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1.
A Simple and Highly Sensitive Electrochemically Reduced p‐Nitrobenzoic Acid Film Modified Sensor for Determination of Mercury
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Herein, a simple electrochemical sensor was fabricated for sensing Hg2+ ions by using electrochemically reduced p‐nitrobenzoic acid molecules modified (ERpNBA) glassy carbon electrode (GCE). The modified electrode was applied for the determination of Hg2+ ions by using differential pulse anodic stripping voltammetry (DPASV). Experimental parameters such as concentration of p‐nitrobenzoic acid used for electrode modification, pH, accumulation time and deposition potential used for the determination of Hg2+ ions were optimized. The strong interaction between the Hg2+ ions and the lone pair of electrons on the nitrogen atoms of ERpNBA molecules leads to highly selective adsorption of Hg2+ ions on the modified electrode. Under the optimum experimental conditions, the sensor showed higher sensitivity and very low detection limit for Hg2+ ions than other metal ions such as Cd2+, Pb2+ and Zn2+ ions. The LOD for Hg2+ ions was 240 pM which is below the guideline value given by the World Health Organization and the earlier reports. 相似文献
2.
Ren-Xia Xu Xin-Yao Yu Chao Gao Yu-Jing Jiang Dong-Dong Han Jin-Huai Liu Xing-Jiu Huang 《Analytica chimica acta》2013
Nanostructured magnesium silicate hollow spheres, one kind of non-conductive nanomaterials, were used in heavy metal ions (HMIs) detection with enhanced performance for the first time. The detailed study of the enhancing electrochemical response in stripping voltammetry for simultaneous detection of ultratrace Cd2+, Pb2+, Cu2+ and Hg2+ was described. Electrochemical properties of modified electrodes were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The operational parameters which have influence on the deposition and stripping of metal ions, such as supporting electrolytes, pH value, and deposition time were carefully studied. The anodic stripping voltammetric performance toward HMIs was evaluated using square wave anodic stripping voltammetry (SWASV) analysis. The detection limits achieved (0.186 nM, 0.247 nM, 0.169 nM and 0.375 nM for Cd2+, Pb2+, Cu2+ and Hg2+) are much lower than the guideline values in drinking water given by the World Health Organization (WHO). In addition, the interference and stability of the modified electrode were also investigated under the optimized conditions. An interesting phenomenon of mutual interference between different metal ions was observed. Most importantly, the sensitivity of Pb2+ increased in the presence of certain concentrations of other metal ions, such as Cd2+, Cu2+ and Hg2+ both individually and simultaneously. The proposed electrochemical sensing method is thus expected to open new opportunities to broaden the use of SWASV in analysis for detecting HMIs in the environment. 相似文献
3.
Jinping Song Qi Ma Sufang Zhang Yong Guo Chuan Dong 《Journal of Cluster Science》2016,27(4):1203-1212
A rapid one-step preparation approach of silver nanoparticles (AgNPs) was reported by employing formamidinesulfinic acid as reducing agent and soluble starch as stabilizing agent. The formation of AgNPs was further confirmed by using UV–Vis absorption spectroscopy, X-ray diffraction spectroscopy and transmission electron microscopy techniques. The resultant AgNPs could be directly used for the colorimetric reaction with metal ions. The results showed that Al3+, Cr3+, Fe3+ and Hg2+ ions could induce the color change of AgNPs from yellow to pink (Al3+), orange (Cr3+) and colorless (Fe3+ and Hg2+), respectively, which can be observed by the naked eye. Based on these, a sensitive colorimetric sensor for Al3+, Fe3+, Cr3+ and Hg2+ ions detection was developed. 相似文献
4.
