Biomedical Engineering Reference
In-Depth Information
miniaturized devices with the opportunity of using disposables in various fields
of application for faster, automated, and less subjective or error prone. In addi-
tion, the nano-enabled biosensors allow for the analysis of genetic structures
and their influence on cellular functions and this shifts the medicine focus from
diagnosis and treatment to identification and prevention. By combining nano-
enabled diagnosis and therapeutics, nanotechnology is predicted to eventu-
ally lead to production of individually tailored patient-specific treatments and
therapies.
Inorganic semiconductor QDs have emerged as novel fluorescent labels
in biosensing and imaging, and are substituting the conventional organic
fluorophores. This is ascribed to great advantages of inorganic nanocrys-
tals over the conventional organic dyes. Semiconductor QDs exhibit broad
excitation profiles, narrow and symmetric emission spectra, high photosta-
bility and high quantum efficiency, and excellent multiplexed detection capa-
bility.
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For example, QDs with different emission wavelengths can be
excited by a single excitation source, while organic dyes with different emis-
sion wavelengths must be excited by multiple excitation sources. Demand
of simultaneous detection of more targets in single assay drives the develop-
ment of inorganic nanocrystal-based fluorescent probes to replace organic
fluorophores.
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Most of past research on the nanostructured biosensors was the proof-of-
concept work that demonstrated the advantages of NMs and nanostructures.
In the future, more efforts need to be made to move the proof-of-concept
studies to the applications of biosensors to the real-world samples. One trend of
future research is the integration of nanostructured sensors with microfluidics
to form lab-on-chip devices. Furthermore, more studies need to be performed
to integrate the nanostructured sensors with signal-processing instruments to
build portable devices for on-site measurement of analytes to meet the need for
on-time (real-time) monitoring of the targets of interest and rapid assessment
of risks. One of the resulting examples is the point-of-care device that has an
increasing need in the commercial market.
Reports on the development and application of submicron-sized fiberoptic
chemical sensors with distal diameters between 20 and 500 nm have been used
with submicron spatial resolution that is achievable using near-field scanning
optical microscopy (NSOM).
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It is worth noting that, different from the tra-
ditional separation between transducers and molecular recognition probes, a
novel tactic is to integrate transducers with molecular recognition probes to
form nano-transducers that recognize the binding events and actively transduce
sensing signals simultaneously.
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In Chapter 5, the role of NMs for drug delivery in cancer, tumor, and other types
of diseases is discussed including a few examples of drug delivery systems (
Fig-
ure 1.4
) for optimizing the effect of drugs and reducing toxic side effects. Several
nanotechnologies, mostly based on NMs can facilitate drug delivery to tumors but
these have to be carefully and meticulously engineered before they can perform
