Electrochemical Behaviour of Real-Time Sensor for Determination Mercury in Cosmetic Products Based on PANI/MWCNTs/AuNPs/ITO

Mercury is a common ingredient found in skin lightening soaps, creams, and makeup-cleansing products. It may cause skin rashes, skin discolouration, and scarring, as well as a reduction in the skin’s resistance to bacterial and fungal infections. By looking at this scenario, developing a sensor that involved a simple procedure and fasts for real-time detection without affecting mercury sensitivity is urgently needed. For that reason, a fast and sensitive electrochemical method was developed to determine mercury in cosmetic products with the composition of polyaniline/multi-walled carbon nanotubes/gold nanoparticles/indium tin oxide sheet using methylene blue as a redox indicator. The significantly enhanced electrochemical performance was observed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). In order to detect mercury qualitatively and quantitatively, deposition potential and deposition time were respectively optimised to be 0.10 V and 70 s. The modified sensor was revealed a wide detection range of mercury from 0.01 to 10.00 ppm with a limit of detection of 0.08 ppm. The modified sensor towards mercury with a correlation coefficient (r2) was of 0.9948. Multiple cycling, reproducibility, and consistency of different modified sensors were investigated to verify the modified sensor’s performance. The developed sensing platform was highly selective toward mercury among the pool of possible interferents, and the stability of the developed sensor was ensured for at least 21 days after 10 repeated uses. The proposed method is a fast and simple procedure technique for analysing the mercury levels in cosmetic products.

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Interaction between Amorphous Zirconia Nanoparticles and Graphite: Electrochemical Applications for Gallic Acid Sensing Using Carbon Paste Electrodes in Wine

Nanomaterials ◽

10.3390/nano10030537 ◽

2020 ◽

Vol 10 (3) ◽

pp. 537 ◽

Cited By ~ 3

Author(s):

Chrys. O. Chikere ◽

Nadimul Haque Faisal ◽

Paul Kong-Thoo-Lin ◽

Carlos Fernandez

Keyword(s):

Gallic Acid ◽

Limit Of Detection ◽

Electrochemical Behaviour ◽

Differential Pulse ◽

White Wine ◽

Zro2 Nanoparticles ◽

Carbon Paste ◽

X Ray ◽

Zirconia Nanoparticles

Amorphous zirconium oxide nanoparticles (ZrO2) have been used for the first time, to modify carbon paste electrode (CPE) and used as a sensor for the electrochemical determination of gallic acid (GA). The voltammetric results of the ZrO2 nanoparticles-modified CPE showed efficient electrochemical oxidation of gallic acid, with a significantly enhanced peak current from 261 µA ± 3 to about 451 µA ± 1. The modified surface of the electrode and the synthesised zirconia nanoparticles were characterised by scanning electrode microscopy (SEM), Energy-dispersive x-ray spectroscopy (EDXA), X-ray powdered diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). Meanwhile, the electrochemical behaviour of GA on the surface of the modified electrode was studied using differential pulse voltammetry (DPV), showing a sensitivity of the electrode for GA determination, within a concentration range of 1 × 10−6 mol L−1 to 1 × 10−3 mol L−1 with a correlation coefficient of R2 of 0.9945 and a limit of detection of 1.24 × 10−7 mol L−1 (S/N = 3). The proposed ZrO2 nanoparticles modified CPE was successfully used for the determination of GA in red and white wine, with concentrations of 0.103 mmol L−1 and 0.049 mmol L−1 respectively.

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Triplex Real-Time PCR without DNA Extraction for the Monitoring of Meningococcal Disease

Diagnostics ◽

10.3390/diagnostics8030058 ◽

2018 ◽

Vol 8 (3) ◽

pp. 58 ◽

Cited By ~ 1

Author(s):

Melissa Whaley ◽

Laurel Jenkins ◽

Fang Hu ◽

Alexander Chen ◽

Seydou Diarra ◽

...

Keyword(s):

Cerebrospinal Fluid ◽

Real Time ◽

Dna Extraction ◽

Sensitivity And Specificity ◽

Real Time Pcr ◽

Limit Of Detection ◽

Detection Range ◽

Clinical Specimens ◽

Large Numbers ◽

Pcr Assays

Detection of Neisseria meningitidis has become less time- and resource-intensive with a monoplex direct real-time PCR (drt-PCR) to amplify genes from clinical specimens without DNA extraction. To further improve efficiency, we evaluated two triplex drt-PCR assays for the detection of meningococcal serogroups AWX and BCY. The sensitivity and specificity of the triplex assays were assessed using 228 cerebrospinal fluid (CSF) specimens from meningitis patients and compared to the monoplex for six serogroups. The lower limit of detection range for six serogroup-specific drt-PCR assays was 178–5264 CFU/mL by monoplex and 68–2221 CFU/mL by triplex. The triplex and monoplex showed 100% agreement for six serogroups and the triplex assays achieved similar sensitivity and specificity estimates as the monoplex drt-PCR assays. Our triplex method reduces the time and cost of processing CSF specimens by characterizing six serogroups with only two assays, which is particularly important for testing large numbers of specimens for N. meningitidis surveillance.