《Electroanalysis》2017,29(11):2423-2436
Herein, a facile procedure was developed for designing an electrochemical sensor based on pencil graphite electrode modified with electrochemically synthesized silver and copper nanoparticles (AgNP and CuNP) supported on functionalized multiwalled carbon nanotubes (f MWCNTs). The electrochemical and morphological characterization was carried out by cyclic voltammetry, Electrochemical Impedance Spectroscopy, Powder X‐ray diffraction, Field Emission Scanning Electron Microscopy, Transmission electron microscopy and Atomic Force Microscopy. The designed sensor exhibited electrocatalytic behavior towards the reduction of Imazethapyr. Results indicates the combination of AgNPs, CuNPs and f MWCNTs on PGE produced remarkable enhancement in electrocatalytic and sensing properties. Various electro‐kinetic parameters like Rct, kapp, n, α, E0, k0, Γ, D and k have been evaluated by CV, impedance and Chronoamperometric studies. The electrochemical performance was improved by optimizing the effect of pH, scan rate, amount of f MWCNTs and deposition parameters of AgNP and CuNP. The sensor was efficaciously applied for determination of Imazethapyr and exhibited a linear correlation in the concentration range of 0.01–5.0 μg mL−1 with low detection limits, 0.159 ng mL−1 using AdSWV. The fabricated sensor exhibited good accuracy, acceptable stability and high efficacy for quantitative determination of Imazethapyr in real samples with notable recoveries ranging from 98 % to 100.2 %. 相似文献
5.
Pencil graphite electrode (PGE) modified with MWCNT and Bi3+ (MWCNT/Bi/PGE) was utilized in simultaneous analysis of Pb2+, Cd2+, and Zn2+. Surface and electrochemical characteristics of MWCNT/Bi/PGE were investigated via SEM, cyclic voltammetry, electrochemical impedance spectroscopy, and FTIR measurements. Even though modification with MWCNT did not improve the electroactive surface area, it significantly decreased the charge transfer resistance. Furthermore, modification with Bi3+ significantly increased the sensitivity. Finally, MWCNT/Bi/PGE exhibited the highest sensitivity and reproducibility compared to PGE and PGE modified with only MWCNT. MWCNT/Bi/PGE provided LOD values of 0.27, 0.43, and 1.63 μg L−1, and linear ranges of 1–80, 5–80, and 10–80 μg L−1 for Pb2+, Cd2+, and Zn2+, respectively. Proposed modification method offers effective electroanalytical performance with low time consumption and cost for the analyst. 相似文献
6.
《Arabian Journal of Chemistry》2022,15(5):103780
The new application of C-dec-9-enylcalix[4]resorcinarene (R1), as an ionophore to detect heavy metals (HMs) cations (Cd2+, Hg2+, Cu2+, and Pb2+) in the aqueous media has been investigated through the preparation of an effective mass-sensitive sensor via the exploitation of a flow-type QCM-I technique. By adjusting the ions’ amounts in model solutions over a wide range of concentrations, acquired changes in the oscillating frequency related to the loading of metal ions on the sensor’s surface were gained, and thus favorable metrological parameters displaying the lowest detection limit (LOD) associated with copper ions (10 ppb). Simultaneously, a novel voltammetric sensor was prepared by modifying gold screen-printed electrodes (SPEs) with R1. Electrochemical characterization employing CV, SWV, and EIS was carried out, showing the success of the electrode modification. Then, the experimental conditions of supporting electrolyte, pH, accumulation time, and accumulation potential were optimized to achieve an enhanced detection. The R1@SPE sensor simultaneously detected the HMs (Cd2+, Hg2+, Cu2+, Pb2+), and the lowest LOD was associated with Pb2+ (0.19 ppb). The selectivity evaluation of the electrochemical sensor was performed by studying the effect of interferences majorly present in water sources (Mg2+, Ni2+, Zn2+, Al3+, and K+) on the SWV detection signals, and it was revealed that the interfering ions did not affect the simultaneous detection of the studied HMs (RSD less than 5%), the voltammetric sensors also presented excellent repeatability and reproducibility (RSD less than 5%). 相似文献
7.
