Fluorescent probes for organelle-targeted bioactive species imaging

Abstract

The dynamic fluctuations of bioactive species in living cells are associated with numerous physiological and pathological phenomena. The emergence of organelle-targeted fluorescent probes has significantly facilitated our understanding on the biological functions of these species. This review describes the design, applications, challenges and potential directions of organelle-targeted bioactive species probes.

BODIPY‐Based Fluorescent Probes for Biothiols

“…Therefore, exploiting powerful approaches for the detection of analytes of interest in diverse organelles is beneficial for the better understanding of multifarious physiological and pathological processes and improving the diagnosis and treatment of different diseases. Over the past decade, significant efforts have been devoted to the design and development of organelle‐targeting fluorescent probes for accurate detecting of various bioactive analytes of interest …”

Development of a Neutral Diketopyrrolopyrrole Phosphine Oxide for the Selective Bioimaging of Mitochondria at the Nanomolar Level

“…In short, these lipophilic cationic structures carry the risk of reducing the mitochondria membrane potential (MMP), which is associated to detrimental effects in their critical working function. Further, probe leakage through the membrane can also be attributed to a reduction in the MMP, hence decreasing the efficiency of the staining agents . In response to the latter, the development of neutral fluorescent probes that maintain selective targeting of mitochondria and alleviate those concerns would represent major innovations and is therefore highly warranted .…”

“…Whilst access to the mitochondria intermembrane space is relatively straightforward, facilitated by means of large protein‐based pores in the outer membrane, the inner membrane is characterised by a much more restricted permeability, loaded with proteins that play a role in electron transport and ATP synthesis processes. Transport across and onto the mitochondrial matrix can only occur aided by specific membrane transport proteins . The latter has motivated the development of peptide‐based mitochondrion staining agents whereby specific protein‐ligand type interactions are favoured, which could foster the rational development of novel non‐peptidic alternatives for mitochondrial staining species …”

“…Transport across and onto the mitochondrial matrix can only occur aided by specific membrane transport proteins . The latter has motivated the development of peptide‐based mitochondrion staining agents whereby specific protein‐ligand type interactions are favoured, which could foster the rational development of novel non‐peptidic alternatives for mitochondrial staining species …”

“…[11,[14][15][16][17] This large potential distinguishes it from other subcellular organelles and has inspired the successful development of optically active probes that exploit it selectively.T hus, systems containing delocalised lipophilic cations (DLCs)such as triphenylphosphonium or pyridinium cation, which are presenti nt he majority of mitochondria targetingp robes to date andw hich are believed to improve membrane transport and increasem itochondria probe accumulation, have been widely used to ensure selectivity towards this subcellular compartment attracted by the negative potentialo ft he membrane, whilst maintaining an otherwise non-polar framework in most cases. [6][7][8]18] In this regard, a number of organic dyes such as fluorescein, [19,20] coumarin [21,22] and rhodamine [23,24] have been utilised as the fluorescent tag to which DLCs are anchored. However,t heir biological applications are often limited by their photophysical and/orb iological properties.…”