A press release came out this week, touting an exciting new paper in Nanotechnology Letters in which enzymes from fireflies were combined with nanorods to producing easily tunable light. The release does a pretty good job of explaining the basic science involved in the work (I’ll get to that later), but I found it most notable for the forced way in which it scrapes for importance and meaning to an experiment that is already hugely important. Why, in particular, is chemistry (and its closely-related cousin, materials science) so frequently bound to “real-world” applications, while no one questions the applications of sequencing a genome or detecting the Higgs boson?
But first, why was this nanorod/enzyme science so interesting? It sits at an incredibly ripe threshold between nanotechnology and biotechnology that, from the viewpoint of many scientists, is key to developing a wide array of new technologies. The proteins developed by species over millions of years of evolution are often incredibly efficient at doing challenging chemistry. In particular, when it comes to using light to do chemistry (or vice-versa), we’re still struggling reaching the same levels of efficiency that natural selection has produced.
The problem is that with this efficiency comes specialization. An enzyme might only break down a narrow subset of molecules, or (as in the case of this firefly enzyme and luciferin) only produce a narrow range of light colors. When it comes to flexibility and adaptability, modern chemistry and materials science has nature beat by a mile. We can currently design nanostructures that will produce light at any color we desire.
So the key, then, is to combine the efficiency of natural solutions with the flexibility of modern chemistry. This is what the authors of the Nano Let paper have accomplished. The firefly enzyme very efficiently breaks down luciferin (the most sinisterly-named molecule of all time) to produce an excitation that would normally become light. Instead, that excitation is transferred to the nanorod by a process called BRET (biochemical resonance energy transfer). The nanorod will emits that energy at a color that is based on the size of the rod. Scientists have a pairing perfect to emit easily controlled light from the chemistry done by a highly efficient protein.
This work is exciting, clever, and flexible. So why does a press release need to describe, “Christmas lights that don’t use electricity?” (Lights based on this technology would still need luciferin to run; I personally find plugging Christmas lights in to be far more efficient than feeding them.) It’s often the case that the scientists themselves never envision the most exciting implications of their own science. In fields like biology, it would seem that good press practices have familiarized the general public with the importance of burgeoning fields like genomics. On the opposite end of the spectrum, in fields like physics, the general public isn’t expected to fully appreciate a discovery; instead, grand ideas about the nature of reality itself and the origin of the universe serve to excite the public.
But I realize now that chemistry is in the troubled middle child of the natural sciences. The world as it is could not exist without developments in solid-state chemistry and plastics and medicinal chemistry, but the results of these efforts are so wide-ranging and so ubiquitous that it sometimes seems to me that the wonder has been lost. The solution to this, of course, is to stop emphasizing the trivial and banal applications of exciting chemistry and materials science.