Reagentless, Electrochemical Aptasensor for Lead (II) Detection

2017 ◽  
Vol 20 (1) ◽  
pp. 001-005 ◽  
Author(s):  
Yan Lin ◽  
Lin Cheng ◽  
Guo Bing Wei ◽  
Ling Ling He ◽  
Cha Dan Chen ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Electrochemical Impedance ◽  
Chinese Herb ◽  
Amperometric Detection ◽  
Differential Pulse ◽  
Random Coil ◽  
Lead Ion ◽  
Sensitivity And Selectivity ◽  
One Step ◽  
Novel Strategy

A novel strategy for selective and sensitive amperometric detection of lead ion (Pb2+) was proposed based on target-inducedconformational switch. The ferrocene-labeled aptamer thiol was self-assembled through S-Au bonding on a gold electrode surface and thesurface was blocked with 2-mercaptoethanol to form a mixed monolayer. The aptamer-modified electrode was characterized electrochemicallyby differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The modified electrode showed a voltammetricsignal due to a one-step redox reaction of the surface-confined ferrocenyl moiety of the aptamer immobilized on the electrodesurface in 20mM Tris–HCl buffers buffer of pH 7.4. The “signal-on” upon Pb2+ association could be attributed to a change in conformationfrom random coil-like configuration on the probe-modified film to the quadruplex structure. The fabricated biosensor showed alinear response to the logarithm of Pb2+ concentration over the range of 5.0×10-10 M to 1.0×10-7 M with a detection limit of 1.2×10-10 M.In addition, this strategy afforded an exquisite selectivity for Pb2+ against other metal ions. The excellent sensitivity and selectivity showgood potential for Pb2+ detection in real Chinese herb samples.

An Amperometric Immunosensor for α-Fetoprotein Based on Antibody Coated Nano ZrO2-Au-Poly Lysine Composite Membrane Modified Electrode

2011 ◽  
Vol 343-344 ◽  
pp. 490-496 ◽  
Author(s):  
Yuan Zhao Wu ◽  
Fu Tao Hu ◽  
Ning Gan ◽  
Jian Guo Hou ◽  
Tian Hua Li ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Composite Membrane ◽  
Electrochemical Impedance ◽  
Signal To Noise Ratio ◽  
Cost Effective ◽  
Differential Pulse ◽  
Phenoxyacetic Acid ◽  
Serum Samples ◽  
Amperometric Immunosensor ◽  
Sensitivity And Selectivity

One novel amperometric immunosensor for α-fetop- rotein was fabricated which was modified by antibody immobilized on nano ZrO2-Au-polyLysine composite membrane. Firstly, the deoxyribonucleic acid – phenoxyacetic acid isoniazid- Schiff base Co(II) complex (DNA-CoL) mixture film was casted on surface of multi carbon nanotubes(MWCNTs) modified glassy carbon electrode(GCE/CNTs/DNA-CoL). Then the composite nanoparticles (ZrO2-Au-pLL) was employed to immobilize the antibody of α-fetoprotein(AFP) to produce the probes(ZrO2-Au-pLL-anti AFP) for AFP. Finally the probes were modified on GCE/CNTs/DNA-CoL through the specific connection between DNA and ZrO2 to form a novel nanocomposite membrane immunosensor for AFP(GCE/CNTs/ DNA-CoL/ZrO2-Au–pLL-anti AFP). The function of immunosensor was investigated by scanning electron microscopy (SEM), cyclic voltammetry(CV), differential pulse voltammety (DPV) and electrochemical impedance spectroscopy experiment (EIS). The results indicated that combining the advantages of the MWNTs-DNA material and ZrO2-Au-pLL-anti AFP nano probes, the immunosensor with excellent sensitivity and selectivity to AFP was prepared successfully. The modified electrode was sensitive to AFP with a linear relationship between 0.05 and 10 ng · mL−1 and a correl- ation coefficient of 0.9905. The detection limit at a signal to noise ratio of 3 was 0.01 ng·mL−1 under the optimal conditions. The described immunosensor preparation and immunoassay methods offer promise for simple and cost-effective analysis of AFP in serum samples.

scholarly journals Highly Sensitive Detection of Dopamine at Ionic Liquid Functionalized RGO/ZIF-8 Nanocomposite-Modified Electrode

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Lei Cheng ◽  
Youjun Fan ◽  
Xingcan Shen ◽  
Hong Liang
Keyword(s):  
Ionic Liquid ◽  
Modified Electrode ◽  
Electrocatalytic Activity ◽  
Electrochemical Impedance ◽  
Modified Electrodes ◽  
Differential Pulse ◽  
Zeolitic Imidazolate Framework ◽  
Response Range ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