Hui Xie Yanyan Niu Ying Deng Hui Cheng Chengxiang Ruan Guangjiu Li Wei Sun 《中国化学会会志》2021,68(1):114-120
In this paper, an electrochemical aptamer sensor was proposed for the highly sensitive detection of mercury ion (Hg2+). Carbon nanofiber (CNF) was prepared by electrospinning and high‐temperature carbonization, which was used for the loading of platinum nanoparticles (PtNPs) by the hydrothermal method. The Pt@CNF nanocomposite was modified on the surface of carbon ionic liquid electrode (CILE) to obtain Pt@CNF/CILE, which was further decorated by gold nanoparticles (AuNPs) through electrodeposition to get Au/Pt@CNF/CILE. Self‐assembling of the thiol‐based aptamer was further realized by the formation of Au‐S bond to get an electrochemical aptamer sensor (Aptamer/Au/Pt@CNF/CILE). Due to the specific binding of aptamer probe to Hg2+ with the formation of T‐Hg2+‐T structure, a highly sensitive quantitative detection of Hg2+ could be achieved by recording the changes of current signal after reacting with Hg2+ within the concentration range from 1.0 × 10?15 mol/L to 1.0 × 10?6 mol/L and the detection limit of 3.33 × 10?16 mol/L (3σ). Real water samples were successfully analyzed by this method. 相似文献
8.
Jikui Wu Lanying Li Bijun Shen Guifang Cheng Pingang He Yuzhi Fang 《Electroanalysis》2010,22(4):479-482
Polythymine oligonucleotide (PTO)‐modified gold electrode (PTO/Au) was developed for selective and sensitive Hg2+ detection in aqueous solutions. This modified electrode was prepared by self‐assembly of thiolated polythymine oligonucleotide (5′‐SH‐T15‐3′) on the gold electrode via Au? S bonds, and then the surface was passivated with 1‐mercaptohexanol solution. The proposed electrode utilizes the specific binding interactions between Hg2+ and thymine to selectively capture Hg2+, thereby reducing the interference from coexistent ions. After exchanging the medium, electrochemical reduction at ?0.2 V for 60 s, voltammetric determination was performed by differential pulse voltammetry using 10 mM HEPES; pH 7.2, 1 M NaClO4 as supporting electrolyte. This electrode showed increasing voltammetric response in the range of 0.21 nM Hg2+, with a relative standard deviation of 5.32% and a practical detection limit of 60 pM. Compared with the conventional stripping approach, the modified electrode exhibits good sensitivity and selectivity, and is expected to be a new type of green electrode. 相似文献
9.
Finly K. Arabbani Dhanapal Vasu Subramanian Sakthinathan Te-Wei Chiu Ming-Che Liu 《Electroanalysis》2023,35(3):e202200284
A novel electrochemical sensor on ZIF-8 nanocomposites (Ag/ZnO/ZIF-8) was developed to analyze the mercury ions (Hg2+). The ZIF-8 materials are one of the 3-dimensional porous metal-organic frameworks with highly accessible pores and great surface area. The ZIF-8 nanocomposites were prepared through simple sol-gel methods and their physio-chemical properties were characterized via different analytical analyses. As a result of cyclic voltammetry, Ag/ZnO/ZIF-8 exhibited a better electrocatalytic behavior towards the detection of mercury ions (Hg2+). Furthermore, the composite modified electrode was then inspected as a sensor for DPV detection of mercury ions. The nanocomposite sensor performed a wide linear range from 0.5 μM to 140 μM with a low detection limit of 40 nM, and high sensitivity of 56.06 μA μM−1 cm−2. Moreover, the ZIF-8 composite sensor showed a higher selectivity toward the detection of mercury ions (Hg2+). The real-time applications of the ZIF-8 composites sensor were inspected in various samples with good sensitivity. 相似文献
10.
