Determination Of Cadmium Ions Research Articles

An effective procedure used metal–organic framework for determination of cadmium ions in real tap water and human blood plasma samples

A newly developed 2H5MA-MOF sensor by covalently linking NH2-MIL-53(Al) with 2′-Hydroxy-5′-methylacetophenon, designed for highly sensitive and selective detection of Cd2+ ions using fluorometric methods. Detailed structural and morphological analyses confirmed the sensor’s unique properties. It demonstrated an impressive linear detection range from 0 to 2 ppm, with an exceptionally low detection limit of 5.77 × 10−2 ppm and a quantification limit of 1.75 × 10−1 ppm, indicating its high sensitivity (R2 = 0.9996). The sensor also responded quickly, detecting Cd2+ within just 30 s at pH 4. We successfully tested it on real samples of tap water and human blood plasma, achieving recovery rates between 96 % and 104 %. The accuracy of these findings was further validated by comparison with ICP-OES. Overall, the 2H5MA-MOF sensor shows great potential for fast, ultra-sensitive, and reliable detection of Cd2+ ions, making it a promising tool for environmental and biomedical applications.

A new electrochemical sensor based on a screen-printed electrode modified with an ion-imprinted PEDOT for the detection and the quantification of Cd(II)

In this study, an electrochemical sensor was developed using an ion imprinting technique to create a film, facilitating rapid, sensitive, cost-effective and multiplexed determination of cadmium ions in nature. Indeed, pollution by this substance is of great concern due to its toxic health risks and its cumulative and persistent nature in living organisms. The sensor was functionalized with cyclic voltammetry by directly electropolymerizing ethylenedioxythiophene (EDOT) in the presence of Cd(II) as a template on screen-printed platinum electrodes. After electropolymerization, the structure and the morphology of the sensor ion imprinted polyethylendioxythiophene (IIP-PEDOT/SPPtE) were characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and scanning electron microscopy (SEM/EDX). The electrochemical properties of the sensor were studied by cyclic voltammetry and electrochemical impedance spectroscopy. All experimental parameters were optimized by square wave voltammetry. IIP-PEDOT/SPPtE exhibited a linear concentration range of 0.5 to 75 µg/L, a detection limit of 0.07 µg/L and a quantification limit of 0.21 µg/L. Furthermore, the proposed sensor revealed good reproducibility, high stability and high selectivity for cadmium over several potential interferents. The developed device was successfully applied to the Cd(II) detection in industrial water samples via the standard addition method. The results were compared to analyzes of the same samples by ICP-MS. A high recovery rate of around 90–102.2 % and an RSD equal to 5.8 % and 2.5 % were observed.

Cd2+ Detection by an Electrochemical Electrode Based on MWCNT-Orange Peel Activated Carbon.

This study reports the development of a new electrochemical sensor based on a carbon paste electrode (CPE) composed of biomass-based orange peel activated carbon (ACOP) and multiwalled carbon nanotubes (MWCNTs), and this composite is used for the electrochemical detection of cadmium ions (Cd2+). The ACOP/MWCNT composite was characterized by FTIR, Raman, and electrochemical impedance spectroscopy. The electrochemical evaluation of Cd2+ was performed using square wave and cyclic voltammetry. The ACOP/MWCNT-CPE electrochemical sensor exhibited a coefficient of determination r2 of 0.9907, a limit of detection of 0.91 ± 0.79 μmol L-1, and a limit of quantification of 3.00 ± 2.60 μmol L-1. In addition, the developed sensor can selectively detect Cd2+ in the presence of different interferents such as Zn2+, Pb2+, Ni2+, Co2+, Cu2+, and Fe2+ with a relative standard deviation (RSD) close to 100%, carried out in triplicate experiments. The ACOP/MWCNT-CPE presented high sensitivity, stability, and reproducibility and was successfully applied for the detection of Cd2+ in river water samples with recovery rate values ranging from 97.33 to 115.6%, demonstrating to be a very promising analytical alternative for the determination of cadmium ions in this matrix.

