A novel near-infrared fluorescent probe for sensitive detection of β-galactosidase in living cells

• Published in: Analytica chimica acta Vol. 968; pp. 97 - 104
• Main Authors: Zhang, Jingtuo, Li, Cong, Dutta, Colina, Fang, Mingxi, Zhang, Shuwei, Tiwari, Ashutosh, Werner, Thomas, Luo, Fen-Tair, Liu, Haiying
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 22.05.2017
• Subjects: Fluorescence imaging; Fluorescent probe; Live cells; Near-infrared emission; β-Galactosidase; Live cells; Fluorescence imaging; β-Galactosidase; Near-infrared emission; Fluorescent probe
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2017.02.039

A novel near-infrared fluorescent probe for β-galactosidase has been developed based on a hemicyanine skeleton, which is conjugated with a d-galactose residue via a glycosidic bond. The probe serves as a substrate of β-galactosidase and displays rapid and sensitive turn-on fluorescent responses to β-galactosidase in aqueous solution. A 12.8-fold enhancement of fluorescence intensity at 703 nm was observed after incubation of 10 nM of β-galactosidase with 5 μM probe for 10 min. The probe can sensitively detect as little as 0.1 nM of β-galactosidase and shows linear responses to the enzyme concentration below 1.4 nM. The kinetic study showed that the probe has high binding affinity to β-galactosidase with Km = 3.6 μM. The probe was used to detect β-galactosidase in living cells by employing the premature cell senescence model. The probe exhibited strong fluorescent signals in senescent cells but not in normal cells, which demonstrates that the probe is able to detect the endogenous senescence-associated β-galactosidase in living cells. [Display omitted] •A novel fluorescent probe for β-galactosidase with near-infrared emission.•The probe has rapid and sensitive turn-on responses to β-galactosidase in aqueous solution.•The probe has high photostability and low background fluorescence.•The probe is able to detect the senescence-associated β-galactosidase in living cells.