Highly efficient capture of E. coli using amidoximated polyacrylonitrile nanofiber membrane immobilized with reactive green 19 dye/polyhexamethylene biguanide: Antibacterial and cytotoxicity studies

Abstract

In this study, we synthesized an amidoximated polyacrylonitrile nanofiber membrane (P-Oxime). Subsequently, we grafted reactive green 19 (RG19) dye onto its surface, resulting in the formation of the P-Oxime-RG19 membrane. Further enhancement was achieved by physically attaching poly(hexamethylene biguanide) hydrochloride (PHMB) to the P-Oxime-RG19 membrane, leading to the formation of the P-Oxime-RG19-PHMB membrane. Extensive characterization of the nanofiber membranes was conducted, focusing on crucial physical and mechanical properties such as functional group content, morphology, and thermostability. The optimization of various modification conditions, including initial dye and PHMB concentrations, duration, temperature, and nitrile group conversion to oxime concentrations, played a pivotal role in achieving superior antibacterial performance in P-Oxime-RG19-PHMB nanofiber membranes. In-depth analyses involved the application of kinetic and equilibrium thermodynamic models to unravel the modification processes of RG19 dye and PHMB in the nanofiber membranes. Under the carefully tuned optimal modification conditions, the P-Oxime-RG19-PHMB nanofiber membrane exhibited remarkable antibacterial efficacy, achieving nearly 100% disinfection of E. coli. In addition to exploring its antimicrobial capabilities, we thoroughly examined the repeatability and biocompatibility of the nanofiber membranes. The results indicated not only the P-Oxime-RG19-PHMB nanofiber membrane was a highly promising antibacterial material but also highlighted its potential for diverse applications, particularly in food and textile fabrication, owing to its exceptional performance and suitability.