Electrochemical Detection Of Pb Research Articles

Electrochemical Detection of Heavy Metal Ions using Gold Nanoparticles on Carbon Dots Extracted from Curry Leaves

Carbon dots (CDs) have attracted attention due to their versatility in electronic and optical properties based on precursor and type of synthesis process. Recently, many researchers have focused on using natural resources or wastes to form CDs. Four samples of CDs have been synthesized from curry leaves using a microwave-assisted approach at heating powers of 700 and 800 V with durations of 5 and 8 minutes. UV-Vis and FTIR spectra reveal the existence of carbon graphitic elements with carboxyl and hydroxyl functional groups on the surfaces of CDs. CVs of AuNPs/CDs/GS electrodes in ferricyanide disclosed that as-synthesized CDs produced using a lower heating power of 700 W exhibit pronounced electrocatalytic activity with sluggish electron transfer kinetics. Conversely, as-synthesized CDs created with a higher heating power of 800 W demonstrate reduced electrocatalytic activity but rapid electron transfer kinetics. Electrochemical detection of Pb2+ ions was observed through a sharp peak around -0.42 to -0.438 V, while detection of Hg2+ ions was observed through two anodic peaks around +0.334 to +0.408 V during a forward scan in acetate buffer (pH 4.5) on AuNPs/CDs/GS electrodes when tested individually. These distinct peaks also appeared in mixture solutions, with a slight reduction in peak current density that suggests the selectivity of the AuNPs/CDs/GS electrodes towards Pb2+ and Hg2+ ion detection. The optimum AuNPs/CDs/GS electrode for sensitive and selective detection of Pb2+ and Hg2+ was recorded using CDs D as a functional supporting matrix for AuNPs that was synthesized using a heating power of 800 W for 8 minutes.

A unique covalently linked pyridine-tetrathiafulvalene as a stimuli-sensitive sensor for the specific, selective optical and electrochemical detection of Pb2+

A Py-TTF dyad designed for specific detection and release of Pb2+ ions.

Electrolytic Growth of Sulfhydryl-Functionalized Silica Nanochannel Membrane for Anti-Fouling Electrochemical Detection of Pb2+ in Soil

Electrolytic Growth of Sulfhydryl-Functionalized Silica Nanochannel Membrane for Anti-Fouling Electrochemical Detection of Pb2+ in Soil

Sulfhydryl-Functionalized Silica Nanochannel Membrane for Anti-Fouling Electrochemical Detection of Pb2+ in Soil

Sulfhydryl-Functionalized Silica Nanochannel Membrane for Anti-Fouling Electrochemical Detection of Pb2+ in Soil

Electrochemical Characterization and Detection of Lead in Water Using SPCE Modified with BiONPs/PANI.

The need for constant assessment of river water qualities for both aquatic and other biological survival has emerged a top priority, due to increasing exposure to industrial pollutants. A disposable screen print carbon electrode was modified with a conductive polymer (PANI) and Zn and/or Cu oxides NPs, obtained through bioreduction in citrus peel extracts (lemon and orange), for ultra-sensitive detection of PB2+, in the Crocodile River water sample. The synthesized materials were characterized with Fourier-transform infra-red spectroscopy (FTIR), ultra-violet visible spectroscopy (UV-Vis), and scanning electron microscopy (SEM). The SPC-modified electrodes designated as SPCE/LPE/BiONPs/PANI and SPCE/OPE/BiONPs/PANI were characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) and eventually deployed in the electrochemical detection of PB2+ in water using square wave voltammetry (SWV) technique. The electrochemical responses of the modified electrodes for both CV and EIS in 0.1 M HCl demonstrated enhanced performance relative to the bare SPCE. A detection and quantification limit of 0.494 ppb and 1.647 were obtained at SPCE/LPE/BiONPs/PANI, respectively, while a detection and quantification limit of 2.79 ppb and 8.91 ppb, respectively, were derived from SPCE/OPE/BiONPs/PANI. The relative standard deviations (RSD) for SPC electrode at a 6.04 µM PB2+ analyte concentration was 4.76% and 0.98% at SPCE/LPE/BiONPs/PANI and SPCE/LPE/BiONPs/PANI, respectively. The effect of copper, zinc, iron, cobalt, nickel, and magnesium on the stripping peaks of PB2+ at SPCE/OPE/BiONPs/PANI, showed no significant change except for cobalt, with about 17.67% peak current drop. The sensors were assessed for possible determination of PB2+ in spiked river water samples. The average percentage recovery and RSD calculated were 94.25% and 3.74% (n = 3) at SPCE/LPE/BiONPs/PANI and, 96.70% and 3.71% (n = 3) at SPCE/OPE/BiONPs/PANI, respectively. Therefore, the fabricated sensor material could be used for environmental assessment of this highly toxic heavy metal in the aquatic system