A new sensor has been developed for the simultaneous detection of cadmium, lead, copper and mercury, using differential pulse and square wave anodic stripping voltammetry (DPASV and SWASV) at a graphite–polyurethane composite electrode with SBA‐15 silica organofunctionalized with 2‐benzothiazolethiol as bulk modifier. The heavy metal ions were preconcentrated on the surface of the modified electrode at ?1.1 V vs. SCE where they complex with 2‐benzothiazolethiol and are reduced to the metals, and are then reoxidized. Optimum SWASV conditions lead to nanomolar detection limits and simultaneous determination of Cd2+, Pb2+, Cu2+ and Hg2+ in natural waters was achieved. 相似文献
11.
In this paper, an electrochemical sensor was prepared based on the modification of pencil graphite electrode (PGE) by hollow platinum nanoparticles/reduced graphene oxide (HPtNPs/rGO/PGE) for determination of ceftazidime (CFZ). Initially, rGO was electrodeposited on the electrode surface, and then, hollow platinum nanoparticles were placed on the electrode surface via galvanic displacement reaction of Pt(IV) ions with cobalt nanoparticles (CoNPs) that had electrodeposited on the electrode surface. Several significant parameters controlling the performance of the HPtNPs/rGO/PGE were examined and optimized using central composite design as one optimization methodology. The surface morphology and elemental characterization of the bare PGE, rGO/PGE, CoNPs/rGO/PGE, and HPtNPs/rGO/PGE-modified electrodes was analyzed by field-emission scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and electrochemical impedance spectroscopy. The electrochemical activity of CFZ on resulting modified electrode was investigated by cyclic voltammetry (CV) and adsorptive differential pulse voltammetry (AdDPV). Adsorptive differential pulse voltammetry indicates that peak current increases linearly with respect to increment in CFZ concentration. CFZ was determined in the linear dynamic range of 5.0 × 10?13 to 1.0 × 10?9 M, and the detection limit was determined as 2.2 × 10?13 M using AdDPV under optimized conditions. The results showed that modified electrode has high selectivity and very high sensitivity. The method was used to determine of CFZ in drug injection and plasma samples. 相似文献
12.
Contamination of natural water by mercury (Hg2+) and bismuth (Bi3+) metal ions have been extensively studied due to their toxic effects. A validated square-wave anodic stripping voltammetry (SW-ASV) method for determining Bi3+ and Hg2+ ions individually and simultaneously is described. A new electrochemical sensor was constructed using a gold (Au) electrode that has been modified with poly(1,2-diaminoanthraquinone) (p-1,2-DAAQ). Scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy were used to characterize the p-1,2-DAAQ/Au modified electrode. Factors such as the polymer film thickness, electrolyte, square wave parameters and preconcentration conditions were optimized to improve the performance of the modified Au electrode. Good linear responses were achieved in the concentration ranges of 1–200 μg L−1 and 1–50 μg L−1 forBi3+ and Hg2+, respectively, and the limits of detection were 0.27 μg L−1 (Bi3+) and 0.29 μg L−1 (Hg2+). The interference study results illustrated the high selectivity of the modified electrode for detection of Bi3+ and Hg2+. The proposed SW-ASV method was successfully applied for Bi3+ and Hg2+analyses in different real water samples. 相似文献
13.
In this study; a sensitive, selective, and simple electrochemical sensor was developed to determine low concentration pyridoxine (Py) using a phosphorus-doped pencil graphite electrode (P-doped/PGE). Electrode modification was implemented using the chronoamperometry method at +2.0 V constant potential and 100 seconds in 0.1 mol L−1 H3PO4 supporting electrolyte solution. The characterization processes of the P-doped/PGE were carried out using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and atomic force microscope (AFM) methods. In the concentration study, using the differential pulse voltammetry (DPV) method, a linear calibration plot was acquired in the concentration range of 0.5 to 300 μmol L−1 Py. The limit of quantification (LOQ) and limit of detection (LOD) of the developed method were calculated as 0.219 μmol L−1 and 0.0656 μmol L−1, respectively. Detection of Py has been successfully performed on the P-doped/PGE in the beverage samples. As a result, the method developed has been shown to have fast, low cost, and simple for the sensitive and selective detection of Py as an effective electrode. 相似文献
14.
