A Ratiometric Fluorescent Probe Based on a Through‐Bond Energy Transfer (TBET) System for Imaging HOCl in Living Cells

Abstract

A simple ratiometric probe (Naph-Rh) has been designed and synthesized based on a through-bond energy transfer (TBET) system for sensing HOCl. In this probe, rhodamine thiohydrazide and naphthalene formyl were connected by simple synthesis methods to construct a structure of monothio-bishydrazide. Free probe Naph-Rh showed only the emission of naphthalene. When probe Naph-Rh reacted with HOCl, monothio-bishydrazide could be converted into 1,2,4-oxadiazole, which not only ensured that the donor and the acceptor were connected with electronically conjugated bonds, but also resulted in the spiro-ring opening and the emission of rhodamine. Therefore, a typical TBET process took place. The probe possessed high-energy transfer efficiency and large pseudo-Stokes shifts. As the first TBET probe for HOCl, Naph-Rh showed excellent selectivity and sensitivity toward HOCl over other reactive oxygen species (ROS)/reactive nitrogen species (RNS), and could respond fast to a low concentration of HOCl in the real sample. In addition, the probe was suitable for imaging HOCl in living cells due to its real-time response, excellent resolution, and reduced cytotoxicity.

Bioanalytical methods for hypochlorous acid detection: Recent advances and challenges

“…However, when the donor-acceptor pair is connected through an electronically conjugated bond, the spectrum overlap becomes less important for the energy transfer since the TBET is dominated. Zhang et al reported the first TBETbased ratiometric fluorescence probe, Naph-Rh, for detection of HOCl [229]. In this probe, naphthalene (ex = 350 nm, em = 440 nm) was selected as the energy donor.…”

A lysosome-targeted and ratiometric fluorescent probe for imaging exogenous and endogenous hypochlorous acid in living cells

“…Some small molecular based ratiometric HOCl probes have been constructed successfully. [25][26][27][28][29][30][31][32][33][34][35][36][37][38] In addition, some excellent nanoparticles based probe via ratiometric imaging and photoluminescence lifetime imaging microscopy to detect intracellular exogenous and endogenous HClO has been reported. 39 Even though most of them have been applied to image intracellular HOCl, few small molecular fluorescent probes were used to image of HOCl in lysosomes.…”

A General Strategy for Through‐Bond Energy Transfer Fluorescence Probes Combining Intramolecular Charge Transfer: A Silyl Ether System for Endogenous Peroxynitrite Sensing

“…[1] Thus, there is no requirement for substantial spectral overlap between the donor emission and acceptora bsorbance, [2] leading to al arge pseudo-Stokes shifts (PSS) and emission shift, which is favorable to avoid self-quenching andf luorescence detectione rrors becauseo fe xcitation back-scattering effects. Althoughn umerousr atiometric fluorescence probes have been implemented with TBET mechanism, thesep robes are predominantly based on spirolactam ring-opening to sensing ions or molecules (Figure 1a), such as Hg 2 + ions, [4][5][6][7][8][9][10][11][12][13] Cu 2 + , [14][15][16] Pd 2 + , [17] Sn 2 + , [18] Ce 4 + , [19] À OCl, [20][21][22][23] picric acid [24] and so on. Althoughn umerousr atiometric fluorescence probes have been implemented with TBET mechanism, thesep robes are predominantly based on spirolactam ring-opening to sensing ions or molecules (Figure 1a), such as Hg 2 + ions, [4][5][6][7][8][9][10][11][12][13] Cu 2 + , [14][15][16] Pd 2 + , [17] Sn 2 + , [18] Ce 4 + , [19] À OCl, [20][21]…”