Enhancing protein trapping efficiency of graphene oxide-polybutylene succinate nanofiber membrane via molecular imprinting

Abstract

Filtration of biological liquids has been widely employed in biological medical and environmental investigations due to its convenience; many could be performed without energy and on-site particularly protein separation. However most available membranes are universal protein absorption or sub-fractionation due to molecule sizes or properties. SPMA or syringe-push membrane absorption is a quick and easy way to prepare biofluids for protein evaluation. The idea of initiating SPMA was to filter proteins from human urine for subsequent proteomic analysis. In our previous study we developed nanofiber membranes made from polybutylene succinate (PBS) