89
methods. These methods are time consuming and laborious (Rodriguez-Mozaz
et al. 2007). Additionally, these instruments need column cleanup processes. Based
on this, biosensor systems have shown tremendous promise to overcome these limitations (Rodriguez-Mozaz et al. 2005). This biological technique includes immunoand bioassay method. Microbial biosensors have become one of the popular
molecular tools for monitoring of persistent organic pollutants.
4.3 Biosensor
4.3.1 Definition of Biosensor
A sensor has transducers to sense pollutants in the environment. It detects and provides a corresponding output, generally as an electrical or optical signal. It has an
ideal alternative method for pollutant quantification, as they are the most effective
technique (Turner 2007). The term “biosensor” is in short for “biological sensor”. A
“biosensor” is a self-contained integrated device, consisting of a biological recognition element in direct contact with a transduction element, which converts into a
measurable output signal resulting in qualitative or quantitative identification. The
transducer converts this biological signal into a quantifiable signal (potential, optical, or electronic signal) which can be further improved, processed, and stored for
later analysis (Kaur et al. 2015; Teo and Wong 2014).
4.3.2 Types of Biosensor
Biosensors have been classified based on transduction and biological recognition
elements (Fig. 4.2). Biosensors have been constructed based on the interactions
between antibodies and antigen, enzymes and their substrates, or the affinity of
nucleic acid strand to their complementary sequences. Biosensor selectivity and
specificity are highly depended on biological recognition systems connected to a
suitable transducer. Recently, biosensor researchers are highly attracted by recognition molecules such as phages, molecular imprinted polymers, and affibody that are
Table 4.1 (continued)
Pollutant
Permissible
limit
Detection limits for
analytical techniques Target effects
References
Perfluorinated compounds
Perfluorooctanoic acid
70 ppt
1 ng/L (Liquid
chromatograph- mass
spectrometer)
Reproductive,
developmental
toxicities and etc.
US EPA
(2014,
2016)
Perfluorooctane
sulphonate
4 Genetically Modified Microbial Biosensor for Detection of Pollutants in Water…
methods. These methods are time consuming and laborious (Rodriguez-Mozaz
et al. 2007). Additionally, these instruments need column cleanup processes. Based
on this, biosensor systems have shown tremendous promise to overcome these limitations (Rodriguez-Mozaz et al. 2005). This biological technique includes immunoand bioassay method. Microbial biosensors have become one of the popular
molecular tools for monitoring of persistent organic pollutants.
4.3 Biosensor
4.3.1 Definition of Biosensor
A sensor has transducers to sense pollutants in the environment. It detects and provides a corresponding output, generally as an electrical or optical signal. It has an
ideal alternative method for pollutant quantification, as they are the most effective
technique (Turner 2007). The term “biosensor” is in short for “biological sensor”. A
“biosensor” is a self-contained integrated device, consisting of a biological recognition element in direct contact with a transduction element, which converts into a
measurable output signal resulting in qualitative or quantitative identification. The
transducer converts this biological signal into a quantifiable signal (potential, optical, or electronic signal) which can be further improved, processed, and stored for
later analysis (Kaur et al. 2015; Teo and Wong 2014).
4.3.2 Types of Biosensor
Biosensors have been classified based on transduction and biological recognition
elements (Fig. 4.2). Biosensors have been constructed based on the interactions
between antibodies and antigen, enzymes and their substrates, or the affinity of
nucleic acid strand to their complementary sequences. Biosensor selectivity and
specificity are highly depended on biological recognition systems connected to a
suitable transducer. Recently, biosensor researchers are highly attracted by recognition molecules such as phages, molecular imprinted polymers, and affibody that are
Table 4.1 (continued)
Pollutant
Permissible
limit
Detection limits for
analytical techniques Target effects
References
Perfluorinated compounds
Perfluorooctanoic acid
70 ppt
1 ng/L (Liquid
chromatograph- mass
spectrometer)
Reproductive,
developmental
toxicities and etc.
US EPA
(2014,
2016)
Perfluorooctane
sulphonate
4 Genetically Modified Microbial Biosensor for Detection of Pollutants in Water…