the use is the high affinity for amalgam formation which leads to structural
changes over the surface of electrodes. The most common Screen printed Gold
electrodes (SPGEs) are commercially available for detection of Hg(II) [83].
Thiol based SPEs, PANi modified SPEs and PANi-Methylene Blue modified
SPEs are some of the modifiers used for electrochemical detections of Hg [78,
65, 85, 86, 87].
4. Arsenic: Arsenic detection is done by using PtNPs modified SPEs by electrochemically depositing K 2 PtCl 6 , citrate-capped AuNPs modified SPEs and AChE
modified SPCEs with no interferences from Cu(II) [69, 89, 90].
5. Mixture of metals: Bi modified SPEs can be used for simultaneous determination
of metal ions such as Pb(II), Zn(II) and Cd(II) [91]. Crown ether based SPEs on
thin film Hg electrodes are used for determination of Pb(II) and Cd(II) [92].
Chitosan, poly-[-1-4]-2-amino-2-deoxy-d-glucopyranose (CTS) forms stable
chelate complexes with many transition-metal ions through hydroxyl and amino
groups. CTS and their derivatives with Glassy carbon electrode (GCE) are used
for determination of metal ions [93]. Modified CTS-SPCEs are used for the
detection of Pb(II), Cu(II), Cd(II) and Hg(II) with very less preconcentration time
[94]. CTS-MWCNTs composite film showed noticeable improvements in
robustness of the electrode [95]. In-situ Hg deposited on MWCNTs-CHIT/SPE
was used for the simultaneous determination of Pb(II), Cd(II) and Cu(II) [96].
SPEs are proved to be effective method for the rapid detection of bacteria.
Enzyme-linked immunosensing strip was fabricated for the specific detection of
E. coli O157:H7 because of the use of double-specific antibodies [97]. Selective and
detection of E. coli was done based on an impedimetric immunosensor using SALs
modified gold SPEs in river and tap water samples without following preconcentration steps. Disposable SPEs were used for direct electron-transfer reaction at
Shewanella sp. bacteria without redox mediator [98]. Easy drop-coating of bacteria
was done to avoid tedious job and time-consuming step of growing a bacterial
bio-film formation on the surface of electrode.
Radionuclide such as Uranium determination was done using 4-carboxyphenylgrafted SPE has for sub-nanomolar U(VI) analysis using voltammetric methods
[99].
U(VI) detection in aqueous solutions was also done using electrochemically
induced, non-modified SPEs, with a detection limit of 4.5 nmol L
−1 [100].
Stripping-based electrochemical sensors
Heavy metal contamination is a serious matter of concern and is leading escalating
needs for monitoring these trace metals in environment especially water bodies.
Stripping analysis has been proved to be powerful technique for ascertaining toxic
metals in water samples [101, 102]. The ‘built-in’ preconcentration step adds to the
significant sensitivity of this method. Preconcentration requires the accumulation of
target metal ions on the surface of electrodes.
Electrolytic deposition for trace heavy metals and non-electrochemical preconcentration methods based on adsorptive accumulation of metal complexes have
Materials in Electrochemical Detection of Water Pollutants
173
changes over the surface of electrodes. The most common Screen printed Gold
electrodes (SPGEs) are commercially available for detection of Hg(II) [83].
Thiol based SPEs, PANi modified SPEs and PANi-Methylene Blue modified
SPEs are some of the modifiers used for electrochemical detections of Hg [78,
65, 85, 86, 87].
4. Arsenic: Arsenic detection is done by using PtNPs modified SPEs by electrochemically depositing K 2 PtCl 6 , citrate-capped AuNPs modified SPEs and AChE
modified SPCEs with no interferences from Cu(II) [69, 89, 90].
5. Mixture of metals: Bi modified SPEs can be used for simultaneous determination
of metal ions such as Pb(II), Zn(II) and Cd(II) [91]. Crown ether based SPEs on
thin film Hg electrodes are used for determination of Pb(II) and Cd(II) [92].
Chitosan, poly-[-1-4]-2-amino-2-deoxy-d-glucopyranose (CTS) forms stable
chelate complexes with many transition-metal ions through hydroxyl and amino
groups. CTS and their derivatives with Glassy carbon electrode (GCE) are used
for determination of metal ions [93]. Modified CTS-SPCEs are used for the
detection of Pb(II), Cu(II), Cd(II) and Hg(II) with very less preconcentration time
[94]. CTS-MWCNTs composite film showed noticeable improvements in
robustness of the electrode [95]. In-situ Hg deposited on MWCNTs-CHIT/SPE
was used for the simultaneous determination of Pb(II), Cd(II) and Cu(II) [96].
SPEs are proved to be effective method for the rapid detection of bacteria.
Enzyme-linked immunosensing strip was fabricated for the specific detection of
E. coli O157:H7 because of the use of double-specific antibodies [97]. Selective and
detection of E. coli was done based on an impedimetric immunosensor using SALs
modified gold SPEs in river and tap water samples without following preconcentration steps. Disposable SPEs were used for direct electron-transfer reaction at
Shewanella sp. bacteria without redox mediator [98]. Easy drop-coating of bacteria
was done to avoid tedious job and time-consuming step of growing a bacterial
bio-film formation on the surface of electrode.
Radionuclide such as Uranium determination was done using 4-carboxyphenylgrafted SPE has for sub-nanomolar U(VI) analysis using voltammetric methods
[99].
U(VI) detection in aqueous solutions was also done using electrochemically
induced, non-modified SPEs, with a detection limit of 4.5 nmol L
−1 [100].
Stripping-based electrochemical sensors
Heavy metal contamination is a serious matter of concern and is leading escalating
needs for monitoring these trace metals in environment especially water bodies.
Stripping analysis has been proved to be powerful technique for ascertaining toxic
metals in water samples [101, 102]. The ‘built-in’ preconcentration step adds to the
significant sensitivity of this method. Preconcentration requires the accumulation of
target metal ions on the surface of electrodes.
Electrolytic deposition for trace heavy metals and non-electrochemical preconcentration methods based on adsorptive accumulation of metal complexes have
Materials in Electrochemical Detection of Water Pollutants
173