Detection Of Heavy Metals Research Articles

Fabrication of Paper-Based Silver Nanoparticle (AgNP) Sensors for Smartphone-Based Colorimetric Detection of Cu (II) in Water

Detection of heavy metals in water has long been a key area of study due to the adverse health effects these substances may bring. Multiple methods of detecting heavy metals have already been established. Though these methods are highly selective and can detect heavy metals in trace amounts, they commonly require specialized equipment. Thus, producing an inexpensive, reliable, and convenient sensor that could be used for point-of-need applications is of great interest. This study focuses on fabricating paper-based silver nanoparticle (AgNP) sensors for the smartphone-based colorimetric detection of Cu2+ ions in water. Polymer-decorated AgNPs functionalized by chitosan, glutaraldehyde, and polyethyleneimine were used as the main sensing mechanism for the paper-based sensors. Various fabrication methods were tested, and the optimal fabrication method was through the rectangular soak method with a total of 5 coatings as it produced the most uniform sensors. The calibration curve was studied over concentrations from 0.5 mM to 50 mM of Cu2+ across multiple parameters. It was found that there was a linear correlation between the Euclidean distance measured in reference to the blank filter paper against the concentration of copper in the analyte. The calibration curve exhibited a dynamic linear range between 2 mM to 28 mM of Cu2+ with R2 = 0.99789. The LOD and LOQ were reported at 94.9438 ppm and 316.4793 ppm, respectively. Lastly, selectivity studies were also performed to determine the sensor’s response to other metal ions. It was found that the response of the sensor to Cu2+ was significantly different from those elicited by Ni2+, Cd+, Mn2+, Ca2+, Mg2+, Sn2+, K+, Cr3+, Al3+, Ba2+, Na+, Zn2+, Fe3+, and Fe2+. The study demonstrated its strong potential as rapid on-site detection method for Cu (II) in industrial wastewater.

Characterization of heavy metal-associated bacteria from petroleum-contaminated soil and their resistogram and antibiogram analysis.

The aim of the current study was to screen and identify heavy metal (chromium, cadmium, and lead) associated bacteria from petroleum-contaminated soil of district Muzaffarabad, Azad Jammu and Kashmir, Pakistan to develop ecofriendly technology for contaminated soil remediation. The petroleum-contaminated soil was collected from 99 different localities of district Muzaffarabad and the detection of heavy metals via an atomic absorption spectrometer. The isolation and identification of heavy metals-associated bacteria were done via traditional and molecular methods. Resistogram and antibiogram analysis were also performed using agar well diffusion and agar disc diffusion methods. The isolated bacteria were classified into species, i.e., B. paramycoides, B. albus, B. thuringiensis, B. velezensis, B. anthracis, B. pacificus Burkholderia arboris, Burkholderia reimsis, Burkholderia aenigmatica, and Streptococcus agalactiae. All heavy metals-associated bacteria showed resistance against both high and low concentrations of chromium while sensitive towards high and low concentrations of lead in the range of 3.0 ± 0.0mm to 13.0 ± 0.0mm and maximum inhibition was recorded when cadmium was used. Results revealed that some bacteria showed sensitivity towards Sulphonamides, Norfloxacin, Erythromycin, and Tobramycin. It was concluded that chromium-resistant bacteria could be used as a favorable source for chromium remediation from contaminated areas and could be used as a potential microbial filter.

Research progress of the detection and analysis methods of heavy metals in plants.

Heavy metal (HM)-induced stress can lead to the enrichment of HMs in plants thereby threatening people's lives and health via the food chain. For this reason, there is an urgent need for some reliable and practical techniques to detect and analyze the absorption, distribution, accumulation, chemical form, and transport of HMs in plants for reducing or regulating HM content. Not only does it help to explore the mechanism of plant HM response, but it also holds significant importance for cultivating plants with low levels of HMs. Even though this field has garnered significant attention recently, only minority researchers have systematically summarized the different methods of analysis. This paper outlines the detection and analysis techniques applied in recent years for determining HM concentration in plants, such as inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectrometry (AAS), atomic fluorescence spectrometry (AFS), X-ray absorption spectroscopy (XAS), X-ray fluorescence spectrometry (XRF), laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), non-invasive micro-test technology (NMT) and omics and molecular biology approaches. They can detect the chemical forms, spatial distribution, uptake and transport of HMs in plants. For this paper, the principles behind these techniques are clarified, their advantages and disadvantages are highlighted, their applications are explored, and guidance for selecting the appropriate methods to study HMs in plants is provided for later research. It is also expected to promote the innovation and development of HM-detection technologies and offer ideas for future research concerning HM accumulation in plants.

