Nanobiosensors

1. Nanobiosensors

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…)

4. Functioning of Nanobiosensor
Detector

5. TYPES OF BIOSENSORS
Optical Biosensors
 Electrical Biosensors
 Electrochemical Biosensors
 Nanotube Based Biosensors
 Nanowire Biosensors
 Viral Nanosensors
 Nanoshell Biosensors

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….

7. Optical Nanobiosensors
Two kind of fabrication
methods for optical fiber
tips
1) Heat and Pull Method
2) Chemical Etching

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