Absorbance biosensors-based hybrid $$\mathbf {MoS_{2}}$$ nanosheets for Escherichia coli detection

Abstract

AbstractDetecting 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 $$\text {MoS}_\text {2}$$ MoS 2 and $$\mathrm {(NH_4)_6Mo_7O_{24}}$$ ( NH 4 ) 6 Mo 7 O 24 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 $$\text {NH}_\text {2}$$ NH 2 -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-$$\mathrm {MoS_2}$$ MoS 2 and $$\mathrm {(NH_4)_6Mo_7O_{24}}$$ ( NH 4 ) 6 Mo 7 O 24 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 $$\text {NH}_\text {2}$$ NH 2 -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.