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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) DPASV response for a bare GC electrode (a) and for a EBB/PPy-modified electrode (b) after preconcentration in 10−5 M Ag+. The response of the electrode to 10−5 M Hg2+ is also shown in (c). Reprinted from [83] with permission from Elsevier; (B) DPASV of the solution containing Cd2+ (12.8 ppm) and Pb2+ (16.6 ppm) recorded at (a) a poly(diphenylamine-co-2-aminobenzonitrile)-modified electrode and (b) poly(diphenylamine)-modified electrode. Deposition potential = −1.0 V; deposition time = 60 s; pH = 2.1. Reprinted from [88] with permission from Elsevier.
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biosensors-05-00241-f007: (A) DPASV response for a bare GC electrode (a) and for a EBB/PPy-modified electrode (b) after preconcentration in 10−5 M Ag+. The response of the electrode to 10−5 M Hg2+ is also shown in (c). Reprinted from [83] with permission from Elsevier; (B) DPASV of the solution containing Cd2+ (12.8 ppm) and Pb2+ (16.6 ppm) recorded at (a) a poly(diphenylamine-co-2-aminobenzonitrile)-modified electrode and (b) poly(diphenylamine)-modified electrode. Deposition potential = −1.0 V; deposition time = 60 s; pH = 2.1. Reprinted from [88] with permission from Elsevier.

Mentions: The use of functional doping ions is probably the simplest way to functionalize CPs. For example, PPy membranes were deposited on GCE by electropolymerization of pyrrole in the presence of Eriochrome Blue-Black B (EBB) as counter anion [83]. The differential pulse anodic stripping voltammetry (DPASV) response of the EBB/PPy-modified electrode versus a bare GCE, both after preconcentration in 10−5 M Ag+ at −0.4 V for 200 s, is shown in Figure 7A; the sensor showed a LoD of ca. 6 × 10−9 M for Ag+. Following the same idea, Lisak et al. described a polybenzopyrene film into which Eriochrome black T was entrapped, able to form complexes with Pb2+ ion [84]. In another study, a polythiophene-quinoline (PTQ)-modified electrode was used to detect copper and mercury. The redox behaviors of Cu(II) and Hg(II) were almost identical on this electrode, but the addition of 4-(2-pyridylazo)resorcinol (PAR) allowed the separation of the two cations due to the formation of a Cu(II)-PAR complex reduced at −0.8 V, whereas that of Hg(II) appeared at −0.5 V vs. SCE. Hg(II) was detected down to 0.4 ppb [85].


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

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

(A) DPASV response for a bare GC electrode (a) and for a EBB/PPy-modified electrode (b) after preconcentration in 10−5 M Ag+. The response of the electrode to 10−5 M Hg2+ is also shown in (c). Reprinted from [83] with permission from Elsevier; (B) DPASV of the solution containing Cd2+ (12.8 ppm) and Pb2+ (16.6 ppm) recorded at (a) a poly(diphenylamine-co-2-aminobenzonitrile)-modified electrode and (b) poly(diphenylamine)-modified electrode. Deposition potential = −1.0 V; deposition time = 60 s; pH = 2.1. Reprinted from [88] with permission from Elsevier.
© Copyright Policy
Related In: Results  -  Collection

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

biosensors-05-00241-f007: (A) DPASV response for a bare GC electrode (a) and for a EBB/PPy-modified electrode (b) after preconcentration in 10−5 M Ag+. The response of the electrode to 10−5 M Hg2+ is also shown in (c). Reprinted from [83] with permission from Elsevier; (B) DPASV of the solution containing Cd2+ (12.8 ppm) and Pb2+ (16.6 ppm) recorded at (a) a poly(diphenylamine-co-2-aminobenzonitrile)-modified electrode and (b) poly(diphenylamine)-modified electrode. Deposition potential = −1.0 V; deposition time = 60 s; pH = 2.1. Reprinted from [88] with permission from Elsevier.
Mentions: The use of functional doping ions is probably the simplest way to functionalize CPs. For example, PPy membranes were deposited on GCE by electropolymerization of pyrrole in the presence of Eriochrome Blue-Black B (EBB) as counter anion [83]. The differential pulse anodic stripping voltammetry (DPASV) response of the EBB/PPy-modified electrode versus a bare GCE, both after preconcentration in 10−5 M Ag+ at −0.4 V for 200 s, is shown in Figure 7A; the sensor showed a LoD of ca. 6 × 10−9 M for Ag+. Following the same idea, Lisak et al. described a polybenzopyrene film into which Eriochrome black T was entrapped, able to form complexes with Pb2+ ion [84]. In another study, a polythiophene-quinoline (PTQ)-modified electrode was used to detect copper and mercury. The redox behaviors of Cu(II) and Hg(II) were almost identical on this electrode, but the addition of 4-(2-pyridylazo)resorcinol (PAR) allowed the separation of the two cations due to the formation of a Cu(II)-PAR complex reduced at −0.8 V, whereas that of Hg(II) appeared at −0.5 V vs. SCE. Hg(II) was detected down to 0.4 ppb [85].

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