Quantum Dots: Biotechnology Applications
Quantum dots can be used in various ways, one of which is to record vaccinations as almost invisible tattoos, these tattoos can then be scanned by a modified smartphone camera which detects the near-infrared light emitted by the quantum dots. Dr. Matthew Booth presented on this topic as part of his seminar on applications of quantum dots in biotechnology.
Quantum dots are semiconductor nanocrystals with a diameter of only a few nanometers. To explain exactly how a quantum dot can emit light, you can use a potential well model. An electron is free to move within the material, but there is a potential that confines it to a limited region. One model of this is a particle in a one-dimensional box as a quantum dot is so small in size that an electron in the material has quantised states.
Quantum dots absorb photons at higher energies (shorter wavelengths) to move into excited states. As it relaxes back to its ground state, it emits a photon of a specific wavelength. The size of the quantum dot determines the wavelength of the photon. As it contains quantum dots that emit light in the near-infrared range, the vaccine tattoo can be scanned by a smartphone camera with the correct equipment.
Quantum dots are very promising for medical applications because of their use in improving our ability to record vaccinations, which would be helpful in developing regions where vaccination rates are low and vaccine storage and recording is limited. As quantum dots can emit the same wavelengths of light after many absorption-emission cycles, they are more useful than organic dyes which stop emitting light after repeated exposure to UV radiation.
46422
This piece offers a nice explanation of how quantum dots absorb and emit photons, and how this relates to the potential well model and particle in a box problem. It also mentions how they can be used in recording vaccinations.
31842
Great detail and good use of the content from Dr Booth’s talk