9-Nitrobenzo[b]quinolizinium as a fluorogenic probe for the detection of nitroreductase in vitro and in Escherichia coli

Abstract

The non-fluorescent 9-nitrobenzo[b]quinolizinium is readily reduced by nitroreductase to fluorescent reaction products whose formation depends on the reaction conditions.

Recent advances in bioelectrochemical detection of E. coli bacteria in saline buffers and spiked real samples using traditional and nanostructured active substrates

“…One the other hand, the induction of intracellular enzyme β-galactosidase (Gal) encoded by lacZ operon [11] is commonly used as a cytoplasmatic marker [12] for sensitive and selective E. coli detection in aqueous and food samples using fluorogenic [13,14] and redox compounds such as ferrocene, lipophilic benzoquinone (BQ) to mediate the intracellular metabolic activities [15]. Despite the widespread use of traditional culture plate [16], PCR [17], colorimetric [18,19] and enzyme immunoassays (ELISA) [20], more recent and advanced techniques based on optical and/or electrochemical immunosensor technologies have been developed due to their excellent performance in terms of cost-effectiveness, rapid response, high sensitivity/selectivity and ability to integrate with a smartphone interface [21].…”

Fluorogenic Protein Labeling by Generation of Fluorescent Quinoliziniums Using [Cp*RhCl2]2

“…Quinolizinium compounds have shown remarkable advantages, including excellent fluorescence signal, high photostability, good water solubility, good cellular localization, as well as potent bioactivity. , Hence, quinolizinium compounds were used as fluorescence imaging probes, DNA detection dyes, photocatalysts, and promising drug candidates. ,− On the basis of our previous work and the advantages of rhodium catalysts, we aim to use [Cp*RhCl 2 ] 2 -catalyzed quinolizinium formation for turn-on fluorogenic bioconjugation because of high cost efficiency, simple synthetic method, and scalable reagent synthesis.…”