Pyrene‐Appended Luminescent Probes for Selective Detection of Toxic Heavy Metals and Live Cell Applications

AbstractHeavy metal contamination has become a global environmental problem and currently drawn much attention from researchers in worldwide. High exposure to heavy metals can lead to problems like kidney, liver and brain damage, skin and lung cancer, etc. Rapid and sensitive detection of heavy metals is of immense importance in environmental monitoring. Over the past few decades, enormous efforts have been made to design various sensors to identify and monitor these harmful metal ions. In Comparison with other methods, fluorescence‐based chemosensors have received extensive attention because of the advantages of high sensitivity, low cost, real‐time monitoring, simple operation, etc. The pyrene derivatives are significant polycyclic aromatic hydrocarbons (PAHs) with strong fluorescence. They are widely used as fluorescent probes in many applications due to their easy modification, high fluorescence quantum yield, and strong fluorescence emission in live cells, outstanding cell permeability, and very low cytotoxicity. The SDG 6: Clean water and sanitation alarm a strong strategy, and careful identification of the risk connected to environmental pollutants needs urgent attention in this situation. Therefore, we highlight different types of pyrene‐based fluorophores and the fluorescence mechanisms for the sensitive and selective detection methodology of Arsenic, Mercury, Cadmium, Lead, and Chromium heavy metals.

Determination of copper and cobalt in different tea samples at trace levels by FAAS after preconcentration with a novel iron PAMAM-OH-encapsulated magnetic nanoparticle as SPE sorbent.

Environmental contamination caused by heavy metals is a significant global concern. The presented study investigated the efficiency of iron PAMAM-OH encapsulated magnetic nanoparticles (Fe-MNP-G2-OH) as sorbent for the preconcentration of copper and cobalt from tea samples. High metal-chelating ethylenediamine core polyamidoethanol generation-2 (PAMAM-G2-OH) was encapsulated with iron oxide (Fe3O4) to synthesize the sorbent. Limit of detection (LOD) values for copper and cobalt extracted and detected by the developed Fe-MNP-G2-OH -SPE-FAAS method were 0.52 and 1.1μg L-1, respectively. There were 230- and 101-fold improvement in detection limits for copper and cobalt, respectively, when compared to direct FAAS measurement. The percent recovery results for the analytes in green and black tea samples ranged from 93 to 107%, with low relative standard deviation (%RSD) values. The synthesis of nanoparticle was carried out through a unique method, which was characterized by thermogravimetric analysis (TGA), scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) methods. The analytical results demonstrated the applicability and effectiveness of Fe-MNP-G2-OH nanoparticles on the preconcentration of copper and cobalt from tea samples and the developed method is suitable for the trace detection of heavy metals by FAAS method. To the best our knowledge, this is the first study where copper and cobalt in green and black tea samples were extracted by Fe-MNP-G2-OH adsorbent and precipitation of the adsorbent during its synthesis was carried out in acetone medium rather than aqueous one.

