Harnessing the power of plants

Harnessing the power of plants

February 22, 2017

February 22, 2017

Science fiction writers have often described a world where the biological and electronic realms operate in unison to achieve the extraordinary.

The successful integration of living matter and electronic components could unlock many new possibilities in biomedicine, environmental sensing, and energy applications.

One fascinating natural system that researchers are trying to learn more about is photosynthesis. The process—carried out by plants, algae and some bacteria—holds the secret to producing power from simple sunlight. If modern science could fully understand and harness it, the economic, social and climate impacts would be groundbreaking.

Attaching electrical mechanisms to biological components  without damaging the natural functions however, has proven to be significant hurdle for researchers. The process becomes even more complicated when the goal is to use an electrical mechanism to alter chemistry within the cell.

Despite the complexity of this task, a team of researchers at ASU’s Biodesign Institute and the School of Molecular Sciences has successfully integrated the photosynthetic reaction center from the purple bacterium Rhodobacter sphaeroides with an electrode. They described their approach in a recent article in the Journal ACS Applied Materials & Interfaces.

The result is a sort of micro-laboratory, able to mimic some of the vital life processes used by plants to convert sunlight into useable energy.

Anne-Marie Carey, corresponding author for the paper and a researcher in the Biodesign Center for Innovations in Medicine said the ability to create this type of a controllable reaction center opens up a new realm of exciting possibilities for researchers.

The team’s biohybrid approach, which creates a kind of artificial leaf, “...will apply not only to artificial photosynthesis strategies but also to a wide variety of bio-electronic and bio-optical interfaces for use in devices and processes applicable to biomedicine, environmental sensing, and photocatalysis and green chemistry,” said Carey. The strategy involves melding electrodes with key molecular components at the heart of photosynthesis.

Other scientists share Carey’s excitement about creating such a synthetic reaction center. Similar techniques could be used in many different lines of research.

For some time, people have sought to use the types of reactions found in nature for industrial purposes, said associate professor Anne Jones from the School of Molecular Sciences at ASU. If the chemistry that occurs naturally in living things could be harnessed, a new world of opportunities would open in energy technology and biosensing.

One of the most talked about applications of this concept, in an industrial context, is in solar panel systems. When the sun goes down, solar panels can’t generate electricity anymore, so we store some of that power in batteries. The problem is that the energy density of modern batteries is too low for some applications, meaning that solar energy can’t be used to power everything. (Energy density refers to the amount of energy that can be stored in a given volume.)

The energy density that you can store in molecules using chemistry however, is much higher. This could be a way to use electrical energy collected by solar panels to generate a fuel molecule for example, which could have much better energy density than current battery technology.

Another possible application for such a system is as a biosensor. If you want to sense a molecule, you need some kind of output to monitor it. The nice thing about this type of electrochemistry is that it can be used to detect very small quantities of whatever a researcher is monitoring. These next generation biosensors have the potential to make a significant impact in the clinic when diagnosing patients or recommending treatment.

This paper has demonstrated a conduit between the natural and synthetic worlds, a method for making connections that weren’t previously available.


Written by: Gavin Maxwell