Flexible Aggregation-Induced Emission-Active Hydrogel for On-Site Monitoring of Pesticide Degradation

Abstract

Benefiting from the stimuli-responsive property and powerful loading capacity, functionalized hydrogels are favorable for the fabrication of sensing devices. Herein, we design aggregation-induced emission (AIE)-active hydrogel discs by embedding gold nanoclusters@zeolite-like imidazole framework (AuNCs@ZIF) composites in double-network hydrogels to build a sensitive pesticide biosensor. The hydrogel discs integrate an AIE effect of AuNCs, a stimuli-responsive property of ZIF, and a porous network structure of the hydrogel, which enhances the sensing sensitivity via boosting the stable fluorescent signal and antifouling performance. In conjunction with a homemade device, the fluorescence images of hydrogel discs could be transduced into data information for accurate quantification of chlorpyrifos pesticide with a detection limit of 0.2 ng/mL. The dynamic degradation of chlorpyrifos in Chinese cabbage is demonstrated to confirm the practical application of hydrogel discs. Such AIE-active hydrogel discs could be a plant health sensor for the on-site quantification of pesticide residues on crops, holding great promise for precision agriculture.

In Situ Fabrication of Photoluminescent Hydrogen-Bonded Organic Framework-Functionalized Ca (II) Hydrogel Film for the Tetracyclines Visual Sensor and Information Security

“…However, according to time-resolved spectral measurements in Figure C,D, the fluorescence lifetime of the HOF hydrogel film (2.54 ns) was higher than that of MA-IPA (1.87 ns) (Table S1). These results indicate that the free movement of MA-IPA in hydrogels is restricted, suppressing the nonradiative relaxation path and further improving the fluorescence lifetime . Notably, MA-IPA and HOF hydrogel film exhibited ultralong RTP with the phosphorescence lifetime of 1.60 s (Figure E,F), indicating that the phosphorescence lifetime of MA-IPA loaded on SA hydrogel was not significantly affected by intermolecular ET.…”

Recent advances in aggregation-induced emission (AIE)-based chemosensors for the detection of organic small molecules

“…39a). 305 AChE catalyses the hydrolysis of acetylthiocholine (ATCh) into thiocholine (TCh), which promotes the collapse of AuNCs@ZIF, causing AuNCs to fall out of the framework and effectively quenching the fluorescence at 578 nm. The inhibition of AChE-catalysed TCh production by chlorpyrifos, however, prevents this, and the corresponding fluorescence changes can be transduced by the device into data information for accurate quantification of the OP.…”

A Review of Functional Hydrogels for Flexible Chemical Sensors

“…Other applications of flexible chemical sensors for detecting ions (e.g., Na + , K + , Hg 2+ , Cu 2+ ), [ 6b,96a,128 ] alcohol, [ 69 ] DNA, [ 129 ] pesticide, [ 130 ] astringency perception, [ 131 ] and living cells [ 132 ] have also been developed with functional hydrogels. For example, a skin‐like hydrogel elastomer‐based electrochemical sensor has been fabricated by employing PAAm/calcium alginate hydrogels as a substrate to achieve conformal contact with skin, while thermoplastic polyurethane (TPU) film as an interlayer to bridge the hydrogels and conductive ink.…”

“…The device exhibited excellent linearity over the concentration range of ≈0.5–10 000 ng mL −1 of chlorpyrifos and a low LOD of 0.2 ng mL −1 . [ 130 ]…”