detection techniques using plasmonic nanoparticles decorated 2D nanosheet are
also briefly discussed in this chapter.
Keywords Graphene Á Plasmonic nanoparticle Á Surface plasmon resonance
(SPR) Á Water pollutants
1 Introduction
In the 21st century, many of the major problems like human health, environmental
pollution, water safety are the principle concern issues all over the world. In this
century, the problem that humanity is facing related to the quantity and quality of
water. These problems are globally recognized, and there is an adverse effect on
climate change, water cycle intensification, melting of glaciers, etc. [1–4]. Many
hazardous pollutants (heavy metal ions, organic contaminants, dyes, pesticides,
etc.) present in the groundwater, surface water create a severe threat in the environment as well as in drinking water. Concerning human health, more than
one-third of the people in the world facing severe problem like improved sanitation,
lack of clean drinking water [5–7]. Water is the most vital part of human beings,
which includes every field of energy, health, economy, food, etc. Some statistical
reports show near about 10–20 million people die every year due to nonfatal and
waterborne illness, and 5000–6000 children die due to diarrhea every day. It is a
matter of serious havoc that the current water supply will be reduced by one-third
after a couple of decades [8–12].
Single layered graphene sheet was discovered by A. K. Geim and his co-workers
from graphite using a “Scotch Tape” approach in 2004 [13, 14]. For the discovery
of graphene, A. K. Geim and Konstantin Novoselov were awarded jointly Nobel
Prize in Physics in 2010. There are mostly two forms of functionalized graphene,
e.g. graphene oxide (GO) and reduced graphene oxide [15–17]. There are different
routes of reduction of graphene oxide, the partial reduction (physical and chemical)
of oxygenated functional groups of GO is termed as reduced graphene oxide
(rGO) [18, 19]. Another form of fluorescent graphene is graphene quantum dots
(GQDs) which is prepared by cutting the larger lateral dimension of graphene
sheets, making it 0D as well as lateral size of few nanometers. These carbon hybrid
materials (graphene, GO, rGO, GQDs) possess some outstanding properties like
optical, water-solubility, photostability, biocompatibility, nontoxic inexpensive,
photo-stable, and environmentally friendly and many more. Thus, these materials
are widely used in various field like in fluorescent biosensors, chemical-sensors, in
which they either serve as fluorophores or quenchers, electronic devices, molecular
sensors, nanocomposites, supercapacitors, batteries, hydrogen storage device, etc.
As fluorophores, they show tunable photoluminescence emission (fluorescence) and
excitation-dependent emission property due to “Giant Red-Edge Effect” [20, 21].
There are different techniques reported to date for the synthesis of graphene,
functionalized graphene, and GQDs. The reported methods are exfoliation and
80
M. J. Deka et al.
also briefly discussed in this chapter.
Keywords Graphene Á Plasmonic nanoparticle Á Surface plasmon resonance
(SPR) Á Water pollutants
1 Introduction
In the 21st century, many of the major problems like human health, environmental
pollution, water safety are the principle concern issues all over the world. In this
century, the problem that humanity is facing related to the quantity and quality of
water. These problems are globally recognized, and there is an adverse effect on
climate change, water cycle intensification, melting of glaciers, etc. [1–4]. Many
hazardous pollutants (heavy metal ions, organic contaminants, dyes, pesticides,
etc.) present in the groundwater, surface water create a severe threat in the environment as well as in drinking water. Concerning human health, more than
one-third of the people in the world facing severe problem like improved sanitation,
lack of clean drinking water [5–7]. Water is the most vital part of human beings,
which includes every field of energy, health, economy, food, etc. Some statistical
reports show near about 10–20 million people die every year due to nonfatal and
waterborne illness, and 5000–6000 children die due to diarrhea every day. It is a
matter of serious havoc that the current water supply will be reduced by one-third
after a couple of decades [8–12].
Single layered graphene sheet was discovered by A. K. Geim and his co-workers
from graphite using a “Scotch Tape” approach in 2004 [13, 14]. For the discovery
of graphene, A. K. Geim and Konstantin Novoselov were awarded jointly Nobel
Prize in Physics in 2010. There are mostly two forms of functionalized graphene,
e.g. graphene oxide (GO) and reduced graphene oxide [15–17]. There are different
routes of reduction of graphene oxide, the partial reduction (physical and chemical)
of oxygenated functional groups of GO is termed as reduced graphene oxide
(rGO) [18, 19]. Another form of fluorescent graphene is graphene quantum dots
(GQDs) which is prepared by cutting the larger lateral dimension of graphene
sheets, making it 0D as well as lateral size of few nanometers. These carbon hybrid
materials (graphene, GO, rGO, GQDs) possess some outstanding properties like
optical, water-solubility, photostability, biocompatibility, nontoxic inexpensive,
photo-stable, and environmentally friendly and many more. Thus, these materials
are widely used in various field like in fluorescent biosensors, chemical-sensors, in
which they either serve as fluorophores or quenchers, electronic devices, molecular
sensors, nanocomposites, supercapacitors, batteries, hydrogen storage device, etc.
As fluorophores, they show tunable photoluminescence emission (fluorescence) and
excitation-dependent emission property due to “Giant Red-Edge Effect” [20, 21].
There are different techniques reported to date for the synthesis of graphene,
functionalized graphene, and GQDs. The reported methods are exfoliation and
80
M. J. Deka et al.