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?
Transducer Detector Biological Recognition Element
Living biological system
(cell, tissue or whole organism)
Biological molecular species
(antibody, enzyme, protein…)
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.
Two kind of fabrication
methods for optical fiber
1) Heat and Pull Method
2) Chemical Etching
Nanowire Field Effect Nanobiosensors
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
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
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.
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
Applications of Nanobiosensors
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.
Detection of environmental pollution and toxicity
Ground water screening
Future Applications of Nanobiosensors
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
Ligands / Probes Developments
Cancer Diagnostics Biosensor ← Detector
Point of Care Cancer Diagnostics