One-step synthesis of Ag nanoparticles decorated graphene for application in electrochemical detection of Pb2+ and Cd2+ ions

One-step synthesis of Ag nanoparticles decorated graphene for application in electrochemical detection of Pb2+ and Cd2+ ions

Sensitive Electrochemical Detection of Pb(II) and H2O2 via a Dual‐functional Sn‐doped Defective Bi2S3 Microspheres

AbstractIn this work, a dual‐functional electrochemical sensor has been proposed based on Sn‐doped defective Bi2S3 (TDDB) microspheres, which exhibited the excellent electrochemical performance on Pb(II) and H2O2 detection. The TDDB offered a satisfied detection limit of 8.0 nM towards Pb(II) with a sensitivity of 96.7 μA ⋅ μM−1. As a H2O2 sensor, a high sensitivity of 3540 μA mM−1 cm−2 was obtained in a linear range from 0.45 mM to 10 mM with a detection limit of 10 nM. Moreover, the electrochemical detection of Pb(II) in Taihu Lake and H2O2 in human serum was achieved with high reliability and good recovery.

Electrochemical Sensor for Determination of Pb2+ Based on Gold Nanoparticles.

We report the formation of gold nanoparticles on indium tin oxide conducting glass (ITO) surface via electrodeposition method at room temperature. The prepared nano-Au electrodes has been fabricated for sensitive detection of Pb2+, and showed highly selective response toward Pb2+. The electrochemical detection of Pb2+ were determined by differential pulse stripping voltammetric (DPSV). The nano-Au electrochemical sensor could detect Pb2+ from 0.5 to 10 μM with detection limits of 0.06 μM (S/N= 3) and sensitivity of 0.27996 mA μM-1. The proposed sensor is simple, reliable, sensitive, selective, and low-cost, thus holds potential for practical application in Pb2+ detection.

Nanocomposite Platform Based on EDTA Modified Ppy/SWNTs for the Sensing of Pb(II) Ions by Electrochemical Method.

Heavy metal ions are considered as one of the major water pollutants, revealing health hazards as well as threat to the ecosystem. Therefore, investigation of most versatile materials for the sensitive and selective detection of heavy metal ions is need of the hour. Proposed work emphasizes the synthesis of conducting polymer and carbon nanotube nanocomposite modified with chelating ligand for the detection of heavy metal ions. Carbon nanotubes are having well known features such as tuneable conductivity, low density, good charge transport ability, and current carrying capacity. Conducting polymers are the most reliable materials for sensing applications due to their environmental stability and tuning of conductivity by doping and de-doping. Formation of nanocomposite of these two idealistic materials is advantageous over the individual material, which can help to tackle the individual limitations of these materials and can form versatile materials with ideal chemical and electrical properties. Chelating ligands are the most favorable materials due to their ability of complex formation with metal ions. The present work possesses a sensing platform based on conducting polymer and carbon nanotube nanocomposite, which is stable in various aqueous media and possess good charge transfer ability. Chelating ligands played an important role in the increased selectivity toward metal ions. Moreover, in present investigation Ethylenediaminetetraacetic acid (EDTA) functionalized polypyrrole (Ppy) and single walled carbon nanotubes (SWNTs) nanocomposite was successfully synthesized by electrochemical method on stainless steel electrode (SSE). The electrochemical detection of Pb(II) ions using EDTA-Ppy/SWNTs nanocomposite was done from aqueous media. Cyclic voltammetry technique was utilized for the electrochemical synthesis of Ppy/SWNTs nanocomposite. Ppy/SWNTs nanocomposite was further modified with EDTA using dip coating technique at room temperature. The EDTA-Ppy/SWNTs modified stainless steel electrode (SSE) exhibited good sensitivity and selectivity toward heavy metal ions [Pb(II)]. Detection limit achieved for Pb(II) ions was 0.07 μM.

