Glassy Carbon Electrodes Modified with Ordered Mesoporous Silica for the Electrochemical Detection of Cadmium Ions (original) (raw)
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Sensors and Actuators B: Chemical, 2011
This study reports the electrochemical modification of glassy carbon (GC) electrode surface with the electro-polymerized form of 1,10-phenanthroline monohydrate (PMH), the characterization of this polyphenanthroline modified electrode (PPMH/GC) and the electroanalytical application suitable for the determination of Cd(II) ions. The PPMH/GC electrode was characterized by cyclic voltammetry, chronoamperometry and atomic force microscopy and formation of polyphenanthroline layer grafted to surface of GC electrode was evidenced. Selectivity of PPMH/GC electrode towards heavy metal ions was investigated by square wave voltammetry. The PPMH/GC electrode was found to be suitable for selective determination of Cd(II) in the solutions containing the mixture of heavy metal ions and showed high stability and reproducibility. The analytical methodology was successfully applied for monitoring the toxic metal ions in real samples.
ACS Omega
Cbz-APL) tripeptide-coated glassy carbon electrode (GCE)-based sensor was used for sensitive and selective recognition of cadmium ions in environmental water. Detailed cyclic voltammetric and electrochemical impedance spectroscopic studies were performed to investigate the charge transfer and sensing activity of the developed electrochemical sensor. Square wave anodic stripping voltammetry (SWASV) was employed to further investigate the sensitivity, selectivity, validity, and applicability of the developed sensor. A sharp electrochemical signal of oxidized Cd at −0.84 V versus Ag/AgCl provides evidence for the higher sensing ability of Cbz-APL/GCE than bare GCE at −0.79 V. Moreover, on Cbz-APL/GCE, extraordinary low detection limits of 4.34 fM and linearity range of 15 nM to 0.1 pM with coefficients of correlation higher than 0.99 for Cd 2+ were achieved. Besides, the influence of inorganic and organic interferents on the targeted analyte signals was examined, and high selectivity of Cbz-APL/GCE for Cd 2+ ions was observed. Lastly, the validity and applicability of the developed electrochemical sensor for the detection of Cd 2+ ions were checked in real water samples, and 100% recovery was obtained.
Talanta, 2003
The determination of cadmium using a carbon paste electrode modified with organofunctionalized amorphous silica with 2-benzothiazolethiol was investigated. The Cd(II) oxidation peak was observed around (/0.80 V (vs. SCE) in phosphate buffer (pH 4.0) in differential pulse anodic stripping voltammetry. The best results were obtained under the following optimized conditions: 1 min accumulation time, 50 mV pulse amplitude, 20 mV s (1 scan rate in phosphate buffer pH 4.0. Using such parameters a linear dynamic range from 5.6)/10 (7 to 3.5)/10 (5 mol l (1 Cd(II) was observed with a sensitivity of 2.83 mA mol (1 l, limit of detection 1.0)/10 (7 mol l (1. Cd(II) spiked in a natural water sample was determined with 99% mean recovery at 10 (7 mol l (1 level. Interference were also evaluated.
Journal of the Brazilian Chemical Society, 2007
The performance of a carbon paste electrode (CPE) modified with SBA-15 nanostructured silica organofunctionalised with 2-benzothiazolethiol in the simultaneous determination of Pb(II), Cu(II) and Hg(II) ions in natural water and sugar cane spirit (cachaça) is described. Pb(II), Cu(II) and Hg(II) were pre-concentrated on the surface of the modified electrode by complexing with 2-benzothiazolethiol and reduced at a negative potential (−0.80 V). Then the reduced products were oxidised by DPASV procedure. The fact that three stripping peaks appeared on the voltammograms at the potentials of −0.48 V (Pb 2+ ), −0.03 V (Cu 2+ ) and +0.36 V (Hg 2+ ) in relation to the SCE, demonstrates the possibility of simultaneous determination of Pb 2+ , Cu 2+ and Hg 2+ . The best results were obtained under the following optimised conditions: 100 mV pulse amplitude, 3 min accumulation time, 25 mV s −1 scan rate in phosphate solution pH 3.0. Using such parameters, calibration graphs were linear in the concentration ranges of 3.00-70.0 × 10 −7 mol L −1 (Pb 2+ ), 8.00-100.0 × 10 −7 mol L −1 (Cu 2+ ) and 2.00-10.0 × 10 −6 mol L −1 (Hg 2+ ). Detection limits of 4.0 × 10 −8 mol L −1 (Pb 2+ ), 2.0 × 10 −7 mol L −1 (Cu 2+ ) and 4.0 × 10 −7 mol L −1 (Hg 2+ ) were obtained at the signal noise ratio (SNR) of 3. The results indicate that this electrode is sensitive and effective for simultaneous determination of Pb 2+ , Cu 2+ and Hg 2+ in the analysed samples.
Journal of Analytical Methods in Chemistry
The present study introduces a novel electrode for rapid, highly sensitive, and selective electrochemical sensor for cadmium(II) using 5% N1-hydroxy-N1,N2-diphenylbenzamidine (HDPBA) modified carbon paste electrode (CPE) (HDPBA‒CPE). Surface characterizations and structural analysis of the proposed HDPBA‒CPE were performed using several analytical techniques. The voltammetric measurements of Cd(II) were conducted by cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV). Several experimental conditions such as composition and pH of buffer solutions, HDPBA composition, accumulation potential and time, and other voltammetric conditions were optimized. Cd(II) was preconcentrated on the modified electrode surface for 270 s using Britton Robinson (B-R) buffer (0.1 M, pH 4) at −1.0 V versus Ag/AgCl, followed by electrochemical oxidation of the accumulated Cd(II) in the positive scan of SWASV after a quiet time of 10 s. Under optimized parameters, the proposed method ...
