pH-activatable near-infrared fluorescent probes for detection of lysosomal pH inside living cells

Abstract

Four near-infrared fluorescent probes have been synthesized, characterized, and evaluated for detection of lysosomal pH inside living cells.

Luminescent Probes for Sensitive Detection of pH Changes in Live Cells through Two Near-Infrared Luminescence Channels

“…34,39 However, the fluorophore displays very poor water solubility and possesses severe cytotoxicity. 34 In order to overcome these drawbacks, we used mannose to enhance water solubility and biocompatibility of the fluorophore. We prepared two fluorescent probes bearing one and two mannose residues to study the effect of mannose residues on the probe sensitivity to pH changes.…”

“…Compounds 3 and 5 34 and 1- O -bromoethyl-2,3,4,6-tetra- O -acetyl-α-D-mannose (8) 46,47 were synthesized according to reported procedures.…”

“…12,13,20,24,32,33 In order to address these issues, a few near-infrared fluorescent probes have been reported for detection of pH. 26,27,34 However, all fluorescent probes, which are based on small organic fluorophores for pH detection in live cells, use conventional fluorescence (CF) instead of single-photon frequency upconversion luminescence (FUCL). Upconversion luminescent materials such as two-photon absorption organic dyes and lanthanide-doped upconversion nanoparticles are excited by longer wavelength light and emit in shorter regions.…”

Near-infrared fluorescent probe for sensitive detection of Pb(II) ions in living cells

“…For designing NIR-PbP - a near-infrared emissive probe for Pb(II) - we chose a compound 1 (Scheme 1) as a unique dye combining large extinction coefficient, high quantum yield, near-infrared emissions (720 nm), photostability, and the controlled fluorescence on-off switching mechanism [29, 30]. Compunds 1 was synthesized following reported procedures [29, 30], and coupled with dipicolylamine derivative (N1,N1-bis(pyridin-2-ylmethyl)ethane-1,2-diamine) ( 2 ) [31] as a strong electron-donating group that selectively chelates to Pb +2 ions via an amidation reaction [24].…”

A water-soluble pH fluorescence probe based on quaternary ammonium salt for bioanalytical applications

“…In the past decades, quite a few fluorescence probes have been developed for various bio-related targets based on target-triggered fluorescence intensity changes [17][18][19][20][21][22][23][24][25] due to their high sensitivity, fast analysis with spatial resolution for providing in situ and real-time information and nondestructive sample preparation. Moreover, fluorescence microscopic imaging technique can map the spatial and temporal distribution of analytes within living cells [26][27][28][29][30][31][32].…”