Facile synthesis of neodymium vanadate nanoribbons and its application to highly efficient determination of cadmium ions

AbstractBACKGROUNDCadmium ions may be discarded to the environment with living organisms from fossil fuel combustion, phosphate fertilizer and battery industries. It is urgent and essential to develop a sensitive and rapid method for monitoring Cd2+ level in aquatic environments and biological systems. Neodymium vanadate possesses good catalytic performance for the electrocatalysis of heavy metal ions. Single crystalline Nd vanadate nanoribbons were obtained by a facile approach and used as electrode materials for electrochemical detection of Cd2+.RESULTSThe Nd nanoribbons with tetragonal NdVO4 phase possess length, width and thickness of longer than 10 μm, 200 nm to 1.5 μm and 50 nm, respectively. Nd vanadate nanoribbons can serve as a good electron transfer interface. An anodic peak is located at +0.56 V at the Nd vanadate nanoribbon‐modified electrode in 0.1 mol L−1 KCl electrolyte containing 1 mmol L−1 Cd2+ by square wave voltammetry technique. The Nd vanadate nanoribbon‐modified electrode exhibits a linear range of 0.01–1000 μmol L−1 and a detection limit of 0.29 nmol L−1, with good stability, reproducibility and selectivity for Cd2+ detection.CONCLUSIONThe optimal measurement conditions including the pH value of the KCl solution, deposition time, deposition potential and standing time, which are pH 1, 180 s, −1.0 V and 60 s, respectively. The Nd vanadate nanoribbon‐modified electrode shows great application potential for detecting heavy metal ions in liquid environments. © 2023 Society of Chemical Industry.

Electrochemical determination of cadmium ions in biological and environmental samples using a newly developed sensing platform made of nickel tungstate-doped multi-walled carbon nanotubes

Simple and rapid analysis of cadmium ion in environmental and biological samples is of great importance due to the severe toxicity caused by this heavy metal. In the present work, nickel tungstate (NiWO4) dispersion was mixed with multi-walled carbon nanotubes (MWCNTs) to obtain a homogenous composite of (NiWO4/MWCNTs) which 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), Thermo-Gravimetric Analysis (TGA) and Fourier Transform InfraRed (FTIR). The electrochemical redox reactions of cadmium (II) ions at the modified electrode interface were investigated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and linear sweep voltammetry (LSV). Effective parameters on the electro-analysis assay performance including the electrode composition, types of electrolyte, scan rate and pH were tested to achieve the best effective optimum conditions. Accordingly, a linear relation of cadmium ions was achieved in the concentration range 50–450 µM with limit of detection of 0.12 µM. Besides, the proposed electrode was successfully used to monitor trace amounts of cadmium ions in various real samples.Graphical abstractSchematic illustration of synthesis process of NiWO4/MWCN nanocomposite and its application as high-performance cadmium ion sensors

Highly catalytic nanoenzyme of covalent organic framework loaded starch- surface-enhanced Raman scattering/absorption bi-mode peptide as biosensor for ultratrace determination of cadmium.

High affinity peptides (PTs) have been used in nanoanalysis, but there are no reports which combine PTs with a liquid crystal (LC) covalent organic framework (COF) supported soluble starch (SS) catalytic amplification system as a biosensor recognition element. In this study, a new, highly sensitive and selective bi-mode molecular biosensor has been developed for the determination of cadmium ion (Cd2+). Specifically, a highly catalytic and stable COF supported SS nanosol catalyst was fabricated such that a nanocatalytic indicator reaction system for HAuCl4-sodium formate was established based on surface-enhanced Raman scattering (SERS). The Au nanoparticles produced exhibited a surface plasmon resonance (SPR) absorption peak at 535 nm and a SERS peak at 1,615 cm-1. Combining the nanocatalytic amplification indicator system with the specific PTs reaction permitted a sensitive and selective SERS/absorption bi-mode platform to be developed for the determination of cadmium in rice. The linear range for SERS determination was 0.025-0.95 nmol/L and the detection limit (DL) was 0.012 nmol/L.

