monitored visually. The standard deviation and LOD were calculated as 3.21% and
250 nM (S/N = 3). Thus, GQDs-OPD platform was established as a dual sensor for
the detection of Ag
+
.
4 Electrochemical Technique for Detection of Toxic Water
Pollutants
The electrochemical sensing method is highly selective as well as a sensitive
technique for the determination of non-UV-absorbing analytes. Nevertheless, the
electrochemical sensor also potentially worked on the determination of
UV-absorbing analytes. It is an easy detection technique for the simultaneous
detection of single as well as multiple water pollutants. This is a very powerful
sensing technique, which can detect electric current, generated from either oxidation or reduction reactions in the test mixtures. In this method, the sensing takes
place on a cell containing a working electrode and existing a counter electrode
which maintaining stable potential [53, 54]. The electrochemical sensor is classified
as potentiometric, conductometric, and amperometric based on the property of the
acquired sensor. The recognition element and physical transducer (electrode) is
present in all kind of sensors. The sensor performance is fully depending on the
interaction between the electrolytes of the test samples and the electrode surface
[55]. The large surface and small size materials electrodes have high sensitivity
towards the detection of target molecules [56].
Nanomaterials with high surface to volume ratio employed as highly selective as
well as sensitive electrochemical sensors for the detection of different organic and
inorganic pollutants materials [57]. Plasmonic nanoparticles such as Au, Ag, Cu
have shape and size dependent optoelectric properties; these are widely utilized as
sensing materials for environmental applications [58]. Plasmonic nanoparticles
have promising approaches as electrochemical sensors, due to the high stability;
these are produced the robust potential for on-site detection of water pollutants [59,
60]. Generally, carbon-based nanomaterials are widely used in electrochemical
applications due to their low cost, high chemical stability, and electrocatalytic
activity for the different redox reactions [61, 62]. Among the carbonaceous materials, graphene-based nanomaterials have wonderful potential for electrochemical
application as unique electrode materials, which have enhanced electron transfer
rate, high signal to noise ratio, and they increased the mass transfer rate [63]. The
hydroxyl and carboxyl group present in the graphene surface may interact with
organic pollutants molecules, and form complexes with pollutant metal ions result
in high sensing activity of the graphene-based composite materials [64, 65].
Graphene-based electrochemical sensors have the ability to detect individual ions as
well as multiple metal ions up to a low detection limit and which can detect metal
ion concentration deviation in the groundwater sample.
92
M. J. Deka et al.
250 nM (S/N = 3). Thus, GQDs-OPD platform was established as a dual sensor for
the detection of Ag
+
.
4 Electrochemical Technique for Detection of Toxic Water
Pollutants
The electrochemical sensing method is highly selective as well as a sensitive
technique for the determination of non-UV-absorbing analytes. Nevertheless, the
electrochemical sensor also potentially worked on the determination of
UV-absorbing analytes. It is an easy detection technique for the simultaneous
detection of single as well as multiple water pollutants. This is a very powerful
sensing technique, which can detect electric current, generated from either oxidation or reduction reactions in the test mixtures. In this method, the sensing takes
place on a cell containing a working electrode and existing a counter electrode
which maintaining stable potential [53, 54]. The electrochemical sensor is classified
as potentiometric, conductometric, and amperometric based on the property of the
acquired sensor. The recognition element and physical transducer (electrode) is
present in all kind of sensors. The sensor performance is fully depending on the
interaction between the electrolytes of the test samples and the electrode surface
[55]. The large surface and small size materials electrodes have high sensitivity
towards the detection of target molecules [56].
Nanomaterials with high surface to volume ratio employed as highly selective as
well as sensitive electrochemical sensors for the detection of different organic and
inorganic pollutants materials [57]. Plasmonic nanoparticles such as Au, Ag, Cu
have shape and size dependent optoelectric properties; these are widely utilized as
sensing materials for environmental applications [58]. Plasmonic nanoparticles
have promising approaches as electrochemical sensors, due to the high stability;
these are produced the robust potential for on-site detection of water pollutants [59,
60]. Generally, carbon-based nanomaterials are widely used in electrochemical
applications due to their low cost, high chemical stability, and electrocatalytic
activity for the different redox reactions [61, 62]. Among the carbonaceous materials, graphene-based nanomaterials have wonderful potential for electrochemical
application as unique electrode materials, which have enhanced electron transfer
rate, high signal to noise ratio, and they increased the mass transfer rate [63]. The
hydroxyl and carboxyl group present in the graphene surface may interact with
organic pollutants molecules, and form complexes with pollutant metal ions result
in high sensing activity of the graphene-based composite materials [64, 65].
Graphene-based electrochemical sensors have the ability to detect individual ions as
well as multiple metal ions up to a low detection limit and which can detect metal
ion concentration deviation in the groundwater sample.
92
M. J. Deka et al.