infocus #56 December 2019 Robust Measurements

DOI: 10.22443/rms.inf.1.175

Luminescent markers for monitoring biological processes is a well-developed, although imperfect science. Luminescence, in this case, is actually photoluminescence from an organic semiconducting electronic structure, where a photo-excited electron recombines with a photo-generated hole, specifically from an exciton in the pi/pi* orbitals.

Organic dyes are the usual material when cell-imaging studies (or associated diagnostic procedures) are required. Recent advances in material science have opened up new avenues to biologically-relevant luminescent materials, usually considered the domain of organic chemists. These new materials exploit the robust optical properties required for display applications and, when combined with other functionalities provided by such materials, represent the next generation of imaging technologies.

The emergence of chemically-accessible nanotechnologies over the last 20 years has opened up a new family of biologically-active materials. The interaction of gold nanoparticles with DNA might be considered one of the first examples of the crossover between solid-state sciences with biology, two disciplines that traditionally have not overlapped. The comparative sizes of, for example, proteins and nanoparticles however make the merging of such technologies obvious. These initial developments inspired further work into new multidisciplinary arenas and one of the most successful might be considered the development of new imaging agents for biology, with semiconductor quantum dots (QDs) notably emerging from typical solid-state applications (such as display devices and solar cells) to become commercially available cellular imaging agents.