A highly selective bulk optode based on 6-{4-(2,4-dihydroxy-phenyl)diazenyl)phenyl}-2-oxo-4-phenyl-1,2-dihydro-pyridine-3-carbonitrile incorporating chromoionophore V for determination of nano levels of cadmium

A novel optical sensor has been fabricated for highly accurate, simple and selective determination of nanomolar levels of cadmium ions. The sensor depends on the interaction of 6-{4-(2,4-dihydroxyphenyl)diazenyl)phenyl}-2-oxo-4-phenyl-1,2-dihydropyri-dine-3-carbonitrile (DDPODC) with Cd(II) in plasticized (2-nitrophenyloctyl ether) (o-NPOE) polyvinylchloride (PVC) membrane incorporating chromoionophore V as a lipophilic H+-selective indicator. It would seem that the higher Cd(II) concentration, the lower absorbance of chromoionophore V in the membrane at 668 nm, whereas the absorbance at 586 nm increased. The developed sensor at pH 4.7 has a linear range of 5.0 × 10−12 – 2.5 × 10−5 M with limits of detection and quantification of 1.62 × 10−12 and 4.95 × 10−12 M, respectively. The relative standard deviation (RSD) for eight determination of 1.0 × 10−7 M Cd(II) was 1.67%. Finally, the proposed sensor gives good results for applications in the direct determination of cadmium ions in water, food, and biological samples. Additionally, we compared the obtained results with the data obtained from the flame atomic absorption spectrometry (FAAS).

An Ultrasensitive and Selective Determination of Cadmium Ions at ppt Level Using an Enzymic Membrane with Colorimetric and Electrochemical Detection.

Cadmium ions (Cd2+) are extremely toxic heavy metal pollutants found in the environment, and which endanger human health. Therefore, it is critical to develop a sensitive and simple method for rapidly detecting Cd2+ in water samples. Herein, an enzymic membrane was developed based on an easy and rapid immobilization method of horseradish peroxidase (HRP), for determination of Cd2+ in drinking water. Hence, for the first time, an enzymic membrane was applied for the detection of Cd2+ without being pretreated. In the first format, the inhibition of horseradish peroxidase was performed using a colorimetric microplate reader. Under optimal conditions, the achieved limit of detection was 20 ppt. In addition, an electrochemical biosensor was developed, by combining the enzymic membrane with screen printed electrodes, which showed a linear calibration range between 0.02–100 ppb (R2 = 0.990) and a detection limit of 50 ppt. The use of this enzymic membrane proved to be advantageous when reversible inhibitors such as the copper ion (Cu2+) were present in water samples, as Cu2+ can interfere with Cd2+ and cause erroneous results. In order to alleviate this problem, a medium exchange procedure was used to eliminate Cu2+, by washing and leaving only cadmium ions as an irreversible inhibitor for identification. The use of this membrane proved to be a simple and rapid method of immobilizing HRP with a covalent bond.

Mesoporous silica decorated with L-cysteine as active hybrid materials for electrochemical sensing of heavy metals

Detection of heavy metals using portable electrochemical devices will only become practical if advanced materials with selective interaction to metal ions are found. Mesoporous silica materials are already important performers in nanoscience and nanotechnology scene but they are not considered as active materials for electrochemistry applications. Here, electrochemical sensing of heavy metals is performed using chemically decorated mesoporous silica with L-cysteine (L-cys). Modified electrodes with L-cys/porous silica and square wave voltammetry (SWV) technique were applied for the simultaneous determination of cadmium ion (Cd2+) and lead ion (Pb2+). Two well-known mesoporous silica with honeycomb channel-like pores were used, SBA-15 and MCM-41. Parameters as surface area, pore volume, and average pore size are correlated with the efficiency of electrochemical sensors. Cd2+ and Pb2+ sensors exhibit outstanding results with considerable low detection limit from SBA-15/L-cys (0.22 µg L−1 for Cd2+ and 0.36 µg L−1 for Pb2+) and MCM-41/L-cys (0.23 µg L−1 for Cd2+ and 0.76 µg L−1 for Pb2+). Pore size appears to be the most relevant feature for heavy metal detection and the SBA-15/L-cys, which has large pores, performed better than MCM-41/L-cys regarding detection limit.

