Innovative technical solutions for futuristic smart agriculture
Sensor technology for a wide range of agricultural task have been developed but more innovative sensor based technical solutions are needed for smart intelligent farming system in future due to new challenges the world facing today. Agriculture requires technical solutions for increasing production while lessening environmental impact by reducing the application of agro-chemicals and increasing the use of environmentally friendly management practices. Both biotic and abiotic stresses lead to a massive loss in crop yield, leading to decrease in agricultural production worldwide. The loss of agricultural products can be minimized by adopting modern technology such as smart phones with nanosensors to detect crop stress at an early stage. Smart and precision agriculture are emerging areas where sensors and electronic devices can play an important role for improving crop productivity by monitoring crop health status in real-time. Sensors are customized using various properties of nanomaterials to combat various challenges of contemporary techniques. Both biotic and abiotic plant stresses and nutritional deficiency can be monitored in real-time to report crop health status for precise and efficient use of resources. There are thousands of reports about the recent advances in sensors technology and their applications in futuristic smart intelligent agriculture.
Sensor is a term used for any probe, reporter, indicator, molecular sensor or sensing device. A nanosensor has typically three main modules: a transducer, a receptor and a detector with a digital output. The target molecule connects with the receptor and the biological detecting component identifies a biological molecule through a reaction. The transducer converts changes to a signal quantified by the detector. The nanosensor has the advantages such as high specificity and sensitivity, rapid response, condensed size, portability, and real-time analysis. Nanosensor technology has been improved the specificity and sensitivity, performance, and quality by employing nanocomposites such as nanofilm, quantum dot, or gold nanoparticles. There are various types of sensors such as electrochemical nanosensors, optical sensors, piezoelectric, metal or metalloid nanoparticles-based, quantum dots, genetically encoded nanosensors, surface-enhanced Raman scattering nanosensors, array-based sensors, wearable sensors etc.
Various types of sensors have been reported for detection and monitoring plant signal molecules and metabolic contents related with biotic and abiotic stresses.With the help of sensors-based innovative solutions, plant stresses such as biotic, abiotic and nutritional deficiency can be monitored using various electronic devices including smart phones and cameras. Nanosensors communicate with and actuate electronic devices for improving crop productivity by optimization and automation of water and agrochemical allocation. Thus, these nanosensors will be able report crop health status for precise and efficient use of resources. This technology is highly beneficial for detecting the onset of biotic and abiotic stress at an early stage. Nanotechnology has distinct advantages to engineer smart plant sensors because engineered nanomaterials can be embedded in plants for monitoring signaling molecules by near-infrared cameras in real camera. To fabricate such nanobiosensors, existing tools and technologies such as microfluidics, plasmonic nanosensors, fluorescence, chemiluminescence, quartz crystal microbalance, molecular imprinted polymers, advanced electrochemical measurements coupled with customized nanomaterials and nano-composites are used. The real-time crop monitoring technology ensures high agriculturally produce with the precise use of costly agrochemicals. It also helps minimize the loss of limited resources such as water or nutrients. The advancement in sensor-based smart and intelligent technology can reduce the impact of biotic and abiotic stress on agricultural produce and enhance the optimal use of limited resources. Innovative smart-sensors technology can enable communication and actuation of electronic devices for optimizing crop growth and yield in response to resource scarcity or stresses.
These plant signaling molecules have the potential to report the onset of crop health changes in real-time by detecting resources deficit or plant stresses. Detection of analytes in the living plant is optically difficult due to photosynthetic pigments and thick tissues. Hence, nanosensors are more suitable for in vivo studies of cellular signaling due to the ease of embedding them into plant tissues. There are several key signaling molecules such as sugars including sucrose and glucose, calcium ions, reactive oxygen species, molecular oxygen, nitric oxide, hydrogen peroxide, volatile organic compounds, adenosine triphosphate, strigolactones, dopamine, phytohormones including abscisic acid, jasmonic acid, methyl salicylate and ethylene, which have been reported to be monitored by engineered nanomaterials and genetically encoded based nanosensors. These plant signaling molecules have the potential to report the onset of crop health changes in real-time by detecting resource deficit or plant stress. Hence, these chemical traits help to diagnose specific biological or environmental stress. Detection of plant disease, metabolic parameters within cellular microenvironment is extremely important for monitoring crop growth and productivity. Nanobiosensors have already established their presence for diagnosis various parameters of clinical, environmental and food quality control. But nanobiosensors for plant disease diagnosis are limited. This review is an attempt to throw spotlight on recent development in this direction. These mainly include use of gold nanoparticles, magnetic nanoparticles, grapheme and its variants, QDs or their combinations for detection of bacterial, fungal, and viral pathogens for plant disease detection using both optical and electrochemical measurements. These nanobiosensors demonstrated detection of various parameters such as carbohydrate, nutrients, proteins, receptors, phytohormones, miRNA. Use of transcriptomic biosensor and genetic encoded biosensors is another arena that has shown enormous potential for studding in vivo microenvironment of plant dynamics.
Nanotechnology innovation is running fast in many field of life science, smart application in agricultural science still lag behind, particularly delivery of agrochemicals and biosensing. Nanomaterials have been used as sensing material to develop nanosensors in the field of agriculture and food sector. Although the use of nanosensors in agriculture is at an initial stage, but nanomaterials are reported to use as tools for detection and quantification of plant metabolic flux, residual of pesticides in food and viral, bacterial and fungal pathogens. Nanomaterials-based nanobiosensors are very promising because of rapid detection and precise quantification of bacteria a, virus and fungi in plants. Various types of nanosensors have been used in plants and reviewed including fluorescence resonance energy transfer (FRET)-based nanosensors, carbon-based electrochemical nanosensors, nanowires nanosensors, plasmonic nanosensors and antibody nanosensors.
Although biosensors have been used in human and animals for several decades to address a broad number of applications, their use in plant system is emerging, particularly in precision agriculture and urban farming. Through a better understanding of plant molecular biology and signaling pathways, innovative therapeutic uses of existing molecule within plants have been discovered. The installation of nanosensors or nanoscale wireless nanosensors in living plants is currently applied to enable the real-time monitoring and early detection of potential problems related to biochemistry and metabolism. Intracellular sensors for metabolic precursors signaling ligands and nutrients may help elucidate the complex roles of these molecules in plant system.
Agriculture requires technical solutions for increasing production while reducing environmental impact by reducing the application of agrochemicals and increasing the use of environmentally friendly management practices. A benefit of this is the reduction of production costs. Sensor technologies produce tools to achieve the above mentioned goals. The explosive technological advances and development in recent years have facilitated the attainment of some of these objectives removing many barriers for their implementation, including the reservation expressed by farmers. Precision agriculture is an emerging area where sensor-based technologies play an important role. Farmers, researchers and technical manufactures are combining their efforts to find efficient solutions, improvements in production and reductions in cost.
Various area of agricultural system where sensors technology based on the requirement of farmers, according to the farming operations include crop health status determination; crop phenotyping, germination, emergence and determination of different growth stages of crops; non-destructive soil sensing; the detection, recognition and mapping of nutrient stress in crops; automated detection and mapping of crop enemies and threat situation of weed, fungi, virus and insects; detection of microorganisms and pest management; detection and identification of crops, and weeds and their control; volatile compounds detection, electronic noses and tongues; yields estimation and prediction; the detection of fruits and their quality; airborne sensor (UAV); hyperspectral, multispectral, fluorescence and thermal sensing based on optical sensor technology; robot navigation, localization and mapping and environmental awareness; robotic applications in crop management; positioning, navigation and obstacles detection; traceability systems in the field by using new technologies e.g. RFID, barcode, GPS, Zigbee; network in agriculture, wearable sensors, the Internet of Things (IoT); low energy, disposable, energy harvesting sensors; deep learning from sensor data in agriculture.
In coming years, various metallic and carbon based nanomaterials will be used for plant diagnostics. Various novel techniques and unique feature/flexibility of nanomaterials and opportunities to nano-tune various properties will soon realize fabrication of Next-Gen Nanobiosensors that will provide additional features of portability, real-time detection, accuracy, and simultaneous analysis of different analytes in a single device. Sensors will communicate with and actuate electronic devices for agricultural automation. Achievements made so far suggest that nanobiosensors are the pioneers for the future disease diagnosis devices for monitoring crop health status in real-time that offer unlimited opportunities to be tapped. Considering the importance of monitoring crop health status in real-time, researchers should be encouraged to divert their attention focusing on research in the field of nanobiosensors technologies using innovative nanomaterials and novel biomarkers for monitoring crop health status in real-time.
Reference:
- Prof. Dr. Dimitrios Moshou, www.mdpi.com
- Huaimin Li et al. Sensors 2020, 20(10), 2894
- https://doi.org/10.3390/s20102894 – 20 May 2020
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