resonance, fixed in a plastic optical fiber that acts as a cost-effective, optical sensing
platform along with a molecularly imprinted polymer layer specific for the chemical
marker, placed in contact with a thin film of gold. These specific molecular imprint
polymers on the gold film form a distinct dielectric medium with optical properties
like the refractive index. That would influence the sensing, upon the interaction of
the target analyte to the receptor polymers imprinted on the gold film. Dibenzyl
disulfide (DBDS) is known to be accountable for the corrosiveness of the mineral
insulating oil used for transformer (De Maria et al. 2018). Thus, it is of paramount
importance to determine its concentration in mineral oil for diagnostic purposes of
the transformer. Also, furfuraldehyde, one among the major byproducts formed
during degradation of the insulation paper in a transformer upon overheating. Its
presence in the transformer’s insulation oil could verify the status of the solid
insulation in transformers, which could otherwise become an environmental hazard
to many lives.
10.3 Biosensors
Biosensors have significant roles in human health care in the diagnostic procedures
to find infections and to prevent epidemics by means of rapid detection techniques
(Brindha et al. 2018a; Ellwanger et al. 2017; Du and Zhou 2018; Kaushik et al.
2017). They are analytical devices that work based on the recognition of biological
target molecules such as microorganisms, peptide molecules, nucleic acids, proteins,
or any biomolecule. The results from an ideal biosensor should be reproducible,
sensitive, selective, stabile, and linear (Bhalla et al. 2016). Biosensors possess a
biological targeting element that can selectively bind/interact with the target analytes
and delivers an output signal depending on the extent of interaction which is then
converted to a readable format by a transducer before being transferred to a reader
device. The most commonly used biosensors include fluorescent label-based
biosensors, surface plasmon resonance biosensors, piezoelectric biosensors, electrochemical biosensors, and biochemical/immuno-biosensors.
10.3.1 Fluorescent Label-Based Biosensor
Fluorescent labeling method (Li et al. 2015) works by energizing a fluorophore at a
particular wavelength and observing the photons emitted at another wavelength in a
time scale of microsecond. The common fluorophores such as calcein blue, quantum
dots (Resch-Genger et al. 2008), carbon dots, and fluorescent diacetate are mostly
employed as labels for signal recognition/probe molecules, when the targeted biomolecule under detection is in trace amounts in the sample. Calcein blue is one of the
most commonly used blue fluorescent labels that possess the ability to detect and
quantify pathogens (Sankaranarayanan et al. 2015). Here, the siderophores released
by the bacteria can chelate Fe
2+ from the iron-bound calcein blue to restore its
fluorescence, which is further utilized for detecting the iron chelators quantitatively
10 Environment Remediation Tools: Chemosensors and Biosensors
275
platform along with a molecularly imprinted polymer layer specific for the chemical
marker, placed in contact with a thin film of gold. These specific molecular imprint
polymers on the gold film form a distinct dielectric medium with optical properties
like the refractive index. That would influence the sensing, upon the interaction of
the target analyte to the receptor polymers imprinted on the gold film. Dibenzyl
disulfide (DBDS) is known to be accountable for the corrosiveness of the mineral
insulating oil used for transformer (De Maria et al. 2018). Thus, it is of paramount
importance to determine its concentration in mineral oil for diagnostic purposes of
the transformer. Also, furfuraldehyde, one among the major byproducts formed
during degradation of the insulation paper in a transformer upon overheating. Its
presence in the transformer’s insulation oil could verify the status of the solid
insulation in transformers, which could otherwise become an environmental hazard
to many lives.
10.3 Biosensors
Biosensors have significant roles in human health care in the diagnostic procedures
to find infections and to prevent epidemics by means of rapid detection techniques
(Brindha et al. 2018a; Ellwanger et al. 2017; Du and Zhou 2018; Kaushik et al.
2017). They are analytical devices that work based on the recognition of biological
target molecules such as microorganisms, peptide molecules, nucleic acids, proteins,
or any biomolecule. The results from an ideal biosensor should be reproducible,
sensitive, selective, stabile, and linear (Bhalla et al. 2016). Biosensors possess a
biological targeting element that can selectively bind/interact with the target analytes
and delivers an output signal depending on the extent of interaction which is then
converted to a readable format by a transducer before being transferred to a reader
device. The most commonly used biosensors include fluorescent label-based
biosensors, surface plasmon resonance biosensors, piezoelectric biosensors, electrochemical biosensors, and biochemical/immuno-biosensors.
10.3.1 Fluorescent Label-Based Biosensor
Fluorescent labeling method (Li et al. 2015) works by energizing a fluorophore at a
particular wavelength and observing the photons emitted at another wavelength in a
time scale of microsecond. The common fluorophores such as calcein blue, quantum
dots (Resch-Genger et al. 2008), carbon dots, and fluorescent diacetate are mostly
employed as labels for signal recognition/probe molecules, when the targeted biomolecule under detection is in trace amounts in the sample. Calcein blue is one of the
most commonly used blue fluorescent labels that possess the ability to detect and
quantify pathogens (Sankaranarayanan et al. 2015). Here, the siderophores released
by the bacteria can chelate Fe
2+ from the iron-bound calcein blue to restore its
fluorescence, which is further utilized for detecting the iron chelators quantitatively
10 Environment Remediation Tools: Chemosensors and Biosensors
275