Detection of Aflatoxin M1 and Several Heavy Metals in Medical Infant Milk Formula Sold in Iraqi Markets

Milk is essential for infants, and infant feeding should be emphasized in any program to ensure good child health. To find harmful and trace elements in different milk powder brands bought in Iraq and fed to babies with metabolic syndrome, atomic absorption spectrometry (AAS) was used. Fluorescence high-performance liquid chromatography (HPLC) was also used to measure aflatoxin M1. The result reveals the concentrations of elements close to the product label's description, such as magnesium, calcium, zinc, selenium, iron, and manganese. Only the potassium element was higher than what was listed on the product label. Additionally, no quantities of hazardous elements like lead (Pb), cadmium (Cd), or arsenic (As) were found. As for aflatoxin M1, it was found that the PKU milk formula and lactose-free milk formula were found to be free of AFM1 contamination, indicating that they are safe to consume. AFM1 was found in concentrations above the permissible limit in the MSUD milk formula (0.08 µg/kg). The reason for this issue could be inadequate storage. The other two types, TYR and OAc milk formula, were lower than the allowable limit of 0.05 µg/kg. As a result, there needs to be more oversight of the milk that newborns with metabolic syndrome consumele S. aureus or Streptococcus pyogenes, and Streptococcus pneumoniae in community settings.

Sensing of heavy metal Pb2+ ions in water utilizing the photonic structure of highly controlled hexagonal TiON/TiO2 nanotubes

The detection of heavy metals in water, especially Pb2+ ions, is important due to their severe hazardous effects. To address this issue, a highly controlled hexagonal TiON/TiO2 heterostructure has been synthesized in this study. The fabrication process involved the utilization of atomic layer deposition and direct current sputtering techniques to deposit TiO2 and TiON layers onto a porous Al2O3 membrane used as a template. The resulting heterostructure exhibits a well-ordered hollow tube structure with a diameter of 345 nm and a length of 1.2 µm. The electrochemical sensing of Pb2+ ions in water is carried out using a cyclic voltammetry technique under both light and dark conditions. The concentration range for the Pb2+ ions ranges from 10–5 to 10–1 M. The sensitivity values obtained for the sensor are 1.0 × 10–6 in dark conditions and 1.0 × 10–4 in light conditions. The remarkable enhancement in sensitivity under light illumination can be attributed to the increased activity and electron transfer facilitated by the presence of light. The sensor demonstrates excellent reproducibility, highlighting its reliability and consistency. These findings suggest that the proposed sensor holds great promise for the detection of Pb2+ ions in water, thereby facilitating environmental monitoring, water quality assessment, and safety regulation across various industries. Furthermore, the eco-friendly and straightforward preparation techniques employed in its fabrication provide a significant advantage for practical and scalable implementation.

Photometric Determination of Cobalt (Ii) With 4-Sulfo β-Nitroso α-Naphthol

At the moment development of science and technology sets important tasks for the science of analytical chemistry. Toxic compounds from various biological and industrial facilities and the development of methods for the separation and detection of their decomposition products one of the main tasks of analytical chemistry.
 Photometric detection, one of the most modern physical and chemical methods for the detection of heavy metals, is widely used today and the new organic reagents are being used to address these issues.
 Photometric determination of micro quantities of elements using organic reagents is one of the new developing methods. Photometric method is fast in nature and does not require expensive equipment with fast and cheap selective action.

Studies on adsorption properties of magnetic composite prepared by one-pot method for Cd(II), Pb(II), Hg(II), and As(III): Mechanism and practical application in food

A one-pot synthesis afforded a magnetic, crosslinked polymer adsorbent (m-P6) with a variety of functional groups to realize simultaneous adsorption of Cd2+, Pb2+, Hg2+, and As3+. The material was characterized by TEM-EDS, XRD, FT-IR, VSM, and XPS. Kinetic and isothermal analyses suggested mainly chemisorption processes of heavy metal ions that form multiple layers on heterogeneous surfaces. Theoretical adsorption capacities calculated by a pseudo-2nd-order kinetic model and the Sips isothermal model were 282.88 mg/g for Cd2+, 326.18 mg/g for Pb2+, 117.85 mg/g for Hg2+, and 320.29 mg/g for As3+. m-P6 not only can efficiently adsorb divalent heavy metals (Cd2+, Pb2+, Hg2+), but also demonstrate a process of adsorption-driven catalytic oxidation by single-electron transfer (SET) from As3+ to As5+. In application, in addition to adsorption in water, m-P6 is capable of minimizing matrix interference, and extracting trace heavy metals in a complex environment (cereal) through easy operations for improving the detection accuracy, as well as it is potential for application in detection of trace heavy metals in foodstuffs. m-P6 can be readily regenerated and efficiently recycled for 5 cycles using eluent E12 and dilute acid.

