Phenol-based styrylpyrylium dyes for trace water detection via chromogenic and fluorogenic responses

A novel fluorescent indicator‐based fluorene derivative for rapid and visual trace water sensing

“…Several fluorescent detection systems have been developed for water assay by combining traditional sensing mechanisms, including intramolecular charge transfer (ICT) [7], photo-induced electron transfer (PET) [8], excimer and exciplex [9], aggregation-induced emission (AIE) [10], excited-state intramolecular proton transfer (ESIPT) [11], hydrolysis reactions of Schiff bases [12] and ferrocene derivatives [13], and hydration of aldehydes [14], with various materials such as small molecular organic fluorescent probes [15], metalorganic frameworks (MOFs) [16], carbon dots (CDs) [17], polymers [18,19], and copper nanoclusters [20]. Despite the considerable achievements observed in this domain owing to their exceptional sensitivity and accuracy, the majority of existing fluorescent techniques are plagued by issues such as diminished fluorescence signal output [20][21][22][23][24][25], limited portability, demanding processing protocols, and susceptibility to interference from environmental factors like pH [26] and polarity [27,28].…”

Anthracene-(aminomethyl)phenylboronic acid ester-immobilized glass substrates as fluorescent sensing materials based on photo-induced electron transfer for detection and visualization of water

“…In recent years, there has been increasing interest in the development of fluorescent sensors and their functional materials, including polymers, membranes, and sensorimmobilized substrates for detecting and visualizing water in solids, solutions, and gas or on material surfaces, because such fluorescent sensing systems for water are crucial to environmental and quality control monitoring, industrial processes, food inspection and so on. Actually, some kinds of organic fluorescent sensors for water, based on ICT (intramolecular charge transfer), [25][26][27][28][29][30][31][32][33] ESIPT (excited state intramolecular proton transfer), [34][35][36][37] PET (photo-induced electron transfer), [38][39][40][41][42][43][44][45][46][47][48][49][50][51][52] or solvatochromism have been developed which exhibit photophysical changes in wavelength, intensity, and lifetime of fluorescence emission depending on the water content. Hence, over the last decade and a half, we continued to make much effort to design and develop PET-type fluorescent sensors for water in solvents.…”

“…When water is added to the solution of OF-2, the nitrogen atom of the amino moiety is protonated or strongly interacts with water molecules to form the PET inactive (fluorescent) species OF-2W, and as a result, a drastic enhancement of the fluorescence emission is observed due to the suppression of PET. Indeed, the detection limit (DL) and quantitation limit (QL) of OF-2 for water in acetonitrile are, respectively, 0.009 wt% and 0.026 wt%, which are equivalent or superior to those of fluorescence quenching systems (turn-off) based on the reported ICT-type [25][26][27][28][29][30][31][32][33] and ESIPT-type [34][35][36][37] fluorescent sensors. Thus, it was demonstrated that the PET method based on the fluorescence enhancement (turn-on) system makes it possible to visualize, detect, and determine a trace amount of water in solvents.…”

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

“…From the literature, it is found that up to date, only a few colorimetric sensors are reported for moisture detection, most of which are off-the-shelf. [29,39,40] Thus, on these premises in the current article we have designed and synthesized benzothiazole substituted azo derivative, 2AMBP, following diazotization and condensation reactions. The adopted reaction is a simple, cost-effective using easily available reactants.…”

“…Moreover, exploring vivid applications like moisture detection in raw foods, drugs, and leaves can expand the applicability of the designed and synthesized molecule. From the literature, it is found that up to date, only a few colorimetric sensors are reported for moisture detection, most of which are off‐the‐shelf [29,39,40] …”