Micro And Nanosensors

Question 1

What is a biosensor

Answer 1

Measure chemical information (metabolites, cytokines…)

Can convert this information into electrical signals

Question 2

How are different signals generated and transduced?

Answer 2

Electrical:
Electrons ➡️ redox➡️ measurement eg. Diabetic glucose sensor
Ions➡️ activity and conductivity
Optical:
Photons➡️ fluorescence, scattering
Mechanical:
Mass change➡️ mechanical measurement of electrical changes

Question 3

How can biosensors be used to detect antibodies

Answer 3

Nano cantilevers
Ligands immobilised on nano levers
Antibiotic binds and distorts lever
There is a deflection
Produces signal

Question 4

How do nanowires work

Answer 4

When there is binding to wire

Change in current and voltage of nanowire

Question 5

How have nano sensors been used in next generation sequencing

Answer 5

Amplify DNA
Beads will carry copy of single sequence
Beads added to microplate wells
Record the pH change in each well when 4dNTPs added sequentially
When base incorporated get voltage change

Question 6

What is single molecule DNA sequencing

Answer 6

DNA polymerase immobilised on waveguide

Fluorescence from each base will be detected

Question 7

Whats another example of DNA sequencing using nano sensors

Answer 7

Nanopore

Question 8

Other examples of nanobiosensors

Answer 8

Quantum dots - fluorescent biosensor

PEBBLES - fluoresce when glucose is present. Measure glucose levels