Creation of Protein Encapsulated Quantum Dots as Biocompatible Fluorescent Labels

In order to track the movement of, or find the location of specific proteins in living cells, it is necessary to label them using either a fluorescent, chemiluminescent or radioactive label. In this research we propose the construction of a new biocompatible hybrid material made of the protein apoferritin and a semiconductor nanocrystal (quantum dot) that has better fluorescence properties than currently used fluorescent dyes. This could be used as a tool in the study of both healthy and diseased cells to identify fundamental biochemical processes.

We propose to construct a new protein encapsulated-quantum dot (QD) hybrid system and realise a more efficient fluorescent label than the currently available organic fluorescent dyes. The encapsulation of the quantum dot with in the protein shell of apoferritin will provide a means of stabilising the dot luminescence, controlling the size of the dot and hence its emission wavelength, and improving the dot solubility in water. The protein exterior of the QD-apoferritin hybrid would facilitate the conjugation to other organic molecules such as antibodies, oligosaccharides or cell-targeting peptides. An increase in the specificity of conjugation reactions will be achieved by the introduction of azide bearing un-natural amino acids that are suitable for click chemistry. This will be achieved with the assistance of scientists at the Molecular Foundry, Berkeley. Dr Turyanska, the scientist hopping disciplines has significant experience in the synthesis and characterisation of quantum dots. She will gain training in the biochemical and molecular biological techniques necessary to integrate the quantum dots into protein cages such as apoferritin, and in the characterisation techniques required to investigate these novel systems.