Plant Stress Sensor Detects Crop Issues in Under a Minute

This wearable sensor measures hydrogen peroxide levels — a key indicator of stress — in soybean and tobacco plant leaves. Credit: Adapted from ACS Sensors 2025, DOI: 10.1021/acssensors.4c02645

While visual inspection and farmer intuition have long served as the cornerstone of crop management, modern agriculture is increasingly challenged by the need for more precise and efficient methods of detecting plant stress. Environmental pressures, resource limitations, and global food demands highlight the inadequacy of traditional techniques in identifying early signs of stress. In response to this growing need, researchers from the American Chemical Society have unveiled a novel solution: a wearable patch for plants capable of detecting stress in under a minute.

What limitations do conventional detection methods face, how does this new sensor work, and what potential does it hold for the future of sustainable agriculture?

Understanding the Challenges of Plant Stress Detection

For centuries, farmers have relied on their senses and experience to determine the health of their crops. As far back as the ancient Egyptians, it is recorded that they would use their own 5 senses to try to determine the quality of their crops. They would touch the leaves of their plants, check for moisture and texture, and smell the plants to determine if they had any signs of disease. If a plant showed signs of disease, it would be removed and destroyed to prevent the disease from spreading to other plants. This method of detecting plant health was adequate for small-scale farming in ancient Egypt, but as agriculture progressed, it became less practical. 

As the world moved into the industrial age, agricultural practices evolved rapidly. New farming techniques were developed, and machinery was introduced to help with the physical labour involved with farming. However, despite all the tools and techniques available, the detection of plant stress was (and still is) reliant on human experience and intuition.

This reliance on human sensing not only results in lost crops, but also wasted water, fertilisers, and other resources. The inability to identify the cause of a stress can make it difficult to develop a plan to address the issue, and this can result in a loss of income for the farmer. 

However, the challenges faced by farmers are not limited to the quality and quantity of their crops. Plant stress also has a major impact on the environment, and this has a knock-on effect on the wider food chain. The environmental impact of plant stress is a result of the changes that a plant undergoes when it is under stress. For example, a plant that is suffering from drought will change the chemical composition of its leaves to help retain water, and this can result in the release of harmful volatile compounds into the air. 

Finally, the impact of plant stress extends to the wider public. The food chain is long, and each stage of the chain has an impact on the final product that is consumed. Therefore, if the quality and quantity of a crop is reduced, then the final product will also be affected. This can result in a wide range of problems, including food poisoning, contamination, and a reduced quality of life for those who consume the food.

American Researchers Develop Wearable Patch for Plants to Detect Stress in Under a Minute

In a significant breakthrough for the agricultural sector, researchers from the American Chemical Society have developed a wearable patch that can detect stress in plants in under a minute. The innovative sensor, which is attached to the underside of plant leaves, measures hydrogen peroxide, which is a key marker of stress in plants.

The sensor, which is described in a recent paper published in ACS Sensors, is a significant improvement over current methods for detecting hydrogen in plants. Unlike traditional methods, which involve removing plant parts and using complex external detectors to measure fluorescence changes, the new sensor is a simple and cost-effective solution that can be attached to the underside of leaves. The sensor is also reusable, with the researchers able to use the patch up to nine times before it loses its sharpness.

Innovative Design and Sensor Mechanics

Notably, the research team utilised a chitosan-based hydrogel that facilitates the electrochemical detection of hydrogen peroxide via microscopic needles. These microneedles, positioned on a flexible backing, penetrate the leaf surface just enough to obtain readings without damaging the tissue. According to the team, this structure allowed for accurate, repeatable measurements of hydrogen peroxide in less than one minute, enhancing the responsiveness of early stress detection in crops.

The sensor can detect hydrogen peroxide in plant leaves at significantly lower levels compared to other sensors on the market. This enhanced sensitivity enables earlier identification of stress, giving growers a critical head start in preventing disease and damage. In addition, the device delivers real-time data, essential for making timely and informed decisions about crop management.

Field Testing and Agricultural Impact

According to the lead researcher Liang Dong, the patch provides reliable hydrogen peroxide data for less than a dollar per test, underscoring its affordability for wide-scale agricultural use. The patch’s efficiency was further demonstrated when tested on both soybean and tobacco leaves infected with Pseudomonas syringae, a known bacterial pathogen, where it exhibited a strong correlation between hydrogen peroxide levels and plant stress response.

The researchers tested the sensor on two types of plants, soybean and tobacco, and were able to detect stress in both plants. The sensor was able to detect higher levels of hydrogen peroxide in stressed plants compared to healthy plants, which confirmed that the sensor was able to detect stress accurately.

Furthermore, conventional detection techniques often struggle with chlorophyll interference during fluorescence analysis. In contrast, this wearable sensor eliminates such complications, offering direct electrical readouts unaffected by plant pigmentation. This attribute significantly increases the practical utility of the device in varied lighting and environmental conditions, an important consideration for commercial farming operations.

The development of the sensor is a significant breakthrough for the agriculture industry, which is often plagued by disease and pests. By detecting stress in plants early, growers can take action to prevent disease from spreading and reduce the amount of pesticides used. This not only improves crop yields but also helps to reduce the environmental impact of farming.

Beyond disease detection, early stress identification supports broader sustainability goals. With climate change intensifying drought and temperature stress on crops, the ability to pinpoint biochemical distress signals—such as hydrogen peroxide—could inform adaptive interventions. This capability enhances resilience across farming systems while reducing dependence on chemical treatments and irrigation resources.

Expanding the Sensor’s Role

The wearable patch developed by the researchers is a significant step forward in the field of plant stress detection, but there are many ways that the sensor could be expanded to provide even more benefits to growers. 

One potential development for the sensor would be the integration of wireless data transfer capabilities, allowing for real-time monitoring of plant health from remote locations. This could be particularly beneficial for large-scale commercial farms where data needs to be collected and analysed on a massive scale. The use of wireless data transfer would also allow for the sensor to be used in a wide range of different applications, including precision agriculture and smart farming systems.

Another potential development for the sensor is the integration of AI-based analysis capabilities. While the sensor is able to identify hydrogen peroxide in plant tissues, it is not able to identify the cause of the stress. This means that growers would need to analyse the data from the sensor and make decisions based on their own experience and knowledge. The integration of AI-based analysis would allow the sensor to identify the cause of stress in plants, providing growers with a more accurate diagnosis and allowing for more targeted treatments. This could also help to reduce the amount of pesticides and fertilisers used in farming, as well as reduce the environmental impact of agricultural practices.

Regardless, what the researchers have developed is truly an excellent piece of engineering, and if it can be scaled up, could very well be the solution that helps to minimise the environmental impact of farming, while simultaneously help to better feed the world.

The research team has acknowledged plans to refine the patch technology further, with a focus on increasing reusability and extending the sensor’s lifecycle beyond nine applications. Future iterations could potentially include modular diagnostic features to detect a wider range of plant biomarkers, broadening the tool’s applicability across diverse crop species and stressors.