Here we report the characterization of an electrochemical mercury (Hg2+) sensor constructed with a methylene blue (MB)-modified and thymine-containing linear DNA probe. Similar to the linear probe electrochemical DNA sensor, the resultant sensor behaved as a “signal-off” sensor in alternating current voltammetry and cyclic voltammetry. However, depending on the applied frequency or pulse width, the sensor can behave as either a “signal-off” or “signal-on” sensor in square wave voltammetry (SWV) and differential pulse voltammetry (DPV). In SWV, the sensor showed “signal-on” behavior at low frequencies and “signal-off” behavior at high frequencies. In DPV, the sensor showed “signal-off” behavior at short pulse widths and “signal-on” behavior at long pulse widths. Independent of the sensor interrogation technique, the limit of detection was found to be 10 nM, with a linear dynamic range between 10 nM and 500 nM. In addition, the sensor responded to Hg2+ rather rapidly; majority of the signal change occurred in <20 min. Overall, the sensor retains all the characteristics of this class of sensors; it is reagentless, reusable, sensitive, specific and selective. This study also highlights the feasibility of using a MB-modified probe for real-time sensing of Hg2+, which has not been previously reported. More importantly, the observed “switching” behavior in SWV and DPV is potentially generalizable and should be applicable to most sensors in this class of dynamics-based electrochemical biosensors. 相似文献
15.
Ozge Gorduk 《Electroanalysis》2021,33(5):1378-1388
In this study, we present a strategy for the specific electrochemical detection of NADH in human blood serums using modified electrode fabricated by intercalation of tetrabutylammonium ions (TBA+) into pencil graphite electrode (TBA+/PGE). In order to implement this protocol, a modification process in the potential range (−0.2) to (−2.75) V was performed in DMSO containing 0.1 M TBAP by CV method. The characterization processes of the prepared sensor were carried out using CV, EIS, FT-IR, XPS, and SEM methods. The electrode fabricated by intercalation of TBA+ was found to be able to analyze NADH at +0.32 V applied potential by the amperometric method. The LOD was detected as 0.46 μM. The analysis results of human blood serums which are taken from healthy individuals show that TBA+/PGE can be used for real samples. The results indicated that TBA+/PGE can be easily fabricated by one-step and one-pot electrochemical method and TBA+/PGE can be used as a potential sensor for the NADH determination. 相似文献
16.
《Electroanalysis》2017,29(2):345-351
A glassy carbon electrode modified with reduced graphene oxide and platinum nanocomposite film was developed simply by electrochemical method for the sensitive and selective detection of nitrite in water. The electrochemical reduction of graphene oxide (GO) efficiently eliminates oxygen‐containing functional groups. Pt nanoparticles were electrochemically and homogeneously deposited on the ErGO surface. Field emission scanning electron microscopy (FE‐SEM), Raman spectroscopy, attenuated total reflectance‐fourier transform infrared spectroscopy (ATR‐FTIR), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) were used to examine the surface morphology and electrocatalytic properties of the Pt‐ErGO nanocomposite film‐modified electrode surface. The fabricated nitrite sensor showed good electrochemical performance with two linear ranges; one from 5 to 100 µM (R2=0.9995) and the other from 100 to 1000 µM (R2=0.9972) and a detection limit of 0.22 µM. The proposed sensor was successfully applied for the detection of nitrite in tap water samples which proves performance of the Pt‐ErGO nanocomposite films. 相似文献
17.