Phenyl-modified carbon nitride based multifunctional gel for the detection, adsorption, photocatalytic reduction and recycling of chromium(VI) in wastewater

It is of vital significance to explore effective and economical multifunctional materials for the detection, remediation and recycling of heavy metal (Cr(VI)). Herein, two-dimensional (2D) phenyl-modified carbon nitride (PCN) polymer was prepared through thermal polymerization of phenylguanidine carbonate. The incorporation of phenyl groups endowed PCN polymer with both strong green fluorescence and high photocatalytic activity for the reduction of Cr(VI). An multifunctional gel for simultaneous detection, adsorption, photo-reduction and recycling of Cr(VI) was further prepared by assembling PCN with polyethyleneimine–N,N’-methylenebisacrylamide (PEI-MBA) gel. PCN-PEI-MBA gel showed a sensitive fluorescence / colorimetric dual-mode detection of Cr(VI). Meanwhile, PCN-PEI-MBA gel displayed preeminent adsorption capacity of 3055.9 mg g−1, surpassing previously reported adsorbents. Under visible-light irradiation, the absorbed Cr(VI) in PCN-PEI-MBA gel was photocatalytically reduced into Cr(III) with visual real-time monitoring the detoxification process and Cr(III) can be further recycled as Cr2O3 by calcination of PCN-PEI-MBA gel. Finally, PCN-PEI-MBA gel was utilize to adsorb and recycle Cr(VI) from the chromium-plating wastewater and detect the concentration of remaining Cr(VI) in the wastewater. This work provides an all-in-one treatment strategy for the detection, remediation and resource recycling of Cr(VI) in practical wastewater.

Detection, distribution, and health risk assessment of heavy metals in wild catfish sold in Maiduguri Metropolis of Borno State, Northeastern Nigeria

Heavy metals (HMs) are naturally occurring elements with high atomic weights and a density at least five times greater than water. HMs can be released into the soil, water, and air through industrial, domestic, agricultural run-offs, medical and technological activities. Thirty wild fresh catfish were bought from two major fish markets in Maiduguri (Custom and Monday markets). Zinc (Zn) and Arsenic (As) were determined by Atomic Absorption spectrophotometer. Data obtained were analyzed using descriptivestatistics and independent sample t-tests. The estimated daily intake (EDI) of the metals was calculated, and the target cancer risk (TCR), target hazard quotient (THQ), and hazard index (HI) was derived. The mean concentration (mg/Kg ± SD) of Zn in the liver (0.26 ± 0.32) was higher compared to that in muscle (0.22 ± 0.27), but this was not statistically different (t (58) = 0.608, p = 0.545). However, the mean concentration of As in the liver (0.27 ± 0.33) was lower compared to that in the muscle (0.28 ± 0.23), but this was not statistically different (t (52) = -0.003, p = 0.997). Although, no significant statistical difference, the mean concentration ranking of Zn based on the Fish market was Monday market > custom market, while that of As was custom market > Monday market. EDI values were within tolerable limits. TCR, THQ, and HI values obtained were below the threshold of 1. In conclusion, HMs (Zn and As) were detected in the liver and muscle of all fish samples tested at a lower rate compared to their Maximum Permissible Limits (MPLs) set by the World Health Organization (WHO). However, because of their non-degradable nature and tendency to bio-accumulate in fish tissues and organs, it can be concluded that long-term consumption poses a greater Public Health risk of HMs intoxications in the study area. Therefore, fish consumers should be enlightened more about the harmful effects of HM toxicity by relevant health authorities.

