Interviewing Dr. Pedro B. Coto, one the pioneers of the BioLED technology

If you go to IKEA to buy a lamp for your cozy apartment, you will see that many of them contain LEDs (ligh-emitting diodes) instead of old bulbs. Even bulbs are made of LEDs nowadays. I have the opportunity to talk to one of the experts in BioLED technology (1). Dr. Pedro B. Coto has helped to develop a technology that may someday become a sustainable alternative form of illumination. At the interface of quantum chemistry, material science and biotechnology he explains me how this fascinating invention works. We had a beer together the crystallographer Jose Antonio Cuesta-Seijo (research scientist at the Carlsberg Research Laboratory) who also gave some advice in this project, and I ask Dr.Pedro B. Coto a few questions.

Darío Vázquez: As biotechnologist I may struggle to understand the foundations of the LED technology. So can you explain in simple words what a LED is? What are the physics behind?

Dr. Pedro B. Coto: A LED is a small device consisting of two bands made of special metals or materials called semiconductors (they have a higher resistance to electric current than normal metal wires for example). One of the semiconductor bands has an excess of electrons and the other a deficiency (holes). When electric current flows through these materials, electrons jump from the high electron band to the holes. This difference in energy is emitted as light. Depending on the composition mix of this semiconductor a different color is emitted as light giving rise to most of the colors.

LED vs Bioled

Conceptual scheme of a traditional LED vs  a BioLED

Darío Vázquez: What is the main problem of the current LED technology? What is then the need to invest in research for new alternatives?

Dr. Pedro B. Coto: Semiconductors are the core commodity of LEDs, but face different disadvantages. One of these is how to produce cheap white LEDs, which involves the use of materials (YAG:Ce or phosphor) that are scarce in the Earth crust and not environmentally friendly and therefore non sustainable in the long term. This is one of the aspects that can be solved using fluorescent proteins.


“Producing white light is challenging with the current LED technology”


Darío Vázquez: Fluorescence is essentially light emitted by a substance that has absorbed light or electromagnetic radiation. The golden standard of fluorescent proteins is called GFP (Green Fluorescence Protein) which emits green light in response to UV light excitation and was discovered in the jelly fish Aquorea Victoria. Your team has put three different fluorescence proteins together (Green, Red and Blue) to achieve white light. Could we then consider your BioLED technology as more sustainable alternative to regular LEDs? Why?

Dr. Pedro B. Coto: Our BioLED does not completely replace common LEDs but substitutes one of the components of the LED making it more sustainable and environmentally friendly. It consists of a special rubber formulated to avoid killing fluorescent proteins and allow them to stay stable for a long time (to the surprise of the scientific community). This rubber is extremely easy to prepare and does not generate any significant pollutant side products. What’s more, this technology has the potential of becoming much lower in cost than the regular LED.


“BioLEDs represent a more environmentally friendly and sustainable light source alternative”

Fluorescent proteins

For left to right, two images of fluorescence proteins separate. On the right the BioLED consisting of a mix of the three fluorescent proteins.

Darío Vázquez: I imagine there are other technologies competing to solve the same problem. What’s the current state-of-the-art of these technologies and the main advantage of yours?

Dr. Pedro B. Coto: You are right; there are other technologies such as other organic compounds that replace semiconductor materials found in LEDs. Some inorganic materials can also withstand thermal degradation that proteins do not. However, the existing organic compounds found interesting release too much energy as heat or degrade much easier than fluorescent proteins in our rubber substrate. Unlike the scientific community thought, fluorescence proteins are more efficient emitting light and more stable than these organic compounds.

Darío Vázquez: Do you have a plan to commercialize or patent such a fascinating invention? Will we see IKEA lamps with you BioLEDs mounted on them?

Dr. Pedro B. Coto: We have already filed the patent. We are currently optimizing several aspects of the BioLED device to push it as close as possible to a commercial stage. This would make it more appealing for potential companies interested in acquiring the technology. There are still many years ahead of us to see lamps with our BioLEDs but we are definitely committed to work for a more sustainable approach.


“The technology still has to be optimized until we see BioLED lamps in the market”


Darío Vázquez: I wanted ask you; why did you end up established in Germany? Given your impressive track record I would have expected you to be able to go back to Spain.

Dr. Pedro B. Coto: I started with several external stays during my PhD and postdocs in Paris, Sweden and Germany, followed by several postdoctoral grants. In between I have made two attempts to go back to Spain but I was unsuccessful in the different applications I attempted so I decided to stay en Germany because of the possibilities I found here to continue with my research lines.

Darío Vázquez: As you may have noticed associations of Spanish researchers abroad are flourishing around the world. The main goals of these are not only to help Spanish researchers to establish in the host country but most importantly boost scientific collaborations between hosting institutions and Spanish institutions. These could create opportunities for mutual funding to increase scientific competitiveness. As scientist do you think that our role might be decisive in the future?

Dr. Pedro B. Coto: Absolutely this can help boost international collaborations. However, it is not convenient to limit collaborations to Spanish researchers. We have to make an effort to integrate in the society of our host country and show taxpayers why it is worth to establish bridges between countries.

Group pictureThe group that developed the BioLED. Michael Weber, Uwe Sonnewald, Marlene Proeschel, Pedro B. Coto, Rubén D. Costa (Group leader), Martina Lang


  1. Weber MD, Niklaus L, Proschel M, Coto PB, Sonnewald U, Costa RD. 2015. Bioinspired Hybrid White Light-Emitting Diodes. Adv Mater 27:5493-5498.


Dr. Pedro B. Coto

Dr. Ruben Costa