nanotechnology: nano engineered cell environment and nanosensors.

1. NANOENGINEERED CELL
ENVIRONMENT AND
NANOSENSOR
By
Keerthana V
17PBT010
Nanobiotechnology and
food biotechnology

2. INTRODUCTION
Inside a living cell – numerous biological process & biochemical
reactions occurs in subcellular organells.
Compartmentalized and dynamically change – physical and chemical
properties.
Tracking the regulation- reveals function and mechanism.

3. To measure intracellular properties... Microsystems and
nanoengineered tools are developed..
Thethered measurement methods ( nanowires, nanotubes and
modified atomic force microscopy(AFM)
Untethered sensing approaches ( nanoparticlals , fluorescent proteins
(FP) and molecules and untethered microeletromechanical system
(MEMS) devices)
Tethered sensing technologies : invasive to the cell membrane
Untethered sensors : delivered into the cell.. So no damage

4. TETHERED INTRACELLULAR
SENSING
an intracellular probe transforms detected intracellular quantities into
electrical/ photonic signals and transmit to external instrument via
tethering connections.
inexpensive but damage cells
Overcome : developed probe using nanowires , carbon nanotubes
(CNTS)..

5. UNTETHERED INTRACELLULAR
SENSING
Device perform intracellular measurement without connecting to
extracellular instruments.
Advantage :
Cell membrane remains intact – produced internally ( cellular
machineries ) / or introduced into the cell via passive drug delivery
(endocytosis).
Sensors move along with cell structure- migration and mitosis
Suitable – long term intracellular measurement.

6. INTRACELLULAR MANIPULATION
Delivery:
To perform intracellular measurements – requires delivery of foreign
material into cell.
Microinjection : mechanical process – uses sharp micropipette (0.5 to
5µm) - deliver membrane impermeable material into cell.
CNT (carbon nanotubes) nanopipette – less invasive to cell, requires
very high pressure and small volume liquid – delivered into cell.
AFM nanoneedles: capability of accessing the interior of living cell.
Proteins and DNA immobilized on the surface of AFM nanoneedle &
delivered. But low through put and limited cargo.

7. Arrays of vertical nanoprobes – silicon nanowires- developed.
Plasmid DNA, siRNA, IgGs, Qdots, rhodamine- labelled peptide –
coated on silicon wires.
Cell lines and primary cell – cultured on vertical silicon nanowires.
Other physical approaches…. Electroporation
For Large cargos- bacteria , enzyme , antibodies and nanoparticles ,
Biophotonic laser- assisted surgery tool (BLAST) system – deliver large
elements into 1,00,000 cell /min.
In addition to physical approaches… Endocytosis- by engulfing.

8. Intracellular biopsy refers to the operation of Extracting
intracellular structures or organelles from within the cell
Eg. Mitochondria. Extracted and sequenced.
This enables the quantitative assessment of
mitochondrial mutation rate in single cell

9. TRANSLOCATION
Moving object inside the cell – cause minimal damage to cell and its activity.
Endogenous organelles and foreign untethered materials – used to
translocate. Manipulated remotely via optical trapping and magnetic
tweezers.
Optical trapping- focused laser beam – produce – attractive or repulsive
force. They physically hold and move micro/nano object.
Magnetic tweezer – controls magnetic nanoparticals.
Properties for magnetic tweezer..
Cellular elasticity and cytoplasmic viscosity.
Magnetic force applied only to internalized magnetic partical.
Either move or manipulate ..(chromatin and phagosome)
Magnetic force – piconewton to several nanonewtons.

12. WHAT IS NANOSENSOR…..
Sensors operate on the scale of atoms and molecules
Smaller size, lower weight, modest power requirements
Data storage systems
Biological, chemical, or physical sensory points used to convey
information about nanoparticles to the macroscopic world.
A Nanosensor is a sensor created on the atomic scale that obtains
information about nanoparticles and translates it to a scale we can
easily analyze.

13. Nanosensors – chemical or mechanical sensors – used to detect
presence of chemical species and nanoparticle / monitor physical
parameter (temperature)- on the nanoscale.
Nano refers – object measured in nanometer
Size at nanoscale:
An ant is about 5 000 000 nanometers long
One single bacterium is about 1000 nanometers long
One sheet of paper is about 100 000 nanometer thick
A human hand – 100 000 000 nanometers long
The water molecule is about 1,5 nanometers
A single strand of hair is about 80 000 up to 100 000 nanometers wide
1 nanometer per second is the rate at which fingernails grow

15. Why nanosensor…
Smaller
Require less power to run
Greater sensitivity
Better specificity

16. CHALLENGES
Reducing the cost of materials and devices
Improving reliability
Packaging the devices into useful products

17. EXAMPLES OF NANOSENSING
APPLICATION..
Detect airborne chemicals: excess levels of carbon monoxide
Detect virus and bacteria: to carbon nanotube, antibody is bond..
When match is attached then it measures.
Measure the temperature of living cells: nanothermometers inserted
into separate cell.
Measure temperature of nanofluids : heat management is a growing
issue.

18. ADVANTAGE
Better signal
Faster response
Increased data density
More accurate data
Less impact on the phenomenon being measured

19. THANK YOU!!!!