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Modified electrodes used for electrochemical detection of metal ions in environmental analysis.

March G, Nguyen TD, Piro B - Biosensors (Basel) (2015)

Bottom Line: Many efforts have been made to develop sensors for monitoring heavy metals in the environment.The first part of this review will be dedicated to stripping voltammetry techniques, on unmodified electrodes (mercury, bismuth or noble metals in the bulk form), or electrodes modified at their surface by nanoparticles, nanostructures (CNT, graphene) or other innovative materials such as boron-doped diamond.Special attention will be paid to strategies using biomolecules (DNA, peptide or proteins), enzymes or whole cells.

View Article: PubMed Central - PubMed

Affiliation: Klearia, route de Nozay, Marcoussis 91460, France. gregory.march@free.fr.

ABSTRACT
Heavy metal pollution is one of the most serious environmental problems, and regulations are becoming stricter. Many efforts have been made to develop sensors for monitoring heavy metals in the environment. This review aims at presenting the different label-free strategies used to develop electrochemical sensors for the detection of heavy metals such as lead, cadmium, mercury, arsenic etc. The first part of this review will be dedicated to stripping voltammetry techniques, on unmodified electrodes (mercury, bismuth or noble metals in the bulk form), or electrodes modified at their surface by nanoparticles, nanostructures (CNT, graphene) or other innovative materials such as boron-doped diamond. The second part will be dedicated to chemically modified electrodes especially those with conducting polymers. The last part of this review will focus on bio-modified electrodes. Special attention will be paid to strategies using biomolecules (DNA, peptide or proteins), enzymes or whole cells.

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(A) CVs of HeLa cell suspension (2.0 × 105 cells·mL−1) treated during 30 h with 20 μM of heavy metals solutions. (a) no HM, (b) Zn2+, (c) Pb2+, (d) Cu2+, (e) Cd2+, (f) Cr6+; (B) Peak currents obtained after exposure to different concentrations of Cr6+. Reprinted from [135] with permission from Elsevier.
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biosensors-05-00241-f019: (A) CVs of HeLa cell suspension (2.0 × 105 cells·mL−1) treated during 30 h with 20 μM of heavy metals solutions. (a) no HM, (b) Zn2+, (c) Pb2+, (d) Cu2+, (e) Cd2+, (f) Cr6+; (B) Peak currents obtained after exposure to different concentrations of Cr6+. Reprinted from [135] with permission from Elsevier.

Mentions: Adam et al. [134] have described an electrochemical method for studying the behavior of Escherichia coli that is modified in order to express the human metallothionein gene (MT-3). MT-3 is a cysteine-rich protein known to bind metal ions; after exposure of the bacteria to heavy metal ions, metallothionein was isolated using fast protein liquid chromatography and quantified by electrochemical methods (through typical cysteine oxidation). Its interactions with cadmium and lead ions showed a decline in electrochemistry due to metal ions binding to cysteine. Zhu et al. [135] reported a label-free electrochemical method based on the direct voltammetric response of human cervical carcinoma (HeLa) cells on a reduced graphene oxide-modified glassy carbon electrode. Five heavy metals were tested (Cr, Cd, Cu, Pb, Zn) with an excellent correlation using a traditional quantification assay. Actually, the method is cell counting, which is based on the quantity of guanine and xanthine secreted in the cell suspension and oxidized on the electrode, yielding an anodic potential of around +0.67 V vs. Ag/AgCl (Figure 19).


Modified electrodes used for electrochemical detection of metal ions in environmental analysis.

March G, Nguyen TD, Piro B - Biosensors (Basel) (2015)

(A) CVs of HeLa cell suspension (2.0 × 105 cells·mL−1) treated during 30 h with 20 μM of heavy metals solutions. (a) no HM, (b) Zn2+, (c) Pb2+, (d) Cu2+, (e) Cd2+, (f) Cr6+; (B) Peak currents obtained after exposure to different concentrations of Cr6+. Reprinted from [135] with permission from Elsevier.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493548&req=5

biosensors-05-00241-f019: (A) CVs of HeLa cell suspension (2.0 × 105 cells·mL−1) treated during 30 h with 20 μM of heavy metals solutions. (a) no HM, (b) Zn2+, (c) Pb2+, (d) Cu2+, (e) Cd2+, (f) Cr6+; (B) Peak currents obtained after exposure to different concentrations of Cr6+. Reprinted from [135] with permission from Elsevier.
Mentions: Adam et al. [134] have described an electrochemical method for studying the behavior of Escherichia coli that is modified in order to express the human metallothionein gene (MT-3). MT-3 is a cysteine-rich protein known to bind metal ions; after exposure of the bacteria to heavy metal ions, metallothionein was isolated using fast protein liquid chromatography and quantified by electrochemical methods (through typical cysteine oxidation). Its interactions with cadmium and lead ions showed a decline in electrochemistry due to metal ions binding to cysteine. Zhu et al. [135] reported a label-free electrochemical method based on the direct voltammetric response of human cervical carcinoma (HeLa) cells on a reduced graphene oxide-modified glassy carbon electrode. Five heavy metals were tested (Cr, Cd, Cu, Pb, Zn) with an excellent correlation using a traditional quantification assay. Actually, the method is cell counting, which is based on the quantity of guanine and xanthine secreted in the cell suspension and oxidized on the electrode, yielding an anodic potential of around +0.67 V vs. Ag/AgCl (Figure 19).

Bottom Line: Many efforts have been made to develop sensors for monitoring heavy metals in the environment.The first part of this review will be dedicated to stripping voltammetry techniques, on unmodified electrodes (mercury, bismuth or noble metals in the bulk form), or electrodes modified at their surface by nanoparticles, nanostructures (CNT, graphene) or other innovative materials such as boron-doped diamond.Special attention will be paid to strategies using biomolecules (DNA, peptide or proteins), enzymes or whole cells.

View Article: PubMed Central - PubMed

Affiliation: Klearia, route de Nozay, Marcoussis 91460, France. gregory.march@free.fr.

ABSTRACT
Heavy metal pollution is one of the most serious environmental problems, and regulations are becoming stricter. Many efforts have been made to develop sensors for monitoring heavy metals in the environment. This review aims at presenting the different label-free strategies used to develop electrochemical sensors for the detection of heavy metals such as lead, cadmium, mercury, arsenic etc. The first part of this review will be dedicated to stripping voltammetry techniques, on unmodified electrodes (mercury, bismuth or noble metals in the bulk form), or electrodes modified at their surface by nanoparticles, nanostructures (CNT, graphene) or other innovative materials such as boron-doped diamond. The second part will be dedicated to chemically modified electrodes especially those with conducting polymers. The last part of this review will focus on bio-modified electrodes. Special attention will be paid to strategies using biomolecules (DNA, peptide or proteins), enzymes or whole cells.

Show MeSH
Related in: MedlinePlus