regular detection and monitoring of the levels of such harmful contaminants is
essential for maintenance of suitable water quality. The application of nanosensors
for detection of some major pathogens, organic and heavy metal water pollutants are
discussed in this chapter.
Mercury (Hg), lead (Pb), cadmium (Cd), chromium (Cr) and arsenic are major
highly toxic heavy metal contaminants of aquatic systems. Exposure to these metals
can cause health problems like kidney failure, effect on central nervous system, high
blood pressure, etc. Recently, extensive research has been performed for development of nano- and nanobiosensors for detection of these pollutants from water
sources. Majorly, electrochemical and optical methods have been used for sensing
applications due to their rapid response and high sensitivity. Cho et al. (2010)
developed porphyrin derivative modified Au@SiO 2 NPs for efficient colorimetric
detection of Hg
2+ .
Niu et al. (2015) developed bismuth (Bi) NPs and porous carbon nanocomposite
modified screen-printed electrodes (SPE), and used this nanosensor for electrochemical detection of Ni
2+ , Pb
2+ and Cd
2+ with LOD of 5.47, 0.65 and 0.81 ppb,
respectively. Detection was performed in tap water and waste water samples. The
high surface area of Bi NPs and porous nature of carbon matrix facilitated the
detection. Veera Kumar et al. (2016) developed a Pd NPs/porous activated carbons
(PACs) modified GCE nanosensing platform for highly sensitive simultaneous
detection of Hg
2+ , Pb
2+ , Cu
2+ and Cd
2+ with respective LOD values 54, 50,
66 and 41 nM.
Nanosensors technology has emerged as an promising platform for detection of a
large number of organic compounds from water sources, such as amino acids, thiols,
poly aromatic hydrocarbons (PAHs), phenol and its derivatives, nitro-aromatic
compounds, pesticides, etc.
Sadeghi et al. (2013) reported effective voltammetric detection of phenol in water
using p-chloranil and CNTs modified graphite paste composite electrode. The
nanosensors displayed high selectivity for phenol without interference of
800-times presence of other potential interfering substances.
Nitro-aromatic compounds also constitute major water contaminants.
Compounds like paranitrophenol (4-NP) are highly used industrial chemicals.
While, chemicals like trinitrotoluene (TNT), and dinitrotoluene are released from
explosives. These chemicals can cause numerous severe health issues, thus making
their detection significant for monitoring water quality.
Cerruti et al. (2009) achieved highly selective detection of TNT by using phage
display method. TNT oligopeptide receptor was immobilized on PEGM polymer
matrix, and deposited on a quartz crystal microbalance (QCM). Decrease in the
QCM resonance frequency on the presence of TNT was used for detection. The
sensor showed selectivity for TNT over DNT.
Highly selective 4-NP fluorescent detection was reported by Zhou et al. (2014) by
using a composite of molecularly imprinted polymer (MIP) and graphene QDs
(GQDs). Good specificity for recognition of 4-NP was provided by MIP, and
GQDs act as donor for resonance energy transfer.
5 Development of Environmental Nanosensors for Detection Monitoring. . .
123
essential for maintenance of suitable water quality. The application of nanosensors
for detection of some major pathogens, organic and heavy metal water pollutants are
discussed in this chapter.
Mercury (Hg), lead (Pb), cadmium (Cd), chromium (Cr) and arsenic are major
highly toxic heavy metal contaminants of aquatic systems. Exposure to these metals
can cause health problems like kidney failure, effect on central nervous system, high
blood pressure, etc. Recently, extensive research has been performed for development of nano- and nanobiosensors for detection of these pollutants from water
sources. Majorly, electrochemical and optical methods have been used for sensing
applications due to their rapid response and high sensitivity. Cho et al. (2010)
developed porphyrin derivative modified Au@SiO 2 NPs for efficient colorimetric
detection of Hg
2+ .
Niu et al. (2015) developed bismuth (Bi) NPs and porous carbon nanocomposite
modified screen-printed electrodes (SPE), and used this nanosensor for electrochemical detection of Ni
2+ , Pb
2+ and Cd
2+ with LOD of 5.47, 0.65 and 0.81 ppb,
respectively. Detection was performed in tap water and waste water samples. The
high surface area of Bi NPs and porous nature of carbon matrix facilitated the
detection. Veera Kumar et al. (2016) developed a Pd NPs/porous activated carbons
(PACs) modified GCE nanosensing platform for highly sensitive simultaneous
detection of Hg
2+ , Pb
2+ , Cu
2+ and Cd
2+ with respective LOD values 54, 50,
66 and 41 nM.
Nanosensors technology has emerged as an promising platform for detection of a
large number of organic compounds from water sources, such as amino acids, thiols,
poly aromatic hydrocarbons (PAHs), phenol and its derivatives, nitro-aromatic
compounds, pesticides, etc.
Sadeghi et al. (2013) reported effective voltammetric detection of phenol in water
using p-chloranil and CNTs modified graphite paste composite electrode. The
nanosensors displayed high selectivity for phenol without interference of
800-times presence of other potential interfering substances.
Nitro-aromatic compounds also constitute major water contaminants.
Compounds like paranitrophenol (4-NP) are highly used industrial chemicals.
While, chemicals like trinitrotoluene (TNT), and dinitrotoluene are released from
explosives. These chemicals can cause numerous severe health issues, thus making
their detection significant for monitoring water quality.
Cerruti et al. (2009) achieved highly selective detection of TNT by using phage
display method. TNT oligopeptide receptor was immobilized on PEGM polymer
matrix, and deposited on a quartz crystal microbalance (QCM). Decrease in the
QCM resonance frequency on the presence of TNT was used for detection. The
sensor showed selectivity for TNT over DNT.
Highly selective 4-NP fluorescent detection was reported by Zhou et al. (2014) by
using a composite of molecularly imprinted polymer (MIP) and graphene QDs
(GQDs). Good specificity for recognition of 4-NP was provided by MIP, and
GQDs act as donor for resonance energy transfer.
5 Development of Environmental Nanosensors for Detection Monitoring. . .
123