A rapid cadmium determination based on ion selective membrane potentiometric sensor by bis (salicylaldehydo)ethylenediimine as carrier

An ion selective potentiometric electrode (IPE) was prepared based on salen material (bis(salicylaldehydo)ethylenediimine) as a suitable carrier for determination of cadmium ions. An acceptable response for cadmium ions obtained over a linear range 8 × 10−7 to 1.0 × 10−2 M with a slope of 29.8 ± 0.8 mV per decade of activity and a detection limit of 3.2 × 10−7 M for Cd (II) ions in water and liquid samples. It has a response time less than 10 s and can be used for at least 2.5 months without any measurable divergence in potential. The ion selective electrode can be used based on potential and potential changes in the pH range 3.5 to 6.5, so, the cadmium determination was obtained at independent pH. Moreover, the selectivity of proposed method in presence of interference ions was studied. The results showed that the other cations do not interfere significantly in response electrode at optimized pH. This electrode was successfully used for the determination of cadmium ions in aqueous samples. The validation was obtained based on ICP analyzer and certified reference material in water samples (CRM, NIST).

A Facile Aptasensor for Instantaneous Determination of Cadmium Ions Based on Fluorescence Amplification Effect of MOPS on FAM-Labeled Aptamer.

Analytical performance and efficiency are two pivotal issues for developing an on-site and real-time aptasensor for cadmium (Cd2+) determination. However, suffering from redundant preparations, fabrications, and incubation, most of them fail to well satisfy the requirements. In this work, we found that fluorescence intensity of 6-carboxyfluorescein(FAM)-labeled aptamer (FAM-aptamer) could be remarkably amplified by 3-(N-morpholino)propane sulfonic acid (MOPS), then fell proportionally as Cd2+ concentration introduced. Importantly, the fluorescence variation occurred immediately after addition of Cd2+, and would keep stable for at least 60 min. Based on the discovery, a facile and ultra-efficient aptasensor for Cd2+ determination was successfully developed. The sensing mechanism was confirmed by fluorescence pattern, circular dichroism (CD) and intermolecular interaction related to pKa. Under the optimal conditions, Cd2+ could be determined rapidly from 5 to 4000 ng mL−1. The detection limit (1.92 ng mL−1) was also lower than the concentration limit for drinking water set by WHO and EPA (3 and 5 ng mL−1, respectively). More than a widely used buffer, MOPS was firstly revealed to have fluorescence amplification effect on FAM-aptamer upon a given context. Despite being sensitive to pH, this simple, high-performance and ultra-efficient aptasensor would be practical for on-site and real-time monitoring of Cd2+.

Rapid detection of cadmium ions in meat by a multi-walled carbon nanotubes enhanced metal-organic framework modified electrochemical sensor

This work presents an electrochemical device based on a composite modification of amine functionalized Zr(IV) metal–organic framework (UiO-66-NH2) and multi-walled carbon nanotubes (MWCNTs) for voltammetry determination of cadmium ions (Cd2+). The UiO-66-NH2@MWCNTs composites were prepared by one-pot hydrothermal reaction. The prepared sensor performs excellent performance, which was attributed to the synergism between UiO-66-NH2 with a special octahedral structure and enlarged surface area and MWCNTs with outstanding conductivity. Under optimal experiment condition, the fabricated sensor showed good linear relationship from 0.5 to 170 μg/L, with a detection limit of 0.2 μg/L. Finally, the sensor was successfully applied to detect Cd2+ in meat samples (N = 21) with relative standard deviation (RSD) lower than 4.5% and recovery of 95.1–107.5%, and the results were compared with certified method, there was no statistical significance difference between the developed sensor and certified method at a 95% confidence level.

Development of immunoassay methods based on monoclonal antibody and its application in the determination of cadmium ion

Owing to the threat of cadmium (Cd2+) to public health, it is an urgent demand to develop effective, sensitive, and rapid methods for the detection of cadmium. In this study, indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) and immunochromatographic test strips (ICTS) were established for the determination of Cd2+ based on the obtained mAb with high specificity and high affinity (Kaff = 3.0 × 109 L/moL). The linear range of ic-ELISA detection was 0.03–1.11 ng/mL and 50% inhibitive concentration (IC50) of cadmium ion was determined to be 0.15 ng/mL. The visual limit of detection (vLOD) of the AuNS-based strip was 0.375 ng/mL. The vLOD of AuNF-based strip using higher intensity reporter determined to be 0.03 ng/mL, which was enhanced 12 times compared to the traditional strip. In summary, the developed immunoassays based on mAb shows great potential for monitoring the cadmium ion in environmental samples.

