scholarly journals Polyazulene-Based Materials for Heavy Metal Ion Detection. 3. (E)-5-((6-t-Butyl-4,8-dimethylazulen-1-yl) diazenyl)-1H-tetrazole-Based Modified Electrodes

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1642
Author(s):  
Laura-Bianca Enache ◽  
Veronica Anăstăsoaie ◽  
Cecilia Lete ◽  
Alina Giorgiana Brotea ◽  
Ovidiu-Teodor Matica ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ion ◽  
Electrochemical Sensors ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Free Ligand ◽  
Modified Electrodes ◽  
Differential Pulse ◽  
Rotating Disk Electrode ◽  
Ion Detection

A recently synthesized azulene-tetrazole molecular receptor is proposed in this paper to continue the series of azulene substituted compounds that have been developed to build polyazulene-based materials for heavy metal (HM) ion detection. This study focuses on characterization of (E)-5-((6-t-butyl-4,8-dimethylazulen-1-yl) diazenyl)-1H-tetrazole (L) by electrochemical techniques in view of its use for designing electrochemical sensors for HM ion complexation. The character of redox processes was proved by cyclic, differential pulse, and rotating disk electrode voltammetry. An in-depth thermodynamic study of the complexation properties of the free ligand with Pb(II) and Cd(II) from aqueous solutions was performed, and the stoichiometry and stability constant values were determined. Chemically modified electrodes (CMEs) based on L (L-CMEs) prepared by controlled potential electrolysis (CPE) at different applied potentials and charges were characterized by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). Their surface morphology was examined by scanning electron microscopy (SEM). The complexing properties of L-CMEs were investigated towards the detection of HM ions by anodic stripping and compared to the stability constants of the complexes in solution. Voltametric curves showed well-defined peaks for Pb (II), Cd (II), Cu (II) and Hg (II), but the responses differ from each other and vary depending on the ion concentrations in the accumulation solutions. The best results were obtained for Pb(II) and Cd(II) ions. The results obtained for Pb(II) are promising and can be used for its analysis in water solutions (detection limit of about 10−9 M).

scholarly journals Polyazulene-Based Materials for Heavy Metal Ion Detection. 2. (E)-5-(azulen-1-yldiazenyl)-1H-Tetrazole-Modified Electrodes for Heavy Metal Sensing

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 869
Author(s):  
Laura-Bianca Enache ◽  
Veronica Anăstăsoaie ◽  
Liviu Birzan ◽  
Eleonora-Mihaela Ungureanu ◽  
Peng Diao ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ion ◽  
Electrochemical Techniques ◽  
Modified Electrodes ◽  
Advanced Materials ◽  
Heavy Metal Ion ◽  
Ion Sensing ◽  
Controlled Potential ◽  
Metal Ion Detection ◽  
Heavy Metal Sensing

Azulene-based materials present very appealing properties for the preparation of advanced materials. They can be irreversibly electrooxidated, leading to polymers, which can be deposited on electrodes and modified. This paper shows several experiments concerning the preparation of modified electrodes based on (E)-5-(azulen-1-yldiazenyl)-1H-tetrazole (L). L has a tetrazole complexing unit, which can be attached to the electrode’s surface and recognized. L has been deeply characterized by electrochemical techniques. Complexing modified electrodes have been prepared and tested in different conditions. Functional modified electrodes based on L obtained by controlled potential electrolysis were examined by AFM and SEM to see the influences of charge and potential on the deposited polyz films’ morphologies. The modified electrodes prepared in different conditions have been tested for heavy metal ion sensing. The new azulene-based modified electrode demonstrated its feasibility for Pb ions analysis (detection limit of 5 × 10−8 M, and linear domain between 5 × 10−8 M and 10−6 M) and potential use in future applications for real water samples analysis.

scholarly journals Surface Characterization of New Azulene-Based CMEs for Sensing

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2292
Author(s):  
Veronica Anăstăsoaie ◽  
Cristian Omocea ◽  
Laura-Bianca Enache ◽  
Liana Anicăi ◽  
Eleonora-Mihaela Ungureanu ◽  
...  
Keyword(s):  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Film Formation ◽  
Modified Electrodes ◽  
Rotating Disk ◽  
Differential Pulse ◽  
Rotating Disk Electrode ◽  
Irreversible Processes ◽  
Rotating Disk Electrode Voltammetry

