Amphiphilic Conjugated Polythiophene‐based Fluorescence “Turn on” Sensor for Selective Detection of Escherichia coli in Water and Milk

Abstract

The ability to detect pathogenic microbes in water and food samples is of prominent interest, but it remains a great challenge. Herein, we report a simple fluorescence sensor based on amphiphilic conjugated polythiophene (ACPT) for the detection of gram-negative pathogenic bacteria, Escherichia coli, in pH 7.0. The ACPT sensor was synthesized by the oxidative polymerization of water-soluble thiophene monomers in an aqueous solution. The ACPT sensor undergoes the fluorescence "turn on" response at 432 nm upon the addition of E. coli. The ionic complex, which is generated by electrostatic interaction during the short incubation time of 15 min, resulting in the enhancement of the fluorescence intensity of ACPT. The application of ACPT enables the detection of E. coli pathogens in tap water and milk samples with good recoveries of 96.94-100.83% and 93.27-116.75%, respectively, and excellent reproducibility (n = 3, relative standard deviation [RSD] = 1.78%). The current findings pave the way for the promising application of a novel ACPT system that could be used in food safety and environmental monitoring.

Lignin‐based materials for the detection and adsorption of metal ions

“…The active components of chemical sensors and biosensors consist of conductive materials, chromophores, or fluorescent molecules. For example, carbon nanotubes and graphene are employed in chemiresistor‐type or field‐effect transistor‐type sensors, 20–26 and chromophores or fluorophores are used as sensors that can be readily detected by naked eyes 27–35 . One critical issue related to these materials is that most of them are often fossil fuel‐derived and thus emit greenhouse gases during their production with a large amount of energy input.…”

“…For example, carbon nanotubes and graphene are employed in chemiresistor-type or field-effect transistor-type sensors, [20][21][22][23][24][25][26] and chromophores or fluorophores are used as sensors that can be readily detected by naked eyes. [27][28][29][30][31][32][33][34][35] One critical issue related to these materials is that most of them are often fossil fuel-derived and thus emit greenhouse gases during their production with a large amount of energy input. Therefore, the replacement of them with lignin biomass would be able to contribute to reducing the level of carbon dioxide emission, saving energy/electricity to produce materials, and thus achieving sustainable production of materials in the upcoming years.…”