2. tion
A biosensor is a measurement system for the
detection of an analyte that combines a biological
component with a physicochemical detector, and a
nanobiosensor is a biosensor that on the nano-scale size
What is a Nanobiosensor?
3. Nanobiosensor
Transducer Detector Biological Recognition Element
(Bioreceptor)
Living biological system
(cell, tissue or whole organism)
Biological molecular species
(antibody, enzyme, protein…)
6. Optical Nanobiosensors
A sensor that uses light to detect the effect of a
chemical on a biological system.
The small size of the optical fibers allow sensing
intracelular intercelular physiological and biological
parameter in micro- environment.
Continued….
8. Nanowire Field Effect Nanobiosensors
(FET)
Semiconductor channel (nanowire) of the transistor.
The semiconductor channel is fabricated using
nanomaterials such a carbon nanotubes,metal oxide
nanowires or Si nanowires.
Very high surface to volume radio and very large
portion of the atoms are located on the surface
Extremely sensitive to environment
9. Piezo-Electric Biosensors
Some piezo-electric devices utilize
crystals, such as quartz, which vibrate under
the influence of an electric field. The
frequency of this oscillation depends on
their thickness and cut.
Very high surface to volume radio and
very large portion of the atoms are located
on the surface Extremely sensitive to
environment.
Others use gold to detect the specific
angle at which electron waves (surface
plasmons) are emitted when the substance
is exposed to laser light.
The change in frequency is proportional
to the mass of absorbed material.
10. Electrochemical Biosensors
Amperometric for applied current: Movement of
e- in redox reactions detected when a potential is
applied between two electrodes.
Potentiometric for voltage: Change in distribution
of charge is detected using ion-selective electrodes,
such as pH-meters.
Conductimetric for impedance
11. Applications of Nanobiosensors
Biological Applications
DNA Sensors: Genetic monitoring, disease
Immunosensors: HIV, Hepatitis,other viral diseas,
drug testing, environmental monitoring…
Cell-based Sensors: functional sensors, drug testing…
Point-of-care sensors: blood, urine, electrolytes,
gases, steroids, drugs, hormones, proteins, other…
Bacteria Sensors (E-coli, streptococcus, other): food
industry, medicine, environmental, other.
Enzyme sensors: diabetics, drug testing, other.
Environmental Applications
Detection of environmental pollution and toxicity
Agricultural monitoring
Ground water screening
Ocean monitoring
12. Future Applications of Nanobiosensors
Cancer Monitoring
Nanobiosensors play a very important role for early cancer
detection in body fluids.
The sensor is coated with a cancer-specific antibody or other
biorecognation ligands. The capture of a cancer cell or a target
protein yields electrical, optical or mechanical signal for detection.
Identification of Biomarkers
↓
Validation of Cancer Biomarkers
↓
Cancer Biomarkers
↓
Ligands / Probes Developments
↓
Cancer Diagnostics Biosensor ← Detector
↓
Point of Care Cancer Diagnostics