A hybrid and hierarchical nanocomposite was successfully prepared by the growth of zeolitic imidazolate framework-8 (ZIF-8) on the template of ionic liquid (IL, [Bmim][BF4]) functionalized reduced graphene oxide (IL-RGO). The structure and morphology of the IL-RGO/ZIF-8 nanocomposite were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FTIR), and Raman spectroscopy. The results showed that RGO sheets were refrained from restacking by IL, and ZIF-8 nanoparticles grew well on the surface of IL-RGO. Owing to the synergistic effect from large surface area and excellent electrocatalytic activity of ZIF-8 and great electrical conductivity of IL-RGO, a highly sensitive sensor for dopamine (DA) can be obtained. IL-RGO/ZIF-8-modified electrode exhibits good electrocatalytic activity and electroconductive properties towards DA which were investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Compared with bare or IL-RGO-modified electrodes, the IL-RGO/ZIF-8-modified electrode effectively depressed the oxidation overpotential of DA. The linear response range of DA was from 1.0×10−7 to 1.0×10−4 mol/L with a low detection of limit 3.5×10−8 mol/L. In addition, the sensor was shown to provide satisfactory stability for the determination of DA.

scholarly journals Novel Electrochemical Sensor Fabricated for Individual and Simultaneous Ultrasensitive Determination of Olaquindox and Carbadox Based on MWCNT-OH/CMK-8 Hybrid Nanocomposite Film

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3041 ◽  
Author(s):  
Yanqing Liu ◽  
Gengxin Hu ◽  
Hongwu Wang ◽  
Su Yao ◽  
Yinjian Ye
Keyword(s):  
Electrochemical Sensor ◽  
Simultaneous Determination ◽  
Modified Electrode ◽  
Electrochemical Impedance ◽  
Modified Electrodes ◽  
Differential Pulse ◽  
Hybrid Nanocomposite ◽  
Experimental Conditions ◽  
Linear Relationships

A hybrid nanocomposite consisting of hydroxylated multi-walled carbon nanotubes (MWCNTs−OH) and cube mesoporous carbon (CMK−8) was applied in this study to construct an MWCNT−OH/CMK−8/gold electrode (GE) electrochemical sensor and simultaneously perform the electro-reduction of olaquindox (OLA) and carbadox (CBX). The respective peak currents of CBX and OLA on the modified electrode increased by 720- and 595-fold relative to the peak current of GE. The performances of the modified electrode were investigated with electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry. Then, the modified electrodes were used for the individual and simultaneous determination of OLA and CBX. The fabricated sensor demonstrated a linear response at 0.2–500 nmol/L in optimum experimental conditions, and the detection limits were 104.1 and 62.9 pmol/L for the simultaneous determination of OLA and CBX, respectively. As for individual determination, wide linear relationships were obtained for the detected OLA with levels of 0.05–500 nmol/L with LOD of 20.7 pmol/L and the detected CBX with levels of 0.10–500 nmol/L with LOD of 50.2 pmol/L. The fabricated sensor was successfully used in the independent and simultaneous determination of OLA and CBX in spiked pork samples.

scholarly journals Carbon nanotube-ionic liquid nanocomposite modified carbon-ceramic electrode for determination of dopamine in real samples

2013 ◽  
Vol 11 (7) ◽  
pp. 1172-1186 ◽  
Author(s):  
Mir Majidi ◽  
Reza Baj ◽  
Abdolhossein Naseri
Keyword(s):  
Ionic Liquid ◽  
Carbon Nanotube ◽  
Modified Electrode ◽  
Electrochemical Impedance ◽  
Differential Pulse ◽  
Selective Determination ◽  
Carbon Ceramic Electrode ◽  
Electro Oxidation ◽  
Carbon Ceramic

AbstractRoom temperature 1-butyl-3-methylimidazolium tetraflouroborate ([BMIM][BF4]) ionic liquid was employed for dispersion of multi walled carbon nanotubes (MWCNTs) and the formation of nanocomposite on the surface of a carbon-ceramic electrode. The surface of the modified electrode was characterized using scanning electron microscopy and electrochemical impedance spectroscopy. The modified electrode exhibited excellent electrochemical activity to oxidation of dopamine (DA); whereas electro oxidation of ascorbic acid (AA) was not seen and electro oxidation of uric acid (UA) appeared at a more positive potential than DA. The multi walled carbon nanotube-ionic liquid nanocomposite modified carbon-ceramic electrode was used for the selective determination of DA in the presence of high levels of AA and UA using differential pulse voltammetry. The calibration curve for DA was linear in the range of 3.00 to 130 µM with the detection limit (S/N=3) of 0.87 µM. The present electrode was successfully applied to the determination of DA in some commercial pharmaceutical samples and human blood serum.

