ ions was achieved in the concentration range 1–80 µM with limit of detection (LOD) was 167.8 nM and limit of quantification (LOQ) was 559.4 nM. Furthermore, the cost of using such material for lead removal using a typical adsorption study was compared to using conventional inductively coupled plasma (ICP) or atomic absorption spectrometry (AAS) equipment for tracking HM removal during the adsorption process. Cost analysis revealed that the final overall cost of the modified carbon paste electrode is estimated as 1.25 USD. This cost represents less than 0.1% of the total cost required to conduct the same adsorption study using a typical ICP or AAS equipment. This composite can pave the road towards portable measurements for onsite detection of wastewater pollutants using cheap disposable-electrodes as compared to massive expensive off site equipment such as ICP and AAS.