Films of 2-(azulen-1-yldiazenyl)-5-phenyl-1,3,4-thiadiazole (T) were successfully deposited on glassy carbon surfaces to prepare chemically modified electrodes (CMEs). Their surface characterization was analyzed by electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM), and scanning electron microscopy (SEM). This complexing monomer has been deposited through direct electropolymerization in conditions established during the electrochemical characterization of T performed by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and rotating disk electrode voltammetry (RDE). These methods put in evidence the high degree of asymmetry of oxidation and reduction curves, which is due to the irreversible processes occurring at opposite potentials. The film formation was confirmed by ferrocene redox assay probe. The properties of the electrodes modified with T (T-CMEs) were investigated for sensing heavy metal (HM) ions in water solutions, with promising results for Pb(II) among Cd(II), Cu(II), and Hg(II) ions.

scholarly journals Recognition of Heavy Metal Ions by Using E-5-((5-Isopropyl-3,8-Dimethylazulen-1-yl) Dyazenyl)-1H-Tetrazole Modified Electrodes

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 644
Author(s):  
Adina-Maria Păun ◽  
Ovidiu-Teodor Matica ◽  
Veronica Anăstăsoaie ◽  
Laura-Bianca Enache ◽  
Elena Diacu ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Film Formation ◽  
Modified Electrodes ◽  
Rotating Disk ◽  
Differential Pulse ◽  
Rotating Disk Electrode ◽  
Polymeric Films ◽  
Rotating Disk Electrode Voltammetry

Chemically modified electrodes (CMEs) based on polymeric films of E-5-((5-isopropyl-3,8-dimethylazulen-1-yl) diazenyl)-1H-tetrazole (L) deposited on the surface of the glassy carbon electrode have been used for the recognition of heavy metal (Me) ions. The electrochemical study of L was done by three methods: differential pulse voltammetry (DPV), cyclic voltammetry (CV), and rotating disk electrode voltammetry (RDE). The CV, DPV, and RDE studies for L were performed at different concentrations in 0.1 M tetrabutylammonium perchlorate solutions in acetonitrile. The polymeric films were formed by successive cycling or by controlled potential electrolysis (CPE). The film formation was proven by recording the CV curves of the CMEs in ferrocene solution. The CMEs prepared at different charges or potentials were used for detection of heavy metal ions. Synthetic samples of heavy metal ions (Cd(II), Pb(II), Cu(II), Hg(II)) of concentrations between 10−8 and 10−4 M were analyzed. The most intense signal was obtained for Pb(II) ion (detection limit of about 10−8 M). Pb(II) ion can be detected by these CMEs in waters at such concentrations. The ability of the ligand L to form complexes with Pb(II) and Hg(II) ions was also tested by UV-Vis spectrometry. The obtained results showed the formation of Me(II)L2 complexes.

Sensitive, portable heavy-metal-ion detection by the sulfidation method on a superhydrophobic concentrator (SPOT)

One Earth ◽  
2021 ◽  
Author(s):  
Hiang Kwee Lee ◽  
Wenxiao Huang ◽  
Yusheng Ye ◽  
Jinwei Xu ◽  
Yucan Peng ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ion ◽  
Heavy Metal Ion ◽  
Ion Detection ◽  
Metal Ion Detection

Structurally Colored Thiol Chitosan Thin Films as a Platform for Aqueous Heavy Metal Ion Detection

2008 ◽  
Vol 9 (1) ◽  
pp. 289-295 ◽  
Author(s):  
Matthew D. Cathell ◽  
Janah C. Szewczyk ◽  
Frances A. Bui ◽  
Carrie A. Weber ◽  
Jessica D. Wolever ◽  
...  
Keyword(s):  
Thin Films ◽  
Heavy Metal ◽  
Metal Ion ◽  
Heavy Metal Ion ◽  
Ion Detection ◽  
Metal Ion Detection

scholarly journals Correction: Electrochemical microfluidics techniques for heavy metal ion detection

The Analyst ◽  
2018 ◽  
Vol 143 (23) ◽  
pp. 5857-5857 ◽  
Author(s):  
Su Li ◽  
Chencheng Zhang ◽  
Shengnan Wang ◽  
Qing Liu ◽  
Huanhuan Feng ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ion ◽  
Heavy Metal Ion ◽  
Ion Detection ◽  
Metal Ion Detection

Correction for ‘Electrochemical microfluidics techniques for heavy metal ion detection’ by Su Li et al., Analyst, 2018, 143, 4230–4246.

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.

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