Absorbance biosensors‑based hybrid MoS2 nanosheets for Escherichia coli detection

Abstract

Detecting Escherichia coli is essential in biomedical, environmental, and food safety applications. In this paper, we have developed a simple, rapid, sensitive, and selective E. coli DNA sensor based on the novel hybrid-type MoS2 and (NH4)6 Mo7 O24 nanosheets. The sensor uses the absorbance measurement to distinguish among the DNA of E. coli, Vibrio proteolyticus, and Bacillus subtilis when implemented in conjunction with NH2-probes. Our experiments showed that the absorbance increased when sensors detected E. coli DNA, whereas it decreased when sensors detected V. proteolyticus and B. subtilis DNA. To the best of authors’ knowledge, there are no reports using the novel hybrid-MoS2 and (NH4)6 Mo7 O24 materials for differentiating three types of DNA using cost-effective and rapid absorbance measurements. In addition, the label-free E. coli DNA biosensor exhibited a linear response in the range of 0 fM to 11.65 fM with a limit of detection of 2 fM. The effect of NH2-probes on our sensors’ working performance is also investigated. Our results will facilitate further research in pathogen detection applications, which have not been fully developed yet.