Determining Essential Requirements for Fluorophore Selection in Various Fluorescence Applications Taking Advantage of Diverse Structure–Fluorescence Information of Chromone Derivatives

Abstract

Herein, we report our work exploring the essential requirements for fluorophore selection during the development of various fluorescence applications. We assembled a library of chromone-derived fluorophores with diverse structure−fluorescence properties, which allowed us to choose the fluorophore pairs with similar structures but differing fluorescence properties and compared the performance of the selected fluorophore pairs in three types of commonly used fluorescence applications. We found that the selection standard of a suitable fluorophore is variable depending on the application. (1) In fluorescence imaging, fluorophores with strong and constant fluorescence under various conditions, such as a large pH range, are preferred. Notably, (2) in the detection of bioactive species, fluorophores with relatively lower fluorescence quantum yield favor the detection sensitivity. Furthermore, (3) in enzymatic assays employing fluorescence, the key parameter is the binding affinity between the fluorophore and the enzyme.

Insights Into the Detection Selectivity of Redox and Non-redox Based Probes for the Superoxide Anion Using Coumarin and Chromone as the Fluorophores

“…The synthesis of probes R1–R3 is depicted in Scheme 1 . Compounds 1 , 2 , and 3 are coumarin derivatives and were prepared as described previously ( Wang et al, 2020 ; Chen et al, 2021 ). 1 , 2 , and 3 were reduced to probes R1 – R3 via hydrogenation, employing 10% Pd/C.…”

“…The synthetic routes of compounds Ra , Rb , and Rc are outlined in Scheme 2 . Three chromones 4 , 5 , and 6 were prepared as previously described ( Chen et al, 2021 ). For the reduction, we used LiAlH 4 to reduce the chromones to yield the desired chromanones under a low temperature.…”

“…Various ROS were also prepared as literature in 0.1 M phosphate buffer, 0.15 M NaCl, pH 7.4, or anhydrous DMSO ( Wang et al, 2020 ; Chen et al, 2021 ). Each probe was dissolved in these ROS solutions at the final concentration of 10 μM.…”

“…Coumarin is a known fluorophore and has been frequently used in various studies to a high level of success (Cao et al, 2019). Additionally, chromone derivatives have also been found to exhibit a range of interesting fluorescent properties (Miao et al, 2015;Chen et al, 2021). Series 1 (R1, R2, R3) and series 2 (Ra, Rb, Rc) were designed as redox Doura et al, 2012;Wang et al, 2020).…”

Advances in the site-selective C-5, C-3 and C-2 functionalization of chromones via sp2 C–H activation

“…Apart from their biological applications, they show promising uorescent activity, and hence can be used as sensors in detecting various metal ions and in bioimaging. [27][28][29][30][31][32][33][34] The promising biological and photophysical activities of chromones make them a valid scaffold of interest among chemists.…”