Enzyme-responsive chitosan-based electrospun nanofibers for enhanced detection of β-glucuronidase from pathogenic E. coli

Abstract

Antimicrobial resistance (AMR) poses a significant global health challenge, leading to the ineffectiveness of numerous conventional antibiotics against various bacterial infections. Hence the rapid detection and identification of pathogenic bacteria are imperative for managing AMR and implementing suitable treatment approaches. To improve rapid detection, a biopolymer-based autonomously reporting enzyme-sensitive biopolymer material has been developed for detecting β-glucuronidase (β-Gus) from pathogenic E. coli. In the presence of enzyme β-Gus a blue-colored fluorophore is released from functionalized electrospun chitosan-polyethylene oxide nanofibers, which is monitored via fluorescence spectroscopy. The nanofibers exhibited a 3.4 times enhanced sensitivity compared to neat hydrogels and also to related chromogenic sensing materials. For an observation time of 60 min, a limit of detection (LOD) for β-Gus was determined to be 4.7 nM. This nanofiber sensing substrate was then studied with the pathogenic E. coli strain NCTC 10418, showing a three times greater sensitivity compared to the hydrogel substrate. These results are attributed to a larger surface to volume ratio of the electrospun chitosan nanofibers compared to the neat swollen hydrogel.