5.3 Biosensors for Inorganic Contaminants
Besides these organic and microbial contaminants present in wastewater, inorganic
contaminants like heavy metals contributing major role in water pollution. Iron and
steel and industries, metal industries, mining, are the sources of various heavy metals
like chromium, nickel, zinc, cadmium, iron. Similarly other industries like aircraft
plating and finishing industries releases harmful heavy metals like lead and mercury
which are very harmful constituents of wastewater. Excessive accumulation of these
heavy metals has very harmful and toxic effect on plant and animals [115, 116].
Ensafi et al. reported membrane-based 4-hydroxy salophen on tri-acetyl cellulose
membrane optical sensor detect Cd (II) heavy metal present in wastewater.
Limitations associated with this biosensor are that it has low time response and
cannot detect Cd (II) if its concentration is less than 5 lg/L [117]. Pourbasheer et al.
reported a optical biosensor using 6-Bromo-3-(2-methyl-2,3-dihydrobenzo[d]
thiazol-2-yl)-2H-chromen-2 immobilized on triacetyl cellulose membrane used for
detection of Cu (II) in wastewater [118]. Saber and Piskin reported metallothionein
linked quartz crystal, a type of piezoelectric biosensor used in the detection of Zn
(II) and Cd(II) [119]. Detection of Hg(II) using quartz crystal microbalance
biosensor was reported by Chen et al. [120].
6 Conclusion
This chapter summarizes materials used in different types of biosensors for
wastewater detection. Constant efforts have been done in the improvement of
performance of biosensor by incorporating materials with better detection and
signal conversion property. Nanotechnology application in the design of transducers and the biological detection element has catered the improved sensing
mechanism. Material like nano sized graphene has also exhibited enhanced sensitivity and specificity. This 2D nanomaterial exists in a thermodynamically stable
form and provides superior electronics property due to its unique electronic band
structure [121]. The different types of biosensors based on the biological detection
elements and transducers used for detection of pollutants present in water have been
detailed. Also the applications of these biosensors in the detection of inorganic,
organic and microbial contaminants have been discussed. Some of the major
challenges involved in the development of biosensors are difficulty in real time
monitoring and cost of equipment. The development of biosensors involves
researchers from multi-disciplinary background such as biology, electronics and
chemistry. Other problems faced during the development of biosensors are difficulty in immobilization of biological detection elements such as aptamers and
antibodies and their regeneration ability. Thus, all these aspects pose the scope of
future development of biosensors for detection of wastewater pollutants with high
sensitivity and reduced minimum detection limit.
204
R. Sinha et al.
Besides these organic and microbial contaminants present in wastewater, inorganic
contaminants like heavy metals contributing major role in water pollution. Iron and
steel and industries, metal industries, mining, are the sources of various heavy metals
like chromium, nickel, zinc, cadmium, iron. Similarly other industries like aircraft
plating and finishing industries releases harmful heavy metals like lead and mercury
which are very harmful constituents of wastewater. Excessive accumulation of these
heavy metals has very harmful and toxic effect on plant and animals [115, 116].
Ensafi et al. reported membrane-based 4-hydroxy salophen on tri-acetyl cellulose
membrane optical sensor detect Cd (II) heavy metal present in wastewater.
Limitations associated with this biosensor are that it has low time response and
cannot detect Cd (II) if its concentration is less than 5 lg/L [117]. Pourbasheer et al.
reported a optical biosensor using 6-Bromo-3-(2-methyl-2,3-dihydrobenzo[d]
thiazol-2-yl)-2H-chromen-2 immobilized on triacetyl cellulose membrane used for
detection of Cu (II) in wastewater [118]. Saber and Piskin reported metallothionein
linked quartz crystal, a type of piezoelectric biosensor used in the detection of Zn
(II) and Cd(II) [119]. Detection of Hg(II) using quartz crystal microbalance
biosensor was reported by Chen et al. [120].
6 Conclusion
This chapter summarizes materials used in different types of biosensors for
wastewater detection. Constant efforts have been done in the improvement of
performance of biosensor by incorporating materials with better detection and
signal conversion property. Nanotechnology application in the design of transducers and the biological detection element has catered the improved sensing
mechanism. Material like nano sized graphene has also exhibited enhanced sensitivity and specificity. This 2D nanomaterial exists in a thermodynamically stable
form and provides superior electronics property due to its unique electronic band
structure [121]. The different types of biosensors based on the biological detection
elements and transducers used for detection of pollutants present in water have been
detailed. Also the applications of these biosensors in the detection of inorganic,
organic and microbial contaminants have been discussed. Some of the major
challenges involved in the development of biosensors are difficulty in real time
monitoring and cost of equipment. The development of biosensors involves
researchers from multi-disciplinary background such as biology, electronics and
chemistry. Other problems faced during the development of biosensors are difficulty in immobilization of biological detection elements such as aptamers and
antibodies and their regeneration ability. Thus, all these aspects pose the scope of
future development of biosensors for detection of wastewater pollutants with high
sensitivity and reduced minimum detection limit.
204
R. Sinha et al.