Water Air and Soil Pollution, 2020
The development of methods for lead ion determination in various biological and environmental samples is both necessary and challenging. In this context, considering the properties of both SBA-15 and MCM-41 mesoporous materials and the role of NH 2functional groups grafted on the silica surface (SBA-15-NH 2 and MCM-41-NH 2), the aim of the study was to investigate the electrochemical detection of Pb 2+ by means of silica-modified glassy carbon electrodes (GCEs). The square wave anodic stripping voltammetry (SWASV) was used to characterize the modified electrodes with four different samples of ordered mesoporous silica (OMS) powders, mentioned above. Additionally, scanning electron microscopy (SEM) was used to characterize these modifiers. Pb 2+ exhibits a well-defined oxidation peak (around − 0.5 V vs. Ag/AgCl/ KCl sat) and high peak current at either bare or OMSmodified glassy carbon electrodes, but the best response was recorded in the case of GC/SBA-15-NH 2-modified electrode in 0.1 M acetate buffer. The performance of the prepared electrodes is highlighted by good analytical parameters (satisfies the requirements of low cost and rapid results), which recommends them to be used for real sample analysis.
2020
A novel chemically modified carbon paste electrode (CMCPE) impregnated with 4′-(4-chlorophenyl)-2,2′:6′,2′′-terpyridine ligand was prepared and applied for voltammetric determination of Cd2+ ion in petrochemical samples. The effects of pH, ligand amount and supporting electrolyte on the selective adsorption properties for the Cd2+ ion were explored. The sensor displayed substantially good resistance against interfering agents. In the presence of a large excess of Na+, K+, Ca2+, Mg2+ and Pb2+, the adsorption capacity for Cd2+ was slightly changed, suggesting the high selectivity of CMCPE for Cd2+ions. The parameters controlling the response of the electrode were investigated. The limit of detection (LOD) and relative standard deviation (n = 5) were obtained by 3.77 ng/Land 0.45%, respectively. The preconcentration procedure revealed a linear curve within the concentration range of 4 – 3000 ng/L and a good linearity with squared correlation coefficient of (R2) 0.9988 was achieved. The...
Development of Cd 2+ sensor based on BZNA/Nafion/Glassy carbon electrode by electrochemical approach
Chemical Engineering Journal , 2018
A new electrochemical sensor for the selective detection of Cd 2+ ion based on Schi ff base, 1,1 ′ -(biphenyl-4,4 ′ -diylbis(azan-1-yl-1-ylidene))bis(methan-1-yl-1-ylidene) dinaphthalen-2-ol (BZNA) having from both moieties 2-hydroxy-1-iminomethylnaphthalene and benzidine core is presented. BZNA was synthesized by condensationreaction and then fully characterized. A thin lm of BZNA was fabricated onto Na on/Glassy carbon electrode(GCE) with 5.0% ethanolic solution of Na on as the conducting coating agent. A slurry of BZNA was used to coatthe GCE (GCE; 0.0316cm 2 ) as a thin layer for the selective detection of Cd 2+ ion in an aqueous solution. A linearcalibration curve that has a linear dynamic range (LDR) from 0.1nM to ∼ 0.1mM is obtained. From the slope of the plot, the calculated sensitivity, limit of detection (LOD), and limit of quanti cation (LOQ) of Cd 2+ ion werefound to be 2.93µAµM − 1 cm − 2 , 32.0 ± 1.62pM, and 106.67pM respectively. This novel approach might pavethe way for the development of heavy metal ion detection process in the elds of environmental and healthcare.
A sensitive voltammetric method has been developed for the determination of cadmium(II) utilizing a carbon paste electrode modi®ed with N-p-chlorophenylcinnamohydroxamic acid. The analyte was accumulated at the modi®ed electrode surface (via complexation) under open circuit and precisely controlled convective condition. It was then quanti®ed electrochemically by differential pulse anodic stripping voltammetry in a different nondeaerated electrolyte solution following medium exchange. Detailed experiments were conducted to establish the optimal carbon paste composition, pH and concentration of accumulation and stripping solutions, preconcentration time, bulk cadmium(II) concentration, and instrumental parameters. Two good linearities were obtained between the voltammetric current and cadmium concentration employing different preconcentration times. One was acquired in the concentration range 2.00610 77 ±3.20610 76 M Cd(II) (r 0.999) and the other from 4.00610 78 to 1.60610 77 M Cd(II) (r 0.999) with 1 min and 2 min preconcentration time, respectively. The detection limit was found to be 9.80610 79 M (1.1 ppb) Cd(II) with 2 min preconcentration time. For a series of six determinations of Cd(II) at 1610 76 M and 8610 78 M levels relative standard deviations of 2.6% and 5.5%, respectively, were achieved. Electrochemical cleaning was used to regenerate the surface rapidly and reproducibly; and this allows the use of a single modi®ed electrode surface in multiple analytical determinations over several weeks. Many common metal ions had little or no effect on the determination of cadmium(II). The method was veri®ed by the determination of trace cadmium(II) in municipal and mineral waters.