Determination of Cadmium Ions Based on Electrochemical DNA Biosensors in Rat Tissues

Determination of Cadmium Ions Based on Electrochemical DNA Biosensors in Rat Tissues

Ultrasensitive Trace Determination of Cadmium Through a Green Synthesized Hybrid PVA-Chitosan Nanocomposite

This work describes an ultrasensitive trace determination of cadmium ion in aqueous medium through hybrid nanocomposite. Biodegradable materials such as chitosan and PVA are used to functionalize gold nanoparticles and to form a hybrid nanocomposite. Optical fiber is used to make sensor probe. To reduce toxicity of the gold nanoparticles towards environment, we adopt a green way to synthesize gold nanoparticles. In the optical set up, we have used white LED as light source and optical detector to record output response. From experimental results, we have found that this sensor probe has selectivity towards cadmium. It is found that sensitivity of this probe is ~ 0.028 intensity/ppb. From the linear fit, regression value is found to be ~ 0.99. This sensor probe has offered a limit of detection 800 ppt, which is below the WHO and EPA permissible limit 5 ppb.

New spectrophotometric protocol using tetra-thiosemicarbazone derivative chelating (TTSC) for the assessment of trace level of cadmium(II) in drinking water

ABSTRACTThe chromogenic sulphur containing reagent, tetra-thiosemicarbazone derivative (TTSC), has been sono-synthesised with high yield and characterised to develop a new reagent for the determination of cadmium ion (Cd(II)) in drinking water. The prepared reagent was successfully applied to determine the selective spectrophotometric of Cd(II) in drinking water. In this protocol, Cd(II) reacts selectively with TTSC in a buffer solution of pH 9 to generate an instantly green-coloured complex (Cd+2-TTSC) which has a maximum absorbance at wavelength 422 nm. For more than 24 hours, the Cd+2-TTSC complex remains stable and found to be composed of 2:1 [Cd+2: TTSC]. Variable parameters those affecting the Cd+2-TTSC efficiency were assessed and optimised. Under the optimum conditions, the Cd(II) complex adheres to Beer’s law up to 12 μg/L Cd(II). The analytical validation parameters of the methods in terms of limit of detection (LOD), limit of quantification (LOQ), precision, linearity (r2) and relative standard deviation (RSD%) were assessed and obtained 0.16 μg/L and 0.48 μg/L for LOD and LOQ, respectively, with the linearity of r2 > 0.9995 and RSD% was found to be <2%. The developed method was successfully applied in the simultaneous assessment of Cd(II) in pure forms and spiked samples of water. The reliability and accuracy of the current protocol recommended to be applied for the determination of Cd(II) in all desalination plant and bottled water samples without utilisation of long procedures and sophisticated instrumentation.

Water Soluble Porphyrin for the Fluorescent Determination of Cadmium Ions.

Porphyrins are highly conjugated molecules that perform wide variety of functions in biological systems. They absorb strongly in the visible region and they are excellent fluorophores that emit in the visible region. If the meso or β positions of porphyrins are properly substituted, emission in the NIR region is facilitated. The fluorescence property of porphyrins can be used in sensing applications. Here, we report the synthesis of a water soluble porphyrin that emits in the NIR region and this molecule is used in the fluorescent determination of cadmium ion, which is an environmental pollutant and affects the health of living organisms adversely. 5,10,15,20-tetrakis(4-hydroxy-3,5-dimethoxyphenyl)porphyrin (THMPP), which is water soluble was synthesised from 5,10,15,20-tetrakis(3,4,5-trimethoxyphenyl)porphyrin (TMPP) by partial demethylation, which in turn was synthesized by mixture acid method. The donor-acceptor interaction of THMPP-Cd2+ system displays a dynamic fluorescence quenching through the electron transfer (ET) mechanism. Developed method showed a linear response toward Cd2+ in the concentration range of 0.25μM to 2μM. The limit of detection was found to be 0.1499μM. THMPP exhibited excellent selectivity towards Cd (II) in presence of other metal ions like Hg2+, Mn2+, Mg2+, Co2+ in 1:100, Zn2+, Cu2+, Ni2+ in 1:10 and Na+, K+ in 1:1M ratio.

