Non-destructive Technologies for Plant Health Diagnosis

Abstract

As global population grows rapidly, global food supply is increasingly under strain. This is exacerbated by climate change and declining soil quality due to years of excessive fertilizer, pesticide and agrichemical usage. Sustainable agricultural practices need to be put in place to minimize destruction to the environment while at the same time, optimize crop growth and productivity. To do so, farmers will need to embrace precision agriculture, using novel sensors and analytical tools to guide their farm management decisions. In recent years, non-destructive or minimally invasive sensors for plant metabolites have emerged as important analytical tools for monitoring of plant signaling pathways and plant response to external conditions that are indicative of overall plant health in real-time. This will allow precise application of fertilizers and synthetic plant growth regulators to maximize growth, as well as timely intervention to minimize yield loss from plant stress. In this mini-review, we highlight in vivo electrochemical sensors and optical nanosensors capable of detecting important endogenous metabolites within the plant, together with sensors that detect surface metabolites by probing the plant surface electrophysiology changes and air-borne volatile metabolites. The advantages and limitations of each kind of sensing tool are discussed with respect to their potential for application in high-tech future farms.

Raman spectroscopy in crop quality assessment: focusing on sensing secondary metabolites: a review

“…In general, the most common options of laser wavelengths in Raman measurement are 532 nm (green) and 633 nm (red), and 785 nm (near-infrared). Since the Raman scattering efficiency is proportional to 1/λ ex [ 4 ], a clear Raman spectrum with relatively intense peaks is produced by equipping a shorter wavelength as shown in Fig. 2A .…”

“…There are quite a number of representative studies presenting that adjusting light intensity and wavelength [ 2 ] or cultivation temperatures [ 3 ] affects the accumulation of secondary metabolites, especially antioxidants known for their biological activities, including anti-inflammatory, anti-oxidant, and anti-carcinogenic effects. This consequently leads to a demand for the development of various powerful technologies to assess plant conditions in real-time [ 4 ]. The conventional analytical procedures for evaluating crop quality, such as high-performance liquid chromatography (HPLC), gas chromatography (CG), or those combined with mass spectrometry (MS), as well as biological analysis based on enzyme-linked immunological assays, are time-consuming and necessitate complex and labor-intensive pretreatment [ 5–7 ].…”

Review—Recent Advances in Nanosensors for Precision Agriculture

“…10 The high sensitivity, specificity, stability and accuracy followed by the rapid response rate make nanosensors more useful for smart agriculture over conventional sensors due to their higher surface to volume ratio, and faster electron transfer kinetics. [11][12][13][14][15][16][17][18][19][20][21] With the technological revolution being made in nanotechnology, nanosensors have been developed to play a significant role in the advancement of agriculture. The application of nanosensors can revolutionize agriculture by providing rapid updates in the growing environment, such as air flow, air humidity, carbon dioxide, temperature, pH and dissolved oxygen in water.…”

Nanosensor Applications in Plant Science

“…A number of reviews have been published on the application of nanosensors in the plant sciences. Unlike this review, they are generally focused on the specific applications of nanotechnology, e.g., to agriculture [ 19 , 20 , 21 ] or plant pathogen detection [ 22 , 23 ], specific areas, e.g., in planta nanosensors [ 24 ], or more specific forms of nanomaterial, e.g., carbon nanotubes [ 25 ]. This review focuses on nanosensors and their applications in living plants, plant cells, plant tissues, and plant organelles.…”