Nanoscaled Fluorescent Films and Layers for Detection of Environmental Pollutants

Abstract

Hazardous gas and ion pollutants are the most serious environmental problems around the world. It is of great importance to develop devices for easy detection of these hazardous substances. Fluorescence technology with high resolution and operational simplicity has attracted a lot of attention in recent years. Organic fluorescent dyes absorb/emit lights within a broad wavelength range, which is suitable for various demands. Chromophores, such as perylene, cyanine dyes, spiropyran, and so on, are widely studied as fluorescent probes for gases and ions. The dyes could respond to external stimuli through structural changes of the conjugated chromophore itself or the attached functional groups, leading to detectable spectral changes. Organic dyes are incorporated into nanoscaled films and layers, which are portable and durable for effective sensing in complex environments. In this chapter, preparation and application of fluorescent films and layers (FFL) for gaseous/ionic detection are reviewed. We discuss the response mechanism of fluorescent dyes, the fabrication of nanoscaled FFL, and some examples of FFL for the detection of gas and ion pollutants.

Sulfur- and Nitrogen-Containing Porous Donor–Acceptor Polymers as Real-Time Optical and Chemical Sensors

“…[17][18] In this study, we make use of four key-properties of our conjugated, porous D-A polymersnamely, (1) their strong, covalent backbones, (2) their intrinsic Lewis acidity and basicity, (3) their permanently accessible pore channels to gaseous guest molecules, and (4) their optical bandgaps in the visible part of the spectrum -and we use them as optical and electronic sensors and switches that are triggered by volatile acid vapors and re-set by gaseous ammonia. While colorimetric chemical probes are known from molecular systems in solutions, [19][20] or work on the basis of chemical transformations, [21][22][23] the here-presented study shows one of the first instances of amorphous porous conjugated polymers used as fully-reversible, colorimetric chemical probes.…”

Sulfur- and Nitrogen-Containing Porous Donor-Acceptor Polymers as Real-Time Optical and Chemical Sensors

“…[17][18] In this study, we make use of four key-properties of our conjugated, porous D-A polymersnamely, (1) their strong, covalent backbones, (2) their intrinsic Lewis acidity and basicity, (3) their permanently accessible pore channels to gaseous guest molecules, and (4) their optical bandgaps in the visible part of the spectrum -and we use them as optical and electronic sensors and switches that are triggered by volatile acid vapors and re-set by gaseous ammonia. While colorimetric chemical probes are known from molecular systems in solutions, [19][20] or work on the basis of chemical transformations, [21][22][23] the here-presented study shows one of the first instances of amorphous porous conjugated polymers used as fully-reversible, colorimetric chemical probes. Recently, we showed, that triazine-containing COFs, made by the same principle, can be also exploited as acid/base chemosensors, thus, highlighting the significance of our approach in view of making multifunctional smart materials.…”