Design of L-cysteine functionalized Au@SiO2@Fe3O4/nitrogen-doped graphene nanocomposite and its application in electrochemical detection of Pb2+

A novel magnetic electrochemical sensor was designed for determination of lead ions based on gold nanoparticles(AuNPs)@SiO2@Fe3O4/nitrogen-doped graphene(NG) composites functionalized with L-cysteine. The Au@SiO2@Fe3O4/NG was synthesized by the electrostatic adsorption between AuNPs and SiO2-coated Fe3O4 NPs(SiO2@Fe3O4) and the amide bond between Au@SiO2@Fe3O4 and NG. L-Cysteine was successfully functionalized on the surface of Au@SiO2@Fe3O4/NG nanocomposites via the S―Au bond between L-cysteine and AuNPs. Owing to numerous active sites in L-cysteines and high conductivity of Au@SiO2@Fe3O4/NG composites, the proposed electrochemical sensor exhibited a well-distributed nanostructure and high responsivity toward Pb(II). The sensor linearly responded to Pb2+ concentration in the range of 5―80 μg/L with a detection limit of 0.6 μg/L, indicating that this L-cysteine functionalized Au@SiO2@Fe3O4/NG composite could be a promising candidate material for the detection of Pb2+.

Stripping analysis of Pb(II), Cd(II), Hg(II) and Cu(II) based on irradiated attapulgite/Ionic liquid composites

The individually and simultaneously detection of heavy metal ions have been widely reported. However, little analyzed the difference and relationship between the two such as sensitivities and limit of detection (LOD) using irradiated natural materials. Based on the electrochemical detection of Pb(II), Cd(II), Hg(II) and Cu(II) ions, their stripping behaviors, through combining an irradiated attapulgite (IAP) at a fluence of 30kGy (IAP30) with room temperature ionic liquid (RTIL) composites coated electrodes, were compared and analyzed by square wave stripping voltammetry. The characteristic of sensitivities and LOD of IAP30/RTIL electrode towards metal ions were markedly improved in comparison with IAP electrode. The LOD of the simultaneous detection towards Pb(II), Cd(II), Cu(II) and Hg(II) using IAP30/RTIL electrode were 0.8, 0.5, 0.2 and 0.06nM, respectively. The sensitivities and LOD of Pb(II), Cd(II) in simultaneous detection were lower and higher than these in individual detection, while those of Hg(II) and Cu(II) increased and decreased in comparison with the individual detection at IAP30/RTIL or IAP30 modified electrode. An enhanced sensitivity of Hg(II) in the simultaneous detection reached 242.4μA/μM, and was the largest among four metal ions. Analysis of six groups of solutions including Pb(II)-Cd(II)-Hg(II), Cd(II)-Cu(II)-Hg(II), Pb(II)-Cu(II)-Hg(II), Cu(II)-Hg(II), Pb(II)-Hg(II), Cd(II)-Hg(II) were further performed, respectively. This study provided a novel method for the construction of sensitive electrochemical sensors of heavy metal by natural materials, and an effective reference that meet the needs of environmental control for analysis of different metal ions.

Controlled synthesis various shapes Fe3O4 decorated reduced graphene oxide applied in the electrochemical detection

The various shapes Fe3O4 decorated reduced graphene oxide (Fe3O4/rGO) were prepared by one-step solution co-precipitation method, in which the shapes (sphere, rod and band) of Fe3O4 in the nanocomposites could be carefully controlled by adjusting the mole ratio of Fe2+/Fe3+ in the presence of rGO modified PVP. The structure of Fe3O4/rGO was characterized by SEM, EDS, TEM and Raman. Furthermore, the band Fe3O4/rGO modified glassy carbon electrode (GCE) was characterized by cyclic voltammetry (CV) and electrochemical impedance spectra (EIS). And the effect of shapes of Fe3O4 decorated reduced graphene oxide on the electrochemical detection of Pb(II) was investigated in detail. It was found that the shape of Fe3O4 had great effects on sensitivity. The band Fe3O4/rGO modified electrode toward Pb(II) showed high sensitivity (13.6μA/μM), which was higher than that of spherical and rod Fe3O4/rGO modified electrode, respectively. The band Fe3O4/rGO was further demonstrated to be useful for the individual electrochemical detection of Cd(II) and Cu(II) in water for the first time. This report provides an opportunity to study relationship between the shapes and properties of Fe3O4 decorated reduced graphene oxide with high performance.