scholarly journals Sensor Based on a Poly[2-(Dimethylamino)ethyl Methacrylate-Co-Styrene], Gold Nanoparticles, and Methylene Blue-Modified Glassy Carbon Electrode for Melamine Detection

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2850
Author(s):  
Fairouz Aberkane ◽  
Imene Abdou ◽  
Nadia Zine ◽  
Nicole Jaffrezic-Renault ◽  
Abdelhamid Elaissari ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Gold Nanoparticles ◽  
Impedance Spectroscopy ◽  
Glassy Carbon Electrode ◽  
Modified Electrode ◽  
Glassy Carbon ◽  
Electrochemical Impedance ◽  
Differential Pulse ◽  
Carbon Electrode ◽  
Detection Range

Melamine has been used as a non-protein nitrogenous additive in food products to artificially increase the apparent “false” protein content. Melamine is known as a dangerous and poisonous substance for human health and it causes diverse diseases. An electrochemical sensor for melamine detection has been developed by modification of a glassy carbon electrode using copolymer poly[DMAEMA-co-styrene], gold nanoparticles, and methylene blue. The characterization of the modified electrode was conducted using several analysis techniques including cyclic voltammetry (CV), differential pulse voltammetry (DPV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). The electrochemical detection of melamine was performed by impedance spectroscopy. Obtained results revealed that the developed sensor has a large detection range from 5.0 × 10−13 to 3.8 × 10−8 M with a low detection limit of 1.8 × 10−12 M (at S/N = 3). Various interfering species such as phenol, hydroquinone, and bisphenol A have been used and their behavior on modified electrode has been studied.

scholarly journals Development of a Carbon Paste Electrode Containing Benzo-15-Crown-5 for Trace Determination of the Uranyl Ion by Using a Voltammetric Technique

2009 ◽  
Vol 92 (1) ◽  
pp. 241-247 ◽  
Author(s):  
Sunil K Agrahari ◽  
Sangita D Kumar ◽  
Ashwini K Srivastava
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Modified Electrode ◽  
Carbon Paste Electrode ◽  
Electrochemical Impedance ◽  
Differential Pulse ◽  
Carbon Paste ◽  
Pulse Voltammetry ◽  
Paste Electrode

Abstract The interaction of macrocyclic compounds like crown ethers and UO22+ has been studied by electrochemical methods. A modified carbon paste electrode incorporating benzo-15-crown-5 (B15C5) was used to evaluate the electron transfer reaction of UO22+ by cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. Electrochemical impedance studies showed that charge transfer resistance was less for the B15C5-modified electrode than for the plain carbon paste electrode (PCPE). On the basis of these observations, a UO22+-sensitive crown ether chemically modified electrode (CME) for trace analysis was fabricated and investigated in aqueous solutions. It was found that a 5 B15C5CME for UO22+ showed a better voltammetric response than did the PCPE. UO22+ could be quantified at sub-μg/mL levels by differential pulse voltammetry with a detection limit of 0.03 μg/mL. By differential pulse adsorptive stripping voltammetry, UO22+ could be quantified in the working range of 0.002-0.2 μg/mL, with a detection limit of 1.1 μg/L. Simultaneous determination of UO22+, Pb2+, and Cd2+ was possible. The method was successfully applied to the determination of UO22+ in synthetic, as well as real, samples; the results were found to be comparable to those obtained by inductively coupled plasma-atomic emission spectroscopy.

A novel strategy for the detection of tert-butylhydroquinone based on graphene quantum dots and silver nanoparticle modified glass carbon electrode

2015 ◽  
Vol 93 (6) ◽  
pp. 648-654 ◽  
Author(s):  
Xiuli Niu ◽  
Wu Yang ◽  
Hao Guo ◽  
Jie Ren ◽  
Jing Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electron Transfer ◽  
Modified Electrode ◽  
Silver Nanoparticle ◽  
Graphene Quantum Dots ◽  
Surface Concentration ◽  
Glass Carbon Electrode ◽  
Glass Carbon ◽  
One Step ◽  
Novel Strategy

Graphene quantum dots (GQDs) were synthesized by a facile one-step wet chemically derived from carbon fibers. A novel, sensitive, simple, and convenient method for the detection of tert-butylhydroquinone (TBHQ) was established based on GQDs and silver nanoparticle (AgNP) modified electrode. The modified electrode exhibited excellent electrocatalytic performance toward the electrochemical detection of TBHQ. Meanwhile, a possible reaction mechanism related to the oxidation of TBHQ was proposed. The electron transfer number and electron transfer coefficient were found to be 3.05 and 0.40. The surface concentration of TBHQ on GQD/AgNP-modified electrode was calculated as 2.62 × 10−10 mol cm−2. Under the optimum conditions, a good linear relationship between peak current and the concentration of TBHQ was obtained in the range of 0.15–300 μmol L–1 with a detection limit of 0.07 μmol L–1 (S/N = 3). The proposed method was successfully applied for the detection of TBHQ in edible vegetable oil.

