This New Device Measures Glow Emitted By Plants To Check Their Health. New Study Explains How

Did you know that healthy plants emit a red light that cannot be seen with the naked eye? Now, researchers from York University in Ontario have developed a new instrument that can measure the light in a laboratory or a field to check if a plant is healthy. The study describing the findings was recently published in the journal Biosensors. 

The glow from healthy plants is a delayed fluorescence that comes from light absorbed from the Sun, and is related to photosynthetic activity and health of the plant. After absorbing a flash of light, plants emit this glow. 

In a statement released by York University, Ozzy Mermut, one of the authors on the paper, said one can tell how healthy the plant is by the robustness of the red light they emit. She added that the weaker the light gets, the less healthy the plant is. 

Mermut also said that one cannot always tell the health of the plant just by looking at it, because, often, the plant will look green and healthy until they test it. 

How the new device works

The new, highly sensitive and portable biosensor engineered by Mermut and York University Professor William Pietro, the first author on the paper, can measure this glow. Pietro said they developed a device that can capture low intensity light emission from plants. 

According to the study, the device is a solid-state silicon photomultiplier-enabled portable delayed fluorescence photon counting device. A silicon photomultiplier is a device designed for the detection of extremely weak light, down to a single photon. 

How the device will benefit the world

The device can be deployed remotely, enabling the device to help measure the health and sustainability of plants, especially those stressed by carbon-dioxide emissions, greenhouse gases and extreme weather events. The device also assesses the impacts of industrialisation. 

Since the device is the size of a briefcase, not only can it be used in a lab, but can also be carried from one place to another.

Pietro said the results from the device can tell researchers about the reaction of plants under various environmental conditions, including drought, heat and cold shock stress or after floods. The device does this in a powerful new way that enables researchers to study the phenomenon of plant emission directly in the field, and is so sensitive that it can count individual photons emitted from plants. 

According to the statement, this would not have been possible even a few years ago, because the technology was too large, complicated and expensive. The study team aims to use the device to study the impacts of climate change over time on plants. 

The researchers also hope to mount the device on a drone so that it can fly over rainforests, conservation areas and agricultural fields. This will help farmers address food security to gauge plant health.