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Sensitive Determination of Epinephrine in the Presence of Ascorbic Acid at Poly(diphenylamine sulfonic acid) Modified Sensor

Sensor Letters ◽

10.1166/sl.2020.4228 ◽

2020 ◽

Vol 18 (4) ◽

pp. 253-258

Author(s):

Gamze Erdoğdu

Keyword(s):

Ascorbic Acid ◽

Sulfonic Acid ◽

Limit Of Detection ◽

Phosphate Buffer Solution ◽

Differential Pulse ◽

Buffer Solution ◽

Sensitive Determination ◽

Pulse Voltammetry ◽

Modified Sensor

A sensitive and simple modified sensor was prepared by electrodeposition of diphenylamine sulfonic acid (DPSA) to the glassy carbon electrode surface by cyclic voltammetry (CV) technique. The electrooxidation of epinephrine (EP) was accomplished by CV and differential pulse voltammetry at poly(DPSA) modified sensor. As a result of the findings, the current values were enhanced and both substances were separated at the modified sensor compared to the bare electrode. There was linearly between the oxidation current and concentration of EP from 0.2 to 100 μM in phosphate buffer solution at pH 7.0. The limit of detection was 5.0 nM and the sensitivity was 0.4205 μA/μM. The determination of EP was successfully and satisfactorily carried out in real samples such as human blood serum and urine at the poly(DPSA) sensor. To the best knowledge of this work, this is the first study that detect the EP in the presence of ascorbic acid at poly(DPSA) sensor in the literature.

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Magnetically induced self-assembly DNAzyme electrochemical biosensor based on gold-modified α-Fe2O3/Fe3O4 heterogeneous nanoparticles for sensitive detection of Ni2+

Nanotechnology ◽

10.1088/1361-6528/ac3b0e ◽

2021 ◽

Author(s):

Lulu Yu ◽

Min Liu ◽

Yanling Zhang ◽

Yun Ni ◽

Shaobo Wu ◽

...

Keyword(s):

Self Assembly ◽

Electrochemical Biosensor ◽

Limit Of Detection ◽

Sol Gel ◽

Trisodium Citrate ◽

Thiol Group ◽

Differential Pulse ◽

Electrochemical Sensing ◽

Detection Range ◽

Sensing Platform

Abstract A magnetically induced self-assembly DNAzyme electrochemical biosensor based on gold-modified α-Fe2O3/Fe3O4 heterogeneous nanoparticles was successfully fabricated to detect Nickel(II) (Ni2+). The phase composition and magnetic properties of α-Fe2O3/Fe3O4 heterogeneous nanoparticles controllably prepared by the citric acid (CA) sol-gel method were investigated in detail. The α-Fe2O3/Fe3O4 heterogeneous nanoparticles were modified by using trisodium citrate as reducing agent, and the magnetically induced self-assembly α-Fe2O3/Fe3O4-Au nanocomposites were obtained. The designed Ni2+-dependent DNAzyme consisted of the catalytic chain modified with the thiol group (S1-SH) and the substrate chain modified with methylene blue (S2-MB). The MGCE/α-Fe2O3/Fe3O4-Au/S1/BSA/S2 electrochemical sensing platform was constructed and differential pulse voltammetry (DPV) was applied for electrochemical detection. Under the optimum experimental parameters, the detection range of the biosensor was 100 pM-10 µM (R2= 0.9978) with the limit of detection (LOD) of 55 pM. The biosensor had high selectivity, acceptable stability, and reproducibility (RSD = 4.03%).