Two-mode sensing strategies based on tunable cobalt metal organic framework active sites to detect Hg2+

Heavy metal pollution poses a major threat to human health, and developing a user-deliverable heavy metal detection strategy remains a major challenge. In this work, two-mode Hg2+ sensing platforms based on the tunable cobalt metal-organic framework (Co-MOF) active site strategy are constructed, including a colorimetric, and an electrochemical assay using a personal glucose meter (PGM) as the terminal device. Specifically, thymine (T), a single, adaptable nucleotide, is chosen to replace typical T-rich DNA aptamers. The catalytic sites of Co-MOF are tuned competitively by the specific binding of T-Hg2+-T, and different signal output platforms are developed based on the different enzyme-like activities of Co-MOF. DFT calculations are utilized to analyze the interaction mechanism between T and Co-MOF with defect structure. Notably, the two-mode sensing platforms exhibit outstanding detection performance, with LOD values as low as 0.5 nM (colorimetric) and 3.69 nM (PGM), respectively, superior to recently reported nanozyme-based Hg2+ sensors. In real samples of tap water and lake water, this approach demonstrates an effective recovery rate and outstanding selectivity. Surprisingly, the method is potentially versatile and, by exchanging out T-Hg2+-T, can also detect Ag+. This simple, portable, and user-friendly Hg2+ detection approach shows plenty of promise for application in the future.

The application progress of magnetic solid-phase extraction for heavy metal analysis in food: a mini review.

The emerging sample pretreatment technique of magnetic solid-phase extraction (MSPE) has drawn the attention of researchers owing to its advantages of less reagent consumption, fast separation/enrichment process, high adsorption capacity, and simple operation. This paper presents a review of synthesis techniques, classification, and analysis procedures for MSPE in the detection of heavy metals in food. Magnetic adsorbents derived from silica, metal oxides, carbon, polymers, etc., are applied for the detection of heavy metals in food. Then, the recent development of the technology of MSPE for the analysis of heavy metal extraction in food is summarized in detail. Finally, the future outlook for the improvement of MSPE is also discussed.

Chemical sensor thin film-based carbon quantum dots (CQDs) for the detection of heavy metal count in various water matrices.

Rising pollution of heavy metals is one of the greatest concerns, especially in water resources globally and has led to significant adverse effects to human health. To uplift the status of human health, detection of heavy metals is of key importance. This study establishes the ability of carbon quantum dot (CQD)-based thin films for the detection of total heavy metal counts based on a fluorescence-based mechanism in various water resources using a fiber optic spectrometer (FOS) device. CQDs and CQD thin films were characterized using various techniques, such as X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray diffraction (XRD), and confocal laser scanning microscopy (CLSM), and the sensing capability was evaluated for the detection of heavy metals using an optical fiber system. The analytical parameters of the CQD-based thin film were compared with the estimation carried out using a micro plasma-atomic emission spectroscopy (MP-AES) method. The sensing performances of CQD thin films indicate that they are able to detect five heavy metals individually (lead, nickel, manganese, cobalt and chromium) in combination with a response time of 1 minute. The CQD thin films were able to detect heavy metals with a detection limit of 0.006-0.019 ppm for the analyzed heavy metals with a linear range of estimation analyzed as 0-100 μM. The accuracy of the estimation of all five heavy metals when spiked in various real water samples lies in the range of 100-103%. The result of the study clearly indicates that CQD thin films associated with a fiber optic device have the potential to play a role in point-of-care devices for total heavy metal count detection in complex matrices of water.

High-sensitivity analysis of trace elements in water using femtosecond LIBS with dry droplet pretreatment on a metallic substrate

Femtosecond LIBS with dry droplet pretreatment for detecting trace elements in water showed a significant decrease in LOD with increasing titration number, indicating that this method can achieve high sensitivity analysis of trace elements in water.

Integrated microfluidic platforms for heavy metal sensing: a comprehensive review.

