Near-Infrared Fluorescent Probes with Large Stokes Shifts for Sensing Zn(II) Ions in Living Cells

Abstract

We report two new near-infrared fluorescent probes based on Rhodol counterpart fluorophore platforms functionalized with dipicolylamine Zn(II)-binding groups. The combinations of the pendant amines and fluorophores provide the probes with an effective three-nitrogen-atom and one-oxygen-atom binding motif. The fluorescent probes with large Stokes shifts offer sensitive and selective florescent responses to Zn(II) ions over other metal ions, allowing a reversible monitoring of Zn(II) concentration changes in living cells, and detecting intracellular Zn(II) ions released from intracellular metalloproteins.

A hexa-quinoline basedC3-symmetric chemosensor for dual sensing of zinc(ii) and PPi in an aqueous mediumviachelation induced “OFF–ON–OFF” emission

“…Zinc is the second most abundant transition metal occurring in the human body and plays diverse roles in several vital biological processes like cellular metabolism, neurotransmission, etc. [1][2][3][4][5][6][7][8][9][10][11] In everyday life, zinc is found in various foods, automobiles, sunscreens, cosmetics and surgical tools etc. It exists mostly as Zn 2+ in the body as well as in nature.…”

“…12 However, misregulation of Zn 2+ causes several diseases like Alzheimer's, epilepsy, infantile diarrhea, prostate cancer, etc. [1][2][3][4][5][6][7][8][9][10][11][13][14][15][16][17] On the other hand, pyrophosphate (PPi), which is produced during ATP hydrolysis, is a crucial anion for normal cell functioning, e.g., it is involved in DNA polymerase catalyzed DNA replication and real time DNA sequencing. [18][19][20][21][22][23][24][25][26][27][28][29] So, it is highly desirable to explore efficient methods to detect and monitor Zn 2+ and PPi in environmental as well as in biological samples.…”

“…For this purpose, fluorescence sensors have drawn a lot of attention from the chemistry community because of their various advantages like high sensitivity, simplicity, and versatile instrumentation. [1][2][3][4][5]12,[20][21][22][23][24][25][26] Here, it has to be mentioned that, due to the almost similar electronic properties of Cd 2+ and Zn 2+ , it is indeed difficult to develop a selective chemosensor for Zn 2+ without the interference of Cd 2+ . [30][31][32][33][34] Though an ample number of fluorescence sensors for Zn 2+ have been reported based on di-2-picolylamine (DPA), 9,10,[15][16][17][35][36][37][38][39][40] quinoline, 1,8,10,15,35,41-46 bipyridyl 1,47 etc.…”

“…and their derivatives, involving photoinduced electron transfer (PET), intermolecular charge transfer (ICT) and chelation induced enhanced fluorescence (CHEF) mechanisms, [1][2][3]8,12,21,48 the number of sensors capable of selectively sensing Zn 2+ in an aqueous buffer through a wide range of pH values is still limited. [4][5][6]41,[49][50][51] In this context, among different types of fluorescent zinc sensors, quinoline substituted ligands have been paid much attention due to their well-known chelating property towards soft metals as well as suitable spectral behavior. 1,41,[42][43][44][45][46] It has also been observed that, in some cases, an increase in the number of quinoline units in the binding arm improves the sensitivity.…”

Searching for new borondifluoride β -diketonate complexes with enhanced absorption/emission properties using ab initio tools

“…The design of fluorescent dyes is a subject of paramount importance for the development of molecular probes for biomedical imaging and emitting solid-state materials for display technologies [1][2][3][4][5][6][7][8] . Among the numerous families of organic luminescent molecules, boron dipyrromethene (BODIPY) derivatives (Scheme 1) are the most widely used owing to their outstanding photophysical properties and very large emission quantum yields [9][10][11][12][13] .…”