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Electrochemical Sensor for Acetaminophen Based on a Poly(diphenylamine sulfonic acid) Modified Sensor

Sensor Letters ◽

10.1166/sl.2020.4285 ◽

2020 ◽

Vol 18 (10) ◽

pp. 739-744

Author(s):

Gamze Erdogdu

Keyword(s):

Sulfonic Acid ◽

Limit Of Detection ◽

Differential Pulse ◽

Carbon Electrode ◽

Buffer Solution ◽

Real Samples ◽

Oxidation Current ◽

Pulse Voltammetry ◽

Modified Sensor

A sensitive and simple modified sensor was prepared by electrodeposition of diphenylamine sulfonic acid (DPSA) to the glassy carbon electrode surface by cyclic voltammetry (CV) technique. The electrooxidation of Acetaminophen (AC) was accomplished by CV and differential pulse voltammetry at poly(DPSA) modified sensor. As a result of the findings, the current values were enhanced and both substances were separated at the modified sensor compared to the bare electrode. There was linearly between the oxidation current and concentration of AC from 0.0 to 100 μM in phospate buffer solution at pH 7.0. The limit of detection was 3.0 nM and the sensitivity was 0.4108 μA/μM. The determination of AC was successfully and satisfactorily carried out in real samples such as human blood serum and urine at the poly(DPSA) sensor. To the best knowledge of this work, this is the first study that detect the AC in the presence of ascorbic acid at poly(DPSA) sensor in the literature.

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Comparative Studies of CPEs Modified with Distinctive Metal Nanoparticle-Decorated Electroactive Polyimide for the Detection of UA

Polymers ◽

10.3390/polym13020252 ◽

2021 ◽

Vol 13 (2) ◽

pp. 252

Author(s):

Aamna Bibi ◽

Sheng-Chieh Hsu ◽

Wei-Fu Ji ◽

Yi-Chi Cho ◽

Karen S. Santiago ◽

...

Keyword(s):

Limit Of Detection ◽

Initial Step ◽

Differential Pulse ◽

Metal Nanoparticle ◽

Carbon Paste ◽

Detection Range ◽

Au Nps ◽

Linear Detection ◽

Paste Electrode

In this present work, an electrochemical sensor was developed for the sensing of uric acid (UA). The sensor was based on a carbon paste electrode (CPE) modified with electroactive polyimide (EPI) synthesized using aniline tetramer (ACAT) decorated with reduced nanoparticles (NPs) of Au, Pt, and Ag. The initial step involved the preparation and characterization of ACAT. Subsequently, the ACAT-based EPI synthesis was performed by chemical imidization of its precursors 4,4′-(4.4′-isopropylidene-diphenoxy) bis (phthalic anhydride) BPADA and ACAT. Then, EPI was doped with distinctive particles of Ag, Pt and Au, and the doped EPIs were abbreviated as EPIS, EPIP and EPIG, respectively. Their structures were characterized by XRD, XPS, and TEM, and the electrochemical properties were determined by cyclic voltammetry and chronoamperometry. Among these evaluated sensors, EPI with Au NPs turned out the best with a sensitivity of 1.53 uA uM−1 UA, a low limit of detection (LOD) of 0.78 uM, and a linear detection range (LDR) of 5–50 uM UA at a low potential value of 310 mV. Additionally, differential pulse voltammetric (DPV) analysis showed that the EPIG sensor showed the best selectivity for a tertiary mixture of UA, dopamine (DA), and ascorbic acid (AA) as compared to EPIP and EPIS.

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Electrochemical Determination of Norepinephrine at Poly (p-aminobenzenesulfonic Acid) Modified Sensor

Current Pharmaceutical Analysis ◽

10.2174/1573412915666190212160442 ◽

2020 ◽

Vol 16 (5) ◽

pp. 591-600

Author(s):

Şevket Zişan Yağcı ◽

Ebru Kuyumcu Savan ◽

Gamze Erdoğdu

Keyword(s):

Ascorbic Acid ◽

Limit Of Detection ◽

Phosphate Buffer Solution ◽

Differential Pulse ◽

Electrochemical Determination ◽

Buffer Solution ◽

Oxidation Current ◽

Pulse Voltammetry ◽

Modified Sensor

Objective: In this study, it was aimed to prepare an electrochemical sensor capable of assigning Norepinephrine in the presence of an interference such as ascorbic acid. Methods: A sensitive modified sensor was prepared by electrodeposition of p-aminobenzenesulfonic acid (p-ABSA) to the glassy carbon electrode by cyclic voltammetry. The electrooxidation of Norepinephrine was accomplished by cyclic and differential pulse voltammetry. Results: The current values were enhanced and the peak potentials of Norepinephrine and ascorbic acid were separated at the sensor compared to the bare electrode. There was linearity between the oxidation current and concentration of Norepinephrine ranging from 0.5 to 99.8 μM in phosphate buffer solution at pH 7.0. The limit of detection was 10.0 nM and the sensitivity was 0.455 μA/μM. Conclusion: The determination of Norepinephrine was successfully performed in real samples such as blood serum and urine at the poly (p-ABSA) sensor. To the best of our knowledge, this is the first study to detect Norepinephrine in the presence of ascorbic acid at poly (p-ABSA) modified sensor in the literature.