Heavy metals are found naturally; however, anthropogenic activities such as mining, inappropriate disposal of industrial waste, and the use of pesticides and fertilizers containing heavy metals can cause their unwanted release into the environment. Conventionally, detection of heavy metals is performed using atomic absorption spectrometry, electrochemical methods and inductively coupled plasma-mass spectrometry; however, they involve expensive and sophisticated instruments and multistep sample preparation that require expertise for accurate results. In contrast, microfluidic devices involve rapid, cost-efficient, simple, and reliable approaches for in-laboratory and real-time monitoring of heavy metals. The use of inexpensive and environment friendly materials for fabrication of microfluidic devices has increased the manufacturing efficiency of the devices. Different types of techniques used in heavy metal detection include colorimetry, absorbance-based, and electrochemical detection. This review provides insight into the detection of toxic heavy metals such as mercury (Hg), cadmium (Cd), lead (Pb), and arsenic (As). Importance is given to colorimetry, optical, and electrochemical techniques applied for the detection of heavy metals using microfluidics and their modifications to improve the limit of detection (LOD).

Review on the application of upconversion nanomaterials in heavy metal detection

Review on the application of upconversion nanomaterials in heavy metal detection

Hydrothermal synthesis of B, S, and N-doped carbon quantum dots for colorimetric sensing of heavy metal ions.

In this study, glucose was used as the carbon source to synthesize carbon quantum dots (CQDs) and also aimed to synthesize CQDs doped with heteroatoms such as sulphur, nitrogen, and boron to enhance their functionality. The obtained material has been characterized by several techniques. According to FL analysis, the highest peaks for CQD, N-CQD, B-CQD, and S-CQD were determined as 432 nm (ex 350), 425 (ex 350), 430 nm (ex 340 nm), and 436 nm (ex 340 nm), respectively. FTIR spectra showed different characteristic peaks for CQD, and the FTIR results show that CQDs have a unique structure. According to TEM analysis, the morphology of all CQDs was found to be spherical and monodisperse with average sizes in the range of 5-7 nm. The characterization results of CQDs show that the addition of heteroatoms changes the properties of CQDs. The synthesized CQDs were also tested as colorimetric sensors for the detection of heavy metals. It was observed that CQDs detected Fe3+ metal ions, B-CQD and S-CQD detected Fe3+ and Ag+ metal ions, and N-CQDs detected Ca2+ metal ions. Sensor studies were performed for all CQDs and linear plots were obtained against metal concentrations in the range of 0.06-1.23 μM. LOD values for CQD, N-CQD, S-CQD, and B-CQD were calculated as 0.187 μM (Fe3+), 0.391 μM (Ca2+), 0.224 μM (Fe3+)-0.442 μM (Ag+), and 0.182 μM (Fe3+)-0.174 μM (Ag+), respectively. The results show that the addition of B, N, and S atoms to CQDs plays a role in the improvement and modification of colorimetric sensor properties and has the potential to be used in sensor applications for the detection of heavy metals in areas such as the environment and health.

Development of a flow system for decentralized electrochemical analysis of heavy metals using screen-printed electrodes: the importance of sensor stability.

Year after year, the need for decentralized tools to tackle the monitoring of heavy metal levels in the environment gradually increases. In this context, suitable electrochemical methodologies are widely established and particularly attractive for the production of low-cost miniaturized field-deployable analytical platforms. This work focused on the development of an automatable portable system based on square-wave anodic stripping voltammetry (SWASV) for the on-line detection of heavy metals. The surface of the sensors is appropriately modified and coupled with a fluidic system equipped with an ad-hoc designed flow cell. A custom software tool was introduced to handle the remote-controlled potentiostat and automate the various steps of the procedure, including stirring operations, cleaning phases, SWASV measurements, and data collection. After studying technical and analytical challenges, the final system developed was applied to the simultaneous detection of Cd(II), Pb(II), and Cu(II) in solution, achieving sub-ppb detection limits. Additionally, the practical applicability of the method was successfully applied to river water samples collected from the Loire basin in France.

Investigating the effects of laser wavelengths and other ablation parameters on the detection of biogenic elements and contaminants in hydroxyapatite

A comparison of laser ablation measurement parameters (laser wavelength, energy, gate delay, defocus, and spot size) to determine optimal settings for the detection of heavy metals and biogenic elements in a hard tissue matrix (hydroxyapatite).