This research presentation focuses on self assembly of viruses with functionalized semiconductor nanoparticles (quantum dots) as their cores. These virus-like particles can be used as probes for cellular imaging and specific targeting. In order to find the suitable candidate to serve as the core of the virus in terms of stability and toxicity, photostability experiments have been carried out on micelle-coated, streptavidin-coated, thiol-coated and PEG(poly ethylene glycol)-thiol quantum dots. Experimental evidence indicates that prolonged irradiation results in the partial precipitation of the quantum dots in all cases except PEG-thiol coating. Partial desorption of the hydrophilic surface coating is believed to be at the origin of the photo-induced precipitation. Moreover, the photostability of micelle-coated quantum dots is independent of the thickness of the micelle. Streptavidin coated quantum dots exhibited a similar optical behavior like micelle coated dots unlike thiol coated quantum dots which displayed a faster decay in stability. The only stable coating observed was that of PEG-thiol.

In consistency with the photostability results, only PEG-thiol coated quantum dots proved successful in getting incorporated inside BMV (brome mosaic virus) capsids while the other functionalized dots failed. This is an initial attempt towards making artificial luminescent viruses. These findings need to be looked upon further to transform the virus-like particle into a viable optical probe. The figure below shows TEM image reconstruction of quantum dot encapsulated virus like particle.