Differential Pulse Voltammetric Determination of Piroxicam on Lanthanide Ferric Oxide Nanoparticles-Carbon Paste Modified Electrode

2018 ◽  
Vol 14 (3) ◽  
pp. 271-276 ◽  
Author(s):  
Isaac Yves Lopes de Macedo ◽  
Morgana Fernandes Alecrim ◽  
Luane Ferreira Garcia ◽  
Aparecido Ribeiro de Souza ◽  
Wallans Torres Pio dos Santos ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Ferric Oxide ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Oxide Nanoparticles ◽  
Carbon Paste ◽  
Carbon Paste Modified Electrode

scholarly journals Electrochemical Investigation of Curcumin–DNA Interaction by Using Hydroxyapatite Nanoparticles–Ionic Liquids Based Composite Electrodes

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4344
Author(s):  
Merve Uca ◽  
Ece Eksin ◽  
Yasemin Erac ◽  
Arzum Erdem
Keyword(s):  
Electrochemical Impedance ◽  
Differential Pulse ◽  
Dna Interaction ◽  
Composite Electrodes ◽  
Hydroxyapatite Nanoparticles ◽  
Graphite Electrodes ◽  
X Ray ◽  
Pulse Voltammetry ◽  
Polymerase Chain

Hydroxyapatite nanoparticles (HaP) and ionic liquid (IL) modified pencil graphite electrodes (PGEs) are newly developed in this assay. Electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and cyclic voltammetry (CV) were applied to examine the microscopic and electrochemical characterization of HaP and IL-modified biosensors. The interaction of curcumin with nucleic acids and polymerase chain reaction (PCR) samples was investigated by measuring the changes at the oxidation signals of both curcumin and guanine by differential pulse voltammetry (DPV) technique. The optimization of curcumin concentration, DNA concentration, and the interaction time was performed. The interaction of curcumin with PCR samples was also investigated by gel electrophoresis.

scholarly journals A simple one-step electrochemical deposition of bioinspired nanocomposite for the non-enzymatic detection of dopamine

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vijayaraj Kathiresan ◽  
Dinakaran Thirumalai ◽  
Thenmozhi Rajarathinam ◽  
Miri Yeom ◽  
Jaewon Lee ◽  
...  
Keyword(s):  
Electrochemical Deposition ◽  
Electrochemical Impedance ◽  
High Surface ◽  
Electrochemical Characteristics ◽  
Surface Areas ◽  
Electrochemically Reduced Graphene Oxide ◽  
Sensitivity And Selectivity ◽  
Controlled Deposition ◽  
Enzymatic Detection ◽  
Walled Carbon Nanotubes

AbstractA simple and cost-effective electrochemical synthesis of carbon-based nanomaterials for electrochemical biosensor is of great challenge these days. Our study describes a single-step electrochemical deposition strategy to prepare a nanocomposite of electrochemically reduced graphene oxide (ErGO), multi-walled carbon nanotubes (MWCNTs), and polypyrrole (PPy) in an aqueous solution of pH 7.0 for dopamine (DA) detection. The ErGO/MWCNTs/PPy nanocomposites show enhanced electrochemical performance due to the strong π–π* stacking interactions among ErGO, MWCNTs, and PPy. The efficient interaction of the nanocomposites is confirmed by evaluating its physical and electrochemical characteristics using field-emission scanning electron microscopy, Raman spectroscopy, electrochemical impedance spectroscopy, cyclic voltammetry, and amperometry. The deposited nanocomposites are highly stable on the substrates and possess high surface areas, which is vital to improve the sensitivity and selectivity for DA detection. The controlled deposition of the ErGO/MWCNTs/PPy nanocomposites can provide enhanced electrochemical detection of DA. The sensor demonstrates a short time response within 2 s and is a highly sensitive approach for DA detection with a dynamic linear range of 25–1000 nM (R2 = 0.999). The detection limit is estimated to be 2.3 nM, and the sensor sensitivity is calculated to be 8.96 μA μM−1 cm−2, with no distinct responses observed for other biological molecules.

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