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Coumarin-based, switchable fluorescent substrates for enzymatic bacterial detection

Giovannini, Giorgia, Hall, Andrew J., Gubala, V. (2018) Coumarin-based, switchable fluorescent substrates for enzymatic bacterial detection. Talanta, 188 . pp. 448-453. ISSN 0039-9140. (doi:10.1016/j.talanta.2018.06.018) (KAR id:67444)


Enzymatically-switchable fluorescent substrates, such as the commercially available 4-methyl umbelliferones (4-MU) are used as standard indicators of enzymatic activity for the detection of various microorganisms and pathogens. However, a major disadvantage of 4-MU is its relatively high pKa leading to only partial dissociation of the fluorescent anion under the conditions where the enzymes are most effective (pH 6–6.5). Here we present a method for new, enzymatically-switchable, fluorescent substrates with improved photo-physico/chemical properties. The lead derivative, 4-AAU, shows excellent solubility in aqueous media (0.81?mg/mL) when compared to 4-MU (0.16?mg/mL), significantly improved quantum yield and wider dynamic range of its fluorescence properties. The corresponding bacterial substrate ?-4-AAUG showed superior selectivity in the detection of clinically relevant amounts of E. coli, Enterococcus and K. pneumonia (1 CFU). The fluorescence intensity of ?-4-AAUG was almost 5 times higher than that of the standard, the detection was possible in reasonably short time (? 2.5?h) and with excellent sensitivity.

Item Type: Article
DOI/Identification number: 10.1016/j.talanta.2018.06.018
Uncontrolled keywords: Bacterial detection, Coumarin, Switchable probe, Fluorescent probe, Epimerisation, Medway School of Pharmacy
Subjects: Q Science > QD Chemistry > QD431 Organic Chemistry- Biochemistry- Proteins, peptides, amino acids
Q Science > QD Chemistry > Analytical Chemistry
Divisions: Divisions > Division of Natural Sciences > Medway School of Pharmacy
Central Services > Research and Innovation Services
Depositing User: Vladimir Gubala
Date Deposited: 28 Jun 2018 15:06 UTC
Last Modified: 09 Dec 2022 06:07 UTC
Resource URI: (The current URI for this page, for reference purposes)

University of Kent Author Information

Giovannini, Giorgia.

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Hall, Andrew J..

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Gubala, V..

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