Farzaneh Nourifard Mahmood Payehghadr 《International journal of environmental analytical chemistry》2016,96(6):552-567
A new chemically modified carbon paste electrode by 2,2?-((pyridine-2,6-diylbis(azanylylidene))bis(methanylylidene))diphenol (L) ligand has been made and used as a sensor for determination of trace mercury and cadmium ions with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. Complexation studies of the ligand with Cu2+, Zn2+, Hg2+, Ni2+ and Cd2+ ions by conductometric method in acetonitrile–ethanol mixture at 25°C show that the ML complexes have formed. The formation constants of complexes were calculated from the computer fitting of the molar conductance–mole ratio data, and the stability of the resulting complexes varied in order of Cd2+ > Hg2+ > Cu2+ > Zn2+ > Ni2+. Then a simple and effective chemically modified carbon paste electrode with L was prepared, and the electrochemical properties and applications of the modified electrode were investigated. Under the optimal conditions, the detection limit was 0.0494 μg L?1 and 0.0782 μg L?1 for cadmium and mercury ions, respectively, and the linear range for both metal ions were from 1 to 100 μg L?1. The electrode shows high sensitivity, reproducibility and low cost, and was successfully applied to determination of Cd2+ and Hg2+ ions in water samples with recovery in the range of 97–101%. 相似文献
18.
Aptamer–silver nanoparticles (AgNPs) based surface-enhanced Raman scattering (SERS) sensor has been developed for Hg2+ detection by employing the structure-switching aptamer in the presence of spermine. This simple method shows excellent sensitivity and selectivity owing to the sensitive SERS detection technique and high specificity of aptamer for binding Hg2+. 相似文献
19.
In this article, we present a simple and efficient method to synthesize a magnetic NiFe2O4 nanocatalyst under hydrothermal conditions. Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X‐ray spectroscopy (EDX) analyses confirmed the synthesis of NiFe2O4 nanoparticles. These nanoparticles showed satisfactory catalytic activity for determination of norepinephrine (NE) in the presence of folic acid (FA) using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. Differential pulse voltammetry peak currents of NE increased linearly with their concentrations in the range of 1.0 × 10?7–5.0 × 10?4 M, and the detection limit for NE was 2.3 × 10?8 M, respectively. The modified electrode displayed strong function for resolving the overlapping voltammetric responses of NE and FA into two well‐defined voltammetric peaks. In the mixture containing NE and FA, the two compounds can well separate from each other with a potential difference of 510 mV between NE and FA, which was large enough to determine NE and FA individually and simultaneously. Additionally, the prepared electrochemical sensor demonstrated a practical feasibility for real sample determination. 相似文献
20.
J. Albaiges 《International journal of environmental analytical chemistry》2013,93(9):671-680
Inorganic mercury ions (Hg2+) in laboratory prepared solutions were determined with a screen-printed carbon electrode (SPCE) coated with a polyaniline-methylene blue (PANI-MB) polymer layer. The structure and properties of the PANI-MB polymer layer were compared to that of normal polyaniline (PANI) in order to elucidate the structure of the PANI-MB layer. The electrically-conducting polymers were prepared by electrochemical polymerisation of monomer solutions of aniline, and mixed solutions of aniline with methylene blue onto respective screen-printed carbon electrodes (SPCEs). Scanning Electron Microscopy (SEM) analyses of the SPCE polymer coated electrodes have shown that nanostructured materials have formed with the diameters of the PANI nanoclusters and PANI-MB nanorods at approximately 200 nm. Anodic stripping voltammetry (ASV) was used to evaluate a solution composed of 1 × 10?6 M Hg2+, in the presence of the SPCE/PANI-MB polymer sensor electrode. The Hg2+ ions were determined as follows: (i) pre-concentration and reduction on the modified electrode surface and (ii) subsequent stripping from the electrode surface during the positive potential sweep. The experimental conditions optimised for Hg2+ determination included the supporting electrolyte concentration and the accumulation time. The results obtained have shown that the SPCE/PANI-MB polymer sensor electrode operates optimally at a pH 2, with the supporting electrolyte concentration at 0.5 M HCl. A linear calibration curve was found to be in the range of 1 × 10?8 M to 1 × 10?5 M Hg2+ after 120 s of pre-concentration. The detection limit was calculated and found to be 54.27 ± 3.28 µg L?1 of Hg2+. The results have also shown that a conducting polymer modified SPCE sensor electrode can be used as an alternative transducer for the voltammetric stripping and analysis of inorganic Hg2+ ions. 相似文献