Ultrasensitive and stable determination of lead ions by a glassy carbon electrode modified with a phenanthroline-based electropolymerized film

A novel electro-active compound, 3,8-bis(9,9-bis(6-(9H-carbazol-9-yl)hexyl)-9H-fluoren-2-yl)-1,10-phenanthroline (TCFC), is used to modify a glassy carbon electrode (GCE) for the electrochemical detection of Pb2+.

Performances of carbon-based screen-printed electrodes modified by diazonium salts with various carboxylic functions for trace metal sensors

The electrochemically induced functionalization of carbon-based screen-printed-electrodes (SPEs) by phenyl groups, having one or two carboxylic functions, was achieved by reduction of in situ generated diazonium salts in aqueous media. The corresponding diazonium cations of 4-aminobenzoic acid, 4-aminophthalic acid, 3-(4-aminophenyl) propionic acid, 3-(4-aminophenyl)-2-propenoic acid and 5-aminoisophthalic acid were generated in situ with sodium nitrite in aqueous H2SO4. The electrochemical detection of Pb(II) with the grafted SPEs was investigated using Pb(II) 5×10−8M solutions. The performances of the grafted SPEs were found to be dependent on the number of carboxylic groups, on their position on the phenyl ring, on the olefinic or the aliphatic character of the chain bearing the carboxylic group. The performances of mono-4-carboxyphenyl and 3,5-dicarboxyphenyl grafted SPEs for Cd(II) and Cu(II) trace detection were tested and compared.

Electrochemical Detection of Pb and Cu by Using DTPA Functionalized Magnetic Nanoparticles

Here, electrochemical determination of lead (Pb2+) and copper (Cu2+) ions, by using diethylenetriamine pentaacetic acid (DTPA) functionalized dopaminated Fe3O4 (Fe3O4/DA) magnetic nanoparticles, MNPs, (Fe3O4/DA/DTPA), is reported. First, step by step construction of Fe3O4/DA/DTPA was characterized and confirmed by spectroscopic methods. Then, a simple and new modified magnetic electrode was prepared by employing permanent magnet into a carbon paste electrode (MCPE) and collecting functionalized MNPs in each steps. The prepared modified electrodes, electrochemically characterized and further proofs was obtained in the presence of Fe(CN)6]3−/4− as a redox probe. Sensing ability of the modified electrodes toward two valet cations was evaluated by following striping voltammetry responses of pre-concentrated ions on top of them. The MCPE/Fe3O4/DA/DTPA electrode showed selective response to Pb2+ and Cu2+ ions. Consequently, the electrode response to Pb2+ and Cu2+ was evaluated as a function of solution pH, pre-concentration time, and ions concentrations. Finally, in optimized conditions, two linear ranges from 1.0×10−9 to 5.0×10−6 and 1.0×10−5 to 1.0×10−3 M Pb2+ with a detection limit (D.L.) of 7.8×10−10 M Pb2+, and a linear range from 5.0×10−9 to 1.0×10−3 M Cu2+ with a D.L. of 9.5×10−10 M Cu2+ were observed for separate determination of Pb2+ and Cu2+, respectively. Also, two linear ranges from 1.0×10−9 to 5.0×10−8 and 5.0×10−7 to 1.0×10−3 M Pb2+ with a D.L. of 8.2×10−9 M Pb2+, and a linear range from 5.0×10−9 to 1.0×10−4 M Cu2+ with a D.L. of 2.1×10−9 M Cu2+ were observed for simultaneous determination of Pb2+ and Cu2+. The obtained results will be presented and described here.

