Rhodamine-modified upconversion nanophosphors for ratiometric detection of phosgene

Ratiometric upconversion luminescence nanoprobes from construction to sensing, imaging, and phototherapeutics

“…For convenient mastering, previous studies on ratiometric UCL nanoprobes are appropriately classified and regularly arranged based on specific targets and characters, including temperature (Table 1), 28–84 pH (Table 2), 85–99 inorganic anions, cations, free radicals (Table 3), 100–126 gases, small common molecules, biological small molecules and biomacromolecules (Table 4). 127–162 For a better understanding of construction strategies, the following sections provide principle construction methods and ratiometric dual-signal modes of ratiometric UCL nanoprobes by discussing the state-of-the-art related studies.…”

“…Particularly, FRET (LRET) has been largely involved during the sensing process of ratiometric UCL nanoprobes toward the effective detection of specific targets. 86,88,89,91,93,98,101,105,111,117,118,121,123,126–131,133,135,136,141–143,146,149–152,154,156–159 When UCL emission spectrum of a phosphor (from nanoprobe systems) as the energy donor can efficiently (larger-area) overlap with the absorption spectrum of another component (from nanoprobe systems or modified derivatives in combination with targets) as the energy receptor, NIR light excitation of phosphor donor will induce the receptor to produce luminescence, and meanwhile, UCL intensity of the donor decreases. Generally, the efficiency of FRET or LRET is closely associated with the spatial distance between donors and receptors.…”

“…Ratiometric UCL nanoprobe systems have exhibited great prospects for efficient sensing and detection of various molecules in previous studies, such as gases (CO, 127 NO, 128–130 and O 2 195 ), small molecules (H 2 O 2 , 131–135 N 2 H 2 , 136 HNO, 149 HOCl, 111 and phosgene 158 ), biomolecules (glutathione, 135 uric acid, 137 ascorbic acid, 138,139 cysteine, 140 arginine, 143 spermine, 144 and enzyme substrate 197 ), biomacromolecules (miRNA, 156 cytochrome c , 155 myoglobin, 198 flavin mononucleotide, 201 receptor protein, 201 alkaline phosphatase, 200 thymidine kinase 1, 152 metalloproteinases, 153,154 caspase-3, 159 phospholipase D, 160 and extracellular cancer-specific biomarker PTK-7 157 ), and drug or other molecules (doxorubicin, 141,142 camptothecin, 142 diethyl chlorophosphite, 150,151 dimethoate, 150 furfural, 145 melamine, 163 amaranth, 148 Rose Bengal, 146 perfluorooctane sulfonate, 147 and explosives 199 ) (Table 4). Most of the nanoprobe systems consist of upconverting luminescent materials (lanthanide-doped UCNPs and derivatives) that generally undergo functional modifications with organic molecules, inorganic materials, and organic–inorganic composites to form the core@shell, hollow, porous, complex, hybrid, mixture, assembly, engineering, and multifunctional complicated structures.…”

“…Most of the nanoprobe systems consist of upconverting luminescent materials (lanthanide-doped UCNPs and derivatives) that generally undergo functional modifications with organic molecules, inorganic materials, and organic–inorganic composites to form the core@shell, hollow, porous, complex, hybrid, mixture, assembly, engineering, and multifunctional complicated structures. 127–163,195–201 Major molecule sensing mechanisms are target-induced occurrence or suppression of the LRET (FRET) process, IFE, PET, etc . The sensing process often refers to the interactions of targets with nanoprobe systems, referring to the target-sensitive luminescence, absorption-caused quenching, aggregation-induced quenching, structural decomposition and recombination, target-responsive drug release, spiro-ring closure, opening reactions, surface molecularly imprinted structure regulation, backbone/peptide/enzymatic cleavage, enzyme cascade signal amplification, etc .…”

Sensitized Lanthanide Photoluminescence Based Sensors–a Review

“…Development of sensors with higher selectivity for analytes, higher dynamic ranges and lower limits of detection (LOD) is an active area of research. Conventional solution‐based sensing methods suffer from many limitations in practice [5,6] . In this regard, fluorescent hydrogels have increasingly attracted attention due to their hydrophilic, swellable, biocompatible and eco‐friendly nature [7] .…”