Preparation of "Ion-Imprinting" Difunctional Magnetic Fluorescent Nanohybrid and Its Application to Detect Cadmium Ions.

In this work, we have fabricated a novel difunctional magnetic fluorescent nanohybrid (DMFN) for the determination of cadmium ions (Cd2+) in water samples, where the “off-on” model and “ion-imprinting” technique were incorporated simultaneously. The DMFN were composed of CdTe/CdS core-shell quantum dots (QD) covalently linked onto the surface of polystyrene magnetic microspheres (PMM) and characterized using ultraviolet-visible spectroscopy (UV-Vis), fluorescence spectroscopy, and transmission electron microscopy (TEM). Based on the favorable magnetic and fluorescent properties of the DMFN, the chemical etching of ethylene diamine tetraacetic acid (EDTA) at the surface produced specific Cd2+ recognition sites and quenched the red fluorescence of outer CdTe/CdS QD. Under optimal determination conditions, such as EDTA concentration, pH, and interfering ions, the working curve of determining Cd2+ was obtained; the equation was obtained Y = 34,759X + 254,894 (R = 0.9863) with a line range 0.05–8 μM, and the detection limit was 0.01 μM. Results showed that synthesized magnetic fluorescent microspheres had high sensitivity, selectivity, and reusability in detection. Moreover, they have significant potential value in fields such as biomedicine, analytical chemistry, ion detection, and fluorescence labeling.

Thiolated poly(aspartic acid)-functionalized two-dimensional MoS2, chitosan and bismuth film as a sensor platform for cadmium ion detection.

In this work, a sensitive electrochemical platform for determination of cadmium ions (Cd2+) is obtained using thiolated poly(aspartic acid) (TPA)-functionalized MoS2 as a sensor platform by differential pulse anodic stripping voltammetry (DPASV). The performance of the TPA–MoS2-modified sensor is systemically studied. It demonstrates that the TPA–MoS2 nanocomposite modified sensor exhibits superior analytical performance for Cd2+ over a linear range from 0.5 μg L−1 to 50 μg L−1, with a detection limit of 0.17 μg L−1. Chitosan is able to form a continuous coating film on the surface of the GC electrode. The good sensing performance of the TPA–MoS2-modified sensor may be attributed to the following factors: the large surface area of MoS2 (603 m2 g−1), and the abundant thiol groups of TPA. Thus, the TPA–MoS2-modified sensor proves to be a reliable and environmentally friendly tool for the effective monitoring of Cd2+ existing in aquacultural environments.

Application of surface-active ionic liquids in micelle-mediated extraction methods: pre-concentration of cadmium ions by surface-active ionic liquid-assisted cloud point extraction

In this work, a modified cloud point extraction method based on the micellar features of a surface-active ionic liquid (SAIL) was developed. Mixture of a nonionic surfactant (Triton X-114) and a surface-active ionic liquid, 1-hexadecyl-3-methylimidazolium chloride (C16MeImCl), was used as an extracting phase for pre-concentration of cadmium ions prior to the determination by flame atomic absorption spectrometry. According to the obtained results, by using this route, the extraction efficiency of the investigated analyte was improved. On the other hand, more reproducible measurements were established. These features could be attributed to the enhancement effect of the SAIL on the extraction efficiency and its influence on the completeness and ease of separation of the extracting phase from the aqueous phase at the last step of the extraction process. Comparison of the obtained results against those acquired by using the same procedure in the absence of SAIL showed the advantages of the proposed method. Under the optimal conditions, the calibration curve of Cd2+ was linear in the range of 1–500 μg L−1 with correlation coefficient of 0.9999 and a detection limit of 0.6 μg L−1. The relative standard deviation for eight replicate measurements of 100 μg L−1 Cd2+ was 0.8%. To show the validity and application of the suggested procedure, it was applied successfully for the determination of cadmium ions in various real water samples.