Electrochemical Detection of Pb(II) by Glassy Carbon Electrode Modified with Amine-Functionalized Magnetite Nanoparticles

An amine-Fe3O4 modified glassy carbon (GC) electrode was constructed for detecting Pb(II) ions in wastewater. The electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Square wave anodic stripping voltammetry (SWASV) was used to detect the Pb(II), and the detection limit of Pb(II) was 0.15 µM. The sensitivity of the electrode to detect Pb(II) was about 10.07 µA/µM, with a correlation coefficient of 0.991, which was approximately 10 times bigger than that of a pure Fe3O4 modified electrode. The electrode also showed good selectivity and stability. This results indicated that the amine-magnetite material could have some potential applications in heavy metal ions detection in wastewater.

Electrochemical detection of Pb and Cd in paper-based microfluidic devices

Filter paper strips combined with screen-printed carbon electrodes (SPCE) were used in the assembly of a microfluidic device for detecting Pb(II) and Cd(II) in aqueous samples. The portable microfluidic device (with direct electrochemical detection) was tested for direct quantification of multiple analytes (Pb(II) and Cd(II)) in contaminated aqueous samples without pretreatment. Square wave anodic stripping voltammetric (SWASV) signal was greatly enhanced and displayed excellent analytical performance for Pb(II) and Cd(II) detection (from 0 to 100 ppb) with low limit of detection of 2.0 and 2.3 ppb, respectively. The proposed electrochemical devices also exhibited good selectivity and stability for analyses of real samples of gas dissolved salty soda water and ground water with physical contamination. The device is simple, low-cost, easy-to-fabricate and portable. This analytical device has the possibility of being useful for point-of-care applications in environmental monitoring, public health and food safety.

Controllable luminescence and electrochemical detection of Pb2+ ion based on the 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonate) dye and dodecanesulfonate co-intercalated layered double hydroxide

2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonate) dye (ABTS) and dodecanesulfonate anion (SDS) have been co-intercalated into the ZnAl-layered double hydroxide (ZnAl LDH) matrix by a hydrothermal co-precipitation method, with obtained samples denoted as ABTS–SDS(x)/LDH (x stands for the molar percentage content of ABTS with respect to total intercalated content). The structure and chemical composition of the as-prepared compounds were characterized by X-ray diffraction (XRD), FT-IR spectra and elemental analysis. Fluorescence spectra demonstrated that the sample with 60% ABTS molar percentage, exhibited the optimal luminescent intensity. The fluorescence lifetime of ABTS in the gallery of LDH was enhanced significantly compared with that of pristine ABTS powder. As well, the ABTS–SDS/LDH thin film fabricated by the solvent evaporation method exhibited a well-defined c-orientation, which can be confirmed by XRD and scanning electron microscopy (SEM). Moreover, the ABTS–SDS(60%)/LDH film showed polarized luminescence (anisotropy: 0.35) and electrochemical response to aqueous solution containing Pb2+ ion. These results demonstrate that the ABTS–SDS/LDH system can serve as a good candidate for the solid-sate luminescence and electrochemical sensor materials.

Pb2+ induced DNA conformational switch from hairpin to G-quadruplex: electrochemical detection of Pb2+

Conformational switch from hairpin DNA to G-quadruplex induced by Pb(2+) is studied by electrochemical impedance spectroscopy (EIS) in the presence of [Fe(CN)(6)](3-/4-) as the redox probe. In the presence of Pb(2+), the G-rich hairpin DNA opens the stem-loop and forms G-quadruplex structure, which gives rise to a sharp increase in the charge-transfer resistance (R(CT)) of the film reflected by the EIS. This structural change is also confirmed by circular dichroism (CD) measurements and UV-Vis spectroscopic analysis and calculated by density functional theory (DFT). On the basis of this, we develop a label-free electrochemical DNA biosensor for Pb(2+) detection. With increasing concentrations of Pb(2+), the differences in the charge-transfer resistance R(CT) before and after the Pb(2+) incubation is linearly dependent on the logarithm of Pb(2+) concentration within a range from 50 μM to 0.5 nM. The biosensor also exhibits good selectivity for Pb(2+) over other metal ions. This is a simple and label-free electrochemical method for Pb(2+) detection making use of the G-quadruplex.