Polymer films doped with fluorescent sensor for moisture and water droplet based on photo-induced electron transfer

Abstract

Polymer films doped with a photo-induced electron transfer (PET)-type fluorescent sensor exhibit green excimer emission in the PET active state, but blue monomer emission in the PET inactive state upon exposure to moisture.

Tetraphenylethene–anthracene-based fluorescence emission sensor for the detection of water with photo-induced electron transfer and aggregation-induced emission characteristics

“…2b and c). Therefore, these facts indicate that the fluorescence properties of EN-1 in both the aggregate state and the solid state were not derived from the anthracene dimer or excimer emission 17,18 but were due to the AIE characteristics associated with the aggregate formation of EN-1(H 2 O)-A in both the PET-inactive and RIR states (Fig. 1c).…”

“…[1][2][3][4][5][6][7][8][9][10][11] Moreover, fluorescent sensors for water have the potential to be functional materials, which would allow the visualization as well as detection and quantification of moisture or water droplets on material surfaces, and have promise to be applied to environmental, biomedical, and quality control monitoring systems. [12][13][14][15][16][17][18] Indeed, various kinds of organic fluorescent sensors for the determination of the water content in solvents based on their intramolecular charge transfer (ICT), [19][20][21][22][23][24][25][26][27][28][29] excited state intramolecular proton transfer (ESIPT), [30][31][32][33] photoinduced electron transfer (PET) [34][35][36][37][38][39][40][41] or solvatofluorochromic properties [42][43][44][45][46]…”

“…1–11 Moreover, fluorescent sensors for water have the potential to be functional materials, which would allow the visualization as well as detection and quantification of moisture or water droplets on material surfaces, and have promise to be applied to environmental, biomedical, and quality control monitoring systems. 12–18 Indeed, various kinds of organic fluorescent sensors for the determination of the water content in solvents based on their intramolecular charge transfer (ICT), 19–29 excited state intramolecular proton transfer (ESIPT), 30–33 photo-induced electron transfer (PET) 34–41 or solvatofluorochromic properties 42–47 have been designed and developed. The effects of ICT, PET, and ESIPT on the fluorescent sensing properties for the detection of water were investigated based on the intermolecular interactions of the fluorescent sensors with water molecules, which demonstrated that ICT-, PET-, and ESIPT-based fluorescent sensors were suitable for the detection and quantification of a trace amount of water (below 1–10 wt% in almost every case) in solvents.…”

“…Furthermore, to develop fluorescent polymeric materials for the visualization and detection of water, we carried out the preparation of various types of polymer films (polystyrene, poly(4-vinylphenol), polyvinyl alcohol, and polyethylene glycol) doped with OF-2 . 17 It was found that the OF-2 -doped polymer films exhibited a reversible switching of the fluorescent colour between the green excimer emission in the PET-active state under a drying process and the blue monomer emission in the PET-inactive state upon exposure to moisture or water droplets. Thus, we demonstrated that the fluorescence enhancement (turn-on) system of the PET-based fluorescent sensor was suitable for the visualization as well as detection and quantification of a trace amount of water in samples and on material surfaces.…”

Fluorescent polymer films based on photo-induced electron transfer for visualizing water

“…In recent years, concern has been raised about the development of fluorescent sensors and their functional materials such as polymer films and sensor-immobilized membranes for visualizing water in solutions, solids, and gas or on material surfaces, from the viewpoint of their potential applications to environmental and quality control monitoring systems and industry, as well as fundamental study in photochemistry, analytical chemistry, and photophysics. 1–23 Several investigations have been conducted on the design and synthesis of organic fluorescent sensors and polymers for the detection of water based on ICT (intramolecular charge transfer), 24–34 ESIPT (excited state intramolecular proton transfer), 35–38 PET (photo-induced electron transfer), 39–46 or solvatochromism 47–52 and the elucidation of the optical sensing properties based on changes in wavelength, intensity, and lifetime of fluorescence emission depending on the water content. It was demonstrated that most of ICT- and ESIP-type fluorescent sensors and fluorescent conjugated polymers exhibited attenuation of the fluorescence emission, that is, fluorescence quenching (turn-off) systems with the increase in water content in solvents, and were suitable for the detection and quantification of a trace amount of water (below 1–10 wt% in almost every case) in solvents.…”