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Electrochemical Behaviour of 3-Pyridyl-N,N-bis[(8-quinolyl)amino]methane

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19931279 ◽

1993 ◽

Vol 58 (6) ◽

pp. 1279-1284

Author(s):

Angeles Loeches ◽

Carmen Teijeiro ◽

Dolores Marín

Keyword(s):

Cyclic Voltammetry ◽

Limit Of Detection ◽

Electrochemical Behaviour ◽

Differential Pulse ◽

Differential Pulse Polarography ◽

Reduction Mechanism ◽

Pulse Polarography ◽

Dc Polarography ◽

The Waves

3-Pyridyl-N,N-bis[(8-quinolyl)amino]methane was studied by DC polarography, coulometry, cyclic voltammetry and differential pulse polarography in a system comprising Britton-Robinson buffer and 15 vol.% ethanol at pH 7.0. The nature of the waves was investigated, and the reduction mechanism is suggested. DPP was also used for a quantitative determination of the substance, and a limit of detection of 3 μmol l-1 was obtained.

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Electrochemical Study of Diphenyl Ether Derivatives Used as Herbicides

International Journal of Electrochemistry ◽

10.4061/2011/904570 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6 ◽

Cited By ~ 6

Author(s):

Amira Zaouak ◽

Fatma Matoussi ◽

Mohamed Dachraoui

Keyword(s):

Limit Of Detection ◽

Electrochemical Behaviour ◽

Diphenyl Ether ◽

Differential Pulse ◽

Compound A ◽

Selective Determination ◽

Diphenyl Ethers ◽

Pulse Voltammetry ◽

Major Oxidation

The electrochemical behaviour of five nitro diphenyl ethers used as herbicides is investigated in acetonitrile. A detailed study by cyclic voltammetry and exhaustive electrolysis is carried out for the anodic oxidation of 2-Chloro-6-nitro-3-phenoxyaniline (aclonifen) and shows that the major oxidation product is a dimeric compound. A mechanistic scheme involving a coupling process is postulated for the electrochemical oxidation of this compound. Furthermore, the use of differential pulse voltammetry on a glassy carbon electrode permits the selective determination ofaclonifen. The limit of detection is 0.6 μg/mL.

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The Alternative Voltammetric Method for the Determination of Nicotine and Its Metabolite Nicotine N-Oxide

Journal of The Electrochemical Society ◽

10.1149/1945-7111/ac4b26 ◽

2022 ◽

Author(s):

Olha Dushna ◽

Liliya Dubenska ◽

Serhiy Plotycya ◽

Mariana Rydchuk ◽

Mykola Blazheyevskіy

Keyword(s):

Limit Of Detection ◽

Biological Fluids ◽

Electrochemical Behaviour ◽

Pharmaceutical Preparations ◽

Linear Sweep Voltammetry ◽

Differential Pulse ◽

Analytical Form ◽

Silver Solid Amalgam Electrode ◽

Drugs Analysis ◽

First Time

Abstract In the present paper, for the first time, the electrochemical behaviour of nicotine metabolite nicotine N-oxide (NNO) on static mercury dropping electrode (SMDE) and mercury meniscus modified silver solid amalgam electrode (m-AgSAE) has been reported. Nicotine N-oxide is reduced forming one peak at the potential -0.78 V on SDME and -0.86 V on m-AgSAE in Britton-Robinson buffer medium at pH 4.5 using cyclic voltammetry (CV). One electron and one proton take part in the reaction of NNO reduction. Calibration graphs for NNO determination using linear sweep voltammetry (LSV) on SDME and square-wave voltammetry (SWV) and differential pulse voltammetry (DPV) on m-AgSAE were obtained. Limit of detection (LOD) is 0.13 μM on SDME, and 0.16 μM (SWV) and 0.29 μM (DPV) on m-AgSAE. Since NNO can be used as an analytical form for nicotine voltammetric determination, so the developed methods were applied for the analysis of pharmaceutical preparations, and the recoveries from 97.3 to 104.6 % were achieved. Also, the elaborated methods were used in the analysis of biological fluids, and tobacco products. The obtained results were compared to those indicated in the certificates of drugs analysis, and to the results, obtained by reference methods (HPLC and GC).

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