Page 141 - Polymer-based Nanocomposites for Energy and Environmental Applications

116 Polymer-based Nanocomposites for Energy and Environmental Applications

Fig. 4.13 Sensing of ozone [69].

relative humidity. In other studies, C 20 fullerene and graphene segment were used in
sensing ozone of the troposphere [69], shown in Fig. 4.13 [69].
Recently, phenol that is a protoplasmic poison having a virulent impact on all living
organisms like plants, animals, and humans gets detected by graphene sensors.
Researchers report impedance-based phenol sensing by using electrochemically
RGO-modified screen-printed electrode (SPE) [36]. In other interesting study, nitrite
detection was made by modified glassy carbon electrodes (GCE) by using newly
synthesized GNs [70]. Since the presence of high level of nitrite in drinking water
leads to several diseases in human health such as methemoglobinemia and stomach
cancer by the production of N-nitrosamines [70] and also contaminates the agriculture
soil and food materials, developed sensor is highly effective for the determination of
nitrite in drinking water samples, as it offers several advantages including high sen-
sitivity, selectivity, wide linear range, and low detection limit, along with simplicity
and cost-effectiveness of electrode preparation [71]. In another finding, AuPd/reduced
GO composite was employed as a novel electrode material for the simultaneous and
selective determination of acetaminophen, ascorbic acid, and tyrosine [72].
Progesterone (4-pregnone-3,20 dione, P4) is a nonsaturated α,β-ketone, important
for the maintenance and stabilization of pregnancy in mammals. However, an imbal-
ance of P4 in the human organism can cause malformations of the reproductive system
and infertility problems. Until now, various techniques have been employed for P4
determination, including high-performance liquid chromatography (HPLC) and liquid
chromatography (LC) coupled with different detectors (DAD [73],UV [74],MS [75],
and DCE [76]), time-resolved fluoroimmunoassay [77], fluorescent immunoassay
[78], and chemiluminescence enzyme immunoassay (CLEIA) [79]. However, assem-
bling of nanomaterials, such as Fe 3 O 4 , GQDs, and MWCNTs, generates a versatile
3-D hybrid network with synergic and electrocatalytic characteristics that are
currently receiving great attention [80]. Research study indicated that
Fe 3 O 4 @GQD/f-MWCNT nanocomposite-based modified electrodes are highly fast,
accurate, and sensitive for P4 detection. In another interesting work, novel enzymatic
H 2 O 2 sensor based on PGN and HRP was developed and provides a pathway in the