Quantifying lysosomal glycosidase activity within cells using bis-acetal substrates

VOC-Based Probes, a New Set of Analytical Tools to Monitor Patient Health from Blood Sample. Proof of Concept on Tracking COVID-19 Infection

“…Being related to viral infectivity and pathogenicity, this lysosomal trafficking could thus explain why we did detect an acute upregulation of circulating glycosidases within a few days after infection, especially in the plasma of severe cases. This outcome is particularly relevant for a highly active extracellular exoglycosidase, , β-GlcNac. Indeed, its activity was augmented in plasma of all infected patients (either moderate or severe) before decreasing to a basal level 1 week later.…”

“…Such an outcome is a great advantage in comparison with fluorescent probes which cannot be used in a cocktail due to imaging interferences. 22 Moreover, our strategy shows advances in terms of sensitivity and normalization since the biological matrix will not interfere with the detection of exogenous volatile tracers.…”

Fluorogenic In Situ Thioacetalization: Expanding the Chemical Space of Fluorescent Probes, Including Unorthodox, Bifurcated, and Mechanosensitive Chalcogen Bonds

“…Thio/acetals are popular functional groups in fluorescent probes. Thioacetals have been used for mercury sensing, − quenching, − and the detection of reactive oxygen species, − while acetals have been used to sense pH changes, − detect metal ions, − visualize and modulate enzyme activity, − and for photochromic switching − and super-resolution microscopy . Usually, the conversion of aldehydes into thio/acetals is designed to turn off fluorescence, or vice versa , for different reasons.…”

Ratiometric sensing of β-galactosidase based on excited-state intramolecular proton transfer (ESIPT) and solid-state luminescence enhancement

“…[10][11][12][13][14][15][16][17] Based on a variety of fluorescent dyes, molecular probes capable of sensing glycosidases in cells and in vivo with emission wavelengths that range from the visible to the near-infrared region, have been synthesized in recent years. [18][19][20][21][22][23][24][25][26][27] Here, we report the construction of a ratiometric fluorescent probe that exhibits a large Stokes shift of the fluorescence emission wavelength upon hydrolysis by glycosidases based on the combination of excited-state intramolecular proton transfer (ESIPT) and solid-state luminescence enhancement (SSLE). [28][29][30] The probe is a typical SSLE system when glycosylated, and after deglycosylation, the ESIPT process is activated, thereby achieving a ∼140 nm red-shift in fluorescence emission.…”

“…10–17 Based on a variety of fluorescent dyes, molecular probes capable of sensing glycosidases in cells and in vivo with emission wavelengths that range from the visible to the near-infrared region, have been synthesized in recent years. 18–27…”