Development of Highly pH-Sensitive Hybrid Membranes by Simultaneous Electrospinning of Amphiphilic Nanofibers Reinforced with Graphene Oxide

Abstract

Nanofibrous-based pH sensors have shown promise in a wide range of industrial and medical applications due to their fast response time and good mechanical properties. In the present study, we fabricated pH-sensitive sensors of nanofibrous membranes by electrospinning polyurethane (PU)/poly 2-acrylamido-2-methylpropanesulfonic acid (PAMPS)/graphene oxide (GO) with indicator dyes. The morphology of the electrospun nanofibers was examined using scanning electron microscopy (SEM). The effect of hydrophilic polymer ratio and concentration of GO on the sensing response time was investigated. The sensitivity of the membranes was studied over a wide pH range (1–8) in solution tests, with color change measured by calculating total color difference using UV-vis spectroscopy. The membranes were also subjected to vapor tests at three different pH values (1, 4, 8). SEM results show the successful fabrication of bimodal fiber diameter distributions of PU (mean fiber diameter 519 nm) and PAMPS (mean fiber diameter 78 nm). Sensing response time decreased dramatically with increasing concentrations of PAMPS and GO. The hybrid hydrophobic/hydrophilic/GO nanofibrous membranes are capable of instantly responding to changes in solution pH as well as detecting pH changes in chemical vapor solution in as little as 7 s.

Biomedical Applications of Electrospun Graphene Oxide

“…The inclusion of GO into an electrospun material for use in medical devices and biomaterials can improve its hydrophilicity due to the existence of oxygen-abundant functional groups on the nanomaterial. , It is also widely reported that GO improves mechanical features such as tensile strength, ductility, electroconductivity, etc. when included in an electrospun matrix. ,, While we understand that the use of GO in small concentrations in areas such as tissue engineering, drug delivery, wound healing, etc.…”

Graphene-Fiber Biochemical Sensors: Principles, Implementations, and Advances

“…In this section, we systematically classify the sensing objects of biochemical sensors into gas and liquid categories. Among them, gases include gas molecules, water molecules, and volatile substances, while liquids mainly include carbohydrates, biomacromolecules, aqueous ions, and other clinically relevant analytes [48][49][50][51][52]. In the following content, we will introduce the latest research progress of graphene-fiber sensors, including different sensing structures and sensing targets, and analyze their sensing performances.…”

Graphene impregnated electrospun nanofiber sensing materials: a comprehensive overview on bridging laboratory set-up to industry

“…Dispersion GNMs into polymer matrices have been reported to improve the electrical, mechanical, thermal properties and other properties of polyslfones [186,187], polyimide [188,189], polycarbonates [190,191], polyamides [192,193], polyethylene terephthalate [192,193] and polybutylene terephthalate [194,195]. Gorji et al [196] reported that the incorporation of GO into electrospun of PU and pH-sensitive dyes contributed to a faster response (7 s) and improved the sensor's sensitivity to detect pH in chemical vapor solution. Table 3 summarizes the recent studies on impregnating GNMs into ESNFs and the subsequent improved properties.…”