Moisture-Sensitive Ratiometric Color-Changing Response: a Useful Tool for Precision Farming

Abstract

Anthra­[1,2-d]­imidazole-6,11-dione-based charge transfer probes have been developed for the detection of water impurities in a wide range of laboratory-used organic solvents. The deprotonated (anionic) forms of the probe molecules, obtained upon addition of basic anions such as fluoride, demonstrate a ratiometric color-changing response (blue to yellow in presence of F– and red to yellow with CN– ion) even in the presence of a trace amount of moisture (detection limit: 0.008 wt %). Considering their high sensitivity and “naked-eye” response, the anionic receptors are utilized for the quantification of moisture level or water impurity in a wide range of real-life samples, such as building raw materials, packaged food items, soil, plant leaves, and so on. Determination of the moisture level of plant leaves or soil samples is particularly important for precision farming as it helps the farmers to schedule the irrigation events. Finally, low-cost, reusable, and optical kit-based dye-coated paper strips were developed for rapid, on-location detection as well as quantification purposes. Since such a sustainable approach does not involve any sophisticated instruments or complex sample preparation steps, the general public with little knowledge of science or technology will be able to use it without much difficulty.

Development of pH-Responsive Polymeric Pesticides as Supramolecular Inclusion Complexes for Targeted Control of B. cinerea in Precision Agriculture

“…The excessive use of pesticides has led to severe environmental contamination and compromised food security. As a result, researchers have increasingly focused on developing new low-toxicity pesticides and improving methods for detecting pesticide residues. − In recent years, nanopesticides greatly improved the utilization efficiency of pesticides, and enabled the pesticide delivery system more “intelligent”. − In particular, there is a growing interest in the development of stimulus-responsive controlled release systems (SRCRSs) for precise pesticide delivery. , Controlled-release nanocarriers are generally composed of stimuli-responsive triggers and nanomaterials, which are used to encapsulate or physically wrap active ingredients (AIs). , Normally, the carriers exist in the forms of nanocapsules, nanospheres, nanomicelles, nanogels, nanofibers, nanoemulsions structures, and so on . Nanopesticides hold promise for the development of environmentally friendly and safe botanicals, but their limitations, include low drug loading efficiency, poor stability, uncontrolled release kinetics, and insufficient drug activity, pose challenges to widespread application …”

Fluoride Induced Dual Mode Moisture Detection in Organic Solvents, Food, and Agricultural Materials using Benzothiazole Based Azo Dye Sensor

“…However, slow response time, less sensitivity, irreversibility and complicated synthetic route are more common drawbacks of the present-day sensory systems. [23][24][25] The reported colorimetric sensors like Anthra[1,2d]imidazole-6,11-dione-based charge transfer probes, [26] quinizarin, [27] dye encapsulated zeolite AlPO4-5, [28] Sudan-III and Alizarin Red S [29] are based on mechanisms of photoinduced electron transfer (PET), [30] intramolecular charge transfer (ICT), [31] water-induced decomplexation, [32] solvatochromism [33] and proton transfer. [34] All the mentioned molecules and mechanisms of operation of these sensors needs multistep synthesis and tedious purification protocols of the products and some of them are off the shelf dyes.…”