Optical arrays based on chemical dyes (nanoporous dyes and pigments) study the chemical reaction of analytes instead of their physical properties. It provides high dimensions for chemical sensing that causes high sensitivity, often (ppb) or even (ppt), and significant discrimination between very similar analytes, and fingerprints of very similar mixtures, in a wide range of analytes in both gaseous and liquid phases. Thus, calorimetric and fluorometric sensor arrays effectively overcome the limitations of traditional array-based sensors that rely solely on physical absorption or nonspecific chemical reactions. Such optical array measurements have shown excellent performance in tracking and identifying a variety of analytes, from hazardous chemicals to energetic explosives, medical biomarkers, and food additives. New sensor technologies must inevitably face the dilemma of trying to create sensors that are increasingly both sensitive and powerful. Obsolete or worn sensors are a specific problem for any sensor array, regardless of the class of sensors, it intends to reuse. For pattern recognition to work, the pattern library must reflect the sensors' responses at the time of immediate use. If the sensor response deviates, libraries can become obsolete very quickly. One way to solve this problem is to use disposable sensors, which therefore cut off the various demands that challenge the development of chemical sensing. Current array-based detectors of a variety of analytical strategies for tracking even subtle changes in physical properties (e. g. , molecular weight, conductivity, surface tension) or chemical reaction (e. g. , Lewis acidity/base, hydrogen bonding, potential Oxidation) have been used. Including the use of conductive polymers and polymer composites, metal oxide semiconductors, quartz crystal microbalances, polymer-coated surface acoustic wave devices, and fluorescent molecular frameworks. Chemical sensors that have existed for odor analysis so far can generally be classified into optical and non-optical types through signal transmission approaches. The classification of these sensors is mainly based on their use of the physical properties of the analytes or the chemical interactions of the analytes. Electrochemical sensors detect signal changes in resistance, for example, from an electric current flowing through electrodes that come into contact with and interact with chemical analytes. Mass sensors measure the difference in mass of the sensor surface when exposed to the analytes. Optical sensors convert changes in electromagnetic waves (for example, UV-vis) into electronic signals [79]. In general, chemical sensors are divided into optical and non-optical.
Optical
arrays
based on
chemical
dyes (
nanoporous
dyes and pigments) study the
chemical
reaction of analytes
instead
of their
physical
properties. It provides high dimensions for
chemical
sensing that causes high sensitivity,
often
(ppb) or even (
ppt
), and significant discrimination between
very
similar analytes, and fingerprints of
very
similar mixtures, in a wide range of analytes in both gaseous and liquid phases.
Thus
,
calorimetric
and
fluorometric
sensor
arrays
effectively
overcome the limitations of traditional array-based sensors that rely
solely
on
physical
absorption or nonspecific
chemical
reactions. Such optical
array
measurements have shown excellent performance in tracking and identifying a variety of analytes, from hazardous
chemicals
to energetic explosives, medical biomarkers, and food additives. New sensor technologies
must
inevitably
face the dilemma of trying to create sensors that are
increasingly
both sensitive and powerful. Obsolete or worn sensors are a specific problem for any sensor
array
, regardless of the
class
of sensors, it intends to reuse. For pattern recognition to work, the pattern library
must
reflect the sensors' responses at the time of immediate
use
. If the sensor response deviates, libraries can become obsolete
very
quickly
. One way to solve this problem is to
use
disposable sensors, which
therefore
cut
off the various demands that challenge the development of
chemical
sensing.
Current
array-based detectors of a variety of analytical strategies for tracking even subtle
changes
in
physical
properties (
e. g.
,
molecular weight, conductivity, surface tension) or
chemical
reaction (
e. g.
,
Lewis acidity/base, hydrogen bonding, potential Oxidation) have been
used
. Including the
use
of conductive polymers and polymer composites, metal oxide semiconductors, quartz crystal microbalances, polymer-coated surface acoustic wave devices, and fluorescent molecular frameworks.
Chemical
sensors that have existed for odor analysis
so
far can
generally
be classified
into optical and non-optical types through signal transmission approaches. The classification of these sensors is
mainly
based on their
use
of the
physical
properties of the analytes or the
chemical
interactions of the analytes. Electrochemical sensors detect signal
changes
in resistance,
for example
, from an electric
current
flowing through electrodes that
come
into contact with and interact with
chemical
analytes. Mass sensors measure the difference in mass of the sensor surface when exposed to the analytes. Optical sensors convert
changes
in electromagnetic waves (
for example
,
UV-vis
) into electronic signals [79].
In general
,
chemical
sensors
are divided
into optical and non-optical.