Since their development in the 1980s, fluorescent quantumdot semiconductor nanoparticles have increasingly replaced traditional organic fluorophores in applications such as biomolecule tagging, tissue imaging, and ion sensing. [1][2][3][4][5][6] Interest in fluorescent quantum dots (QDs) derives from their broad absorption, narrow emission, intense brightness, and good photostability relative to organic dyes.[7] Surprisingly, despite the large and diverse set of fluorescence-based sensing systems for glucose, [8][9][10][11] no methods for glucose detection that utilize inherently fluorescent QDs have been reported.[12] Previously, we demonstrated a very general twocomponent glucose-sensing system in which glucose modulates the ability of a boronic acid substituted viologen quencher/receptor to quench the fluorescence of anionic organic dyes. [13][14][15] Signal modulation occurs when glucose binds to the boronic acid receptor moiety, which at pH 7.4 exists in its trigonal neutral form in the absence of glucose. [16] Formation of the more-acidic glucose boronate ester shifts the acid-base equilibrium of the boronic acid towards its anionic tetrahedral "-ate" form. These electronic and/or steric changes, which have been confirmed with 11 B NMR spectroscopy, cause a decrease in the quenching interaction between viologen and fluorophore and result in an increase in fluorescence. This two-component approach to glucose sensing allows considerable flexibility in choosing the quencher/ receptor and fluorophore components depending on the particular requirements of the sensing application. For example, fluorophore components may be selected to provide any one of a range of desired excitation or emission wavelengths, whereas a particular quencher/receptor may be chosen for reasons of its monosaccharide-binding selectivity. Herein we show that some of the advantages of QDs can be realized in our two-component system to sense changes in glucose concentration in aqueous solution. The putative mechanism for glucose sensing with quantum dots and

Sweetness and light: A fluorescent thin‐film hydrogel that contains a covalently bound boronic‐acid‐functional quencher (Q) and a fluorescent dye (F; see Figure) continuously senses glucose under physiological conditions through binding of the sugar (S) to a labeled receptor (R).

The fluorescence sensing of several monosaccharides using boronic acid-substituted viologen quenchers in combination with the fluorescent dye pyranine (HPTS) is reported. In this two-component sensing system, fluorescence quenching by the viologen is modulated by monosaccharides to provide a fluorescence signal. A series of viologen quenchers with different charges were prepared and tested for their ability both to quench the fluorescence of HPTS and to sense changes in glucose concentration in aqueous solution at pH 7.4. Both quenching efficiency and sugar sensing were found to be strongly dependent upon viologen charge. The molar ratio between HPTS and each of the viologen quenchers was varied in order to obtain an optimal ratio that provided a fairly linear fluorescence signal across a physiological glucose concentration range. Both the quenching and sugar sensing results are explained by electrostatic interaction between dye and quencher.

Herein, we demonstrate how judicious selection of the donor decorating a central multi-resonant thermally activated delayed fluorescence (MR-TADF) core based on DiKTa can lead to very high-performance OLEDs. By decorating the DiKTa core with triphenylamine (TPA) and diphenylamine (DPA), 3TPA-DiKTa and 3DPA-DiKTa exhibit bright, narrowband green and red emission in doped films, respectively. The OLEDs based on these emitters showed record-high performance for this family of emitters with maximum external quantum efficiencies (EQE max ) of 30.8 % for 3TPA-DiKTa at λ EL of 551 nm and 16.7 % for 3DPA-DiKTa at λ EL = 613 nm. The efficiency roll-off in the OLEDs was improved significantly by using 4CzIPN as an assistant dopant in hyperfluorescence (HF) devices. The outstanding device performance has been attributed to preferential horizontal orientation of the transition dipole moments of 3TPA-DiKTa and 3DPA-DiKTa.

In an ongoing program to synthesize a glucose sensing polymer that could be used for real time glucose monitoring in vivo, we have been exploring the use of boronic acid functional viologens as glucose responsive quenchers for fluorescent dyes. The present study focuses on the effect of ionic interactions between pyranine or its various sulfonamide derivatives and the viologen quenchers. Dyes bearing anionic groups were quenched more efficiently when compared to dyes with nonionic substituents. The anionic dyes in conjunction with the cationic quenchers exhibited a broader range of glucose response both in solution and when immobilized in a hydrogel. The interaction of glucose with the sensing components was similar whether they are soluble or immobilized.