Nanomaterials: An Introduction
3
mutation or gene acquisition. Therefore, new classes of antibiotics with novel structures are needed to combat this trend. Food preservation is now dealing with the
severe concern of microorganisms mediated spoilage and fall in quality and nutrition worldwide [32]. Hence, increasing the continuous demand for pathogen control
measures to combat resistant microorganisms against multiple antimicrobial agents.
However, nanoparticles own large surface area to volume ratio, unique quantum size,
magnetic properties, heat conductivity in addition to some catalytic and antimicrobial
properties [33]. In this regard, nanomaterials, including metal nanoparticles, carbon
nanotubes, quantum dots, and other active nanomaterials can be used to develop
biosensors against a broad spectrum of microorganisms for the formulation of a new
generation of antimicrobial agents.
2 Historical Background of Nanotechnology
The first experiment of nanotechnology was shown in 1857 when Michael Faraday
introduced ‘gold colloid’ samples to the Royal Society. He added phosphorous to
a solution of gold chloride and, after a short while, noted that the blue color of
the solution changed to a ruby red dispersion, without knowing the actual cause
of color changing. Indeed, the resulting suspension of nanosized gold particles in
solution appeared transparent at some frequencies, but others could look colored
(ruby, green, violet, or blue). Since then, many experiments and theoretical studies
have been carried out to explain similar systems’ unique properties, which in today’s
terminology are called low-dimensional systems. Nearly after 100 years, in 1959,
Richard Feynman inspired the field of nanotechnology in his lecture at the American
Physical Society (APS) meeting, Caltech, saying the meaningful words “There’s
Plenty of Room at the Bottom.” From the late 1980s, we find there is a growth of
activity on these low dimensional materials. In general, low dimensional systems
are categorized as follows: (a) two dimensional (2D) systems, in which the electrons
are confined in a plane (e.g., Layered structures, quantum wells and superlattices);
(b) one dimensional (1D) systems, in which electrons are free to move only in one
dimension (e.g., linear chain-like structures, semiconductor quantum wires), and (c)
zero-dimensional (0D) systems, where electrons are confined in all three dimensions
(e.g., quantum dots, clusters, and nanosized colloidal particles) [34–41].
The dimension of these materials in the direction of confinement lies in the
nanometer scale, given the name nanomaterials. In this length scale, classical physics
fails to explain the behavior of these materials. Instead, one needs quantum mechanical concepts. Interestingly, due to quantum effects, the physical properties of nanomaterials change drastically from their corresponding bulk behavior. This unique
feature of nanomaterials has been exploited by modern technology in various applications. The link between human life and nanotechnology is as old as Ayurveda, a
5000-year-old Indian medicine system.
Moreover, twenty-first century modern science marks the beginning of
nanoscience, while it existed from ancient times of Vedas, much before even the
3
mutation or gene acquisition. Therefore, new classes of antibiotics with novel structures are needed to combat this trend. Food preservation is now dealing with the
severe concern of microorganisms mediated spoilage and fall in quality and nutrition worldwide [32]. Hence, increasing the continuous demand for pathogen control
measures to combat resistant microorganisms against multiple antimicrobial agents.
However, nanoparticles own large surface area to volume ratio, unique quantum size,
magnetic properties, heat conductivity in addition to some catalytic and antimicrobial
properties [33]. In this regard, nanomaterials, including metal nanoparticles, carbon
nanotubes, quantum dots, and other active nanomaterials can be used to develop
biosensors against a broad spectrum of microorganisms for the formulation of a new
generation of antimicrobial agents.
2 Historical Background of Nanotechnology
The first experiment of nanotechnology was shown in 1857 when Michael Faraday
introduced ‘gold colloid’ samples to the Royal Society. He added phosphorous to
a solution of gold chloride and, after a short while, noted that the blue color of
the solution changed to a ruby red dispersion, without knowing the actual cause
of color changing. Indeed, the resulting suspension of nanosized gold particles in
solution appeared transparent at some frequencies, but others could look colored
(ruby, green, violet, or blue). Since then, many experiments and theoretical studies
have been carried out to explain similar systems’ unique properties, which in today’s
terminology are called low-dimensional systems. Nearly after 100 years, in 1959,
Richard Feynman inspired the field of nanotechnology in his lecture at the American
Physical Society (APS) meeting, Caltech, saying the meaningful words “There’s
Plenty of Room at the Bottom.” From the late 1980s, we find there is a growth of
activity on these low dimensional materials. In general, low dimensional systems
are categorized as follows: (a) two dimensional (2D) systems, in which the electrons
are confined in a plane (e.g., Layered structures, quantum wells and superlattices);
(b) one dimensional (1D) systems, in which electrons are free to move only in one
dimension (e.g., linear chain-like structures, semiconductor quantum wires), and (c)
zero-dimensional (0D) systems, where electrons are confined in all three dimensions
(e.g., quantum dots, clusters, and nanosized colloidal particles) [34–41].
The dimension of these materials in the direction of confinement lies in the
nanometer scale, given the name nanomaterials. In this length scale, classical physics
fails to explain the behavior of these materials. Instead, one needs quantum mechanical concepts. Interestingly, due to quantum effects, the physical properties of nanomaterials change drastically from their corresponding bulk behavior. This unique
feature of nanomaterials has been exploited by modern technology in various applications. The link between human life and nanotechnology is as old as Ayurveda, a
5000-year-old Indian medicine system.
Moreover, twenty-first century modern science marks the beginning of
nanoscience, while it existed from ancient times of Vedas, much before even the