A water‐soluble fluorescent pH probe based on perylene dyes and its application to cell imaging

Abstract

A fluorescent pH probe, N,N'-bi( l-phenylalanine amine)-perylene-3,4;9,10-dicarboxylic diimide (PDCDA) was synthesized and used for pH sensing in living cells. A significant fluorescence intensity change was observed over a pH range from 7.0 to 4.0. Electrostatic potential maps (MEP) suggested that the electronic repulsion between PDCDAs was increased by the high negative electrostatic potential which resulted in a high water solubility of PDCDA. PDCDA was successfully applied as a high-performance fluorochrome for living HeLa cell imaging. The results demonstrate that the probe PDCDA is a good candidate for monitoring pH fluctuations in living cells with good water solubility, low cytotoxicity, high fluorescence quantum yield and photostability.

Synthesis and Characterization of Superhydrophobic, Self-cleaning NIR-reflective Silica Nanoparticles

“…Perylene derivatives have been identified as fluorophores with high fluorescence quantum yield, good photostability6 and a high molar extinction coefficient (10 5  M −1  cm −1 for isolated perylene bisimide chromophores)7 owing to a planar and highly conjugated structures. Furthermore, the high reflectance in the NIR region of the electromagnetic spectrum allows the incorporation of thermal insulating properties into materials8.…”

Perylene Diimide-Based Fluorescent and Colorimetric Sensors for Environmental Detection

“…The colorimetric sensing thus observed is due to the electronic change of the cyclobutene skeleton, which in turn results in dramatic electronic change in PDI core through direct conjugation between the cyclobutene and PDI. This pH sensing mechanism is reminiscent of the commonly used pH indicators [32][33][34][35][36][37][38]. Other molecular design strategies (some uncommon) have also been brought into this field.…”

“…Sensors for transition metal ions from IB group (Cu 2+ ), IIB group (Zn 2+ , Cd 2+ , Hg 2+ ) and VIIIB group (Fe 3+ , Ni 2+ , Pd 2+ ), and alkaline earth metals IIA group (Ba 2+ ), and boron family IIIA group (Al 3+ ) have been studied in both aqueous and binary water-organic solutions . Besides metal ions, sensors for other cations like proton (pH detection) have also been developed, particularly for the bio-relevant systems [32][33][34][35][36][37][38]. Similarly, sensors have also been studied for the non-metal anions such as F − , CN − , ClO 4 − and PO 4 − ions, etc.…”

“…In view of the strong tendency of aggregation PDIs molecules through stacking interactions between the π-conjugated skeletons in aqueous media, most studies of PDI-based chemosensors are in organic-aqueous composite systems to maintain the molecular dispersion of PDI sensors [7,8,[15][16][17][18][19][20][22][23][24][25][26][27][29][30][31]. There still remain challenges to study the sensing performances in pure water solutions [10,21,[32][33][34][35][36][37][38][39]. Most importantly, the fluorescence variations of PDIs are pH-dependent and thus the corresponding sensors should be operated under well-controlled pH of the working solution, for which addition of buffer reagent like (2-[4-(2-hydroxyethyl)-1-piperazinyl]-ethanesulfonic acid) (HEPES) is usually necessary [15,16,20].…”

“…As seen above, solution pH plays crucial role in affecting the assembly-disassembly and PET-controlled fluorescence sensing of PDIs. Especially for the detection of non-metal anions, most of the PDI-based fluorescent sensors used are relied on pH dependent (H + variation) PET process [32][33][34][35][36][37][38]. In these cases, water-solubility is a primary requirement for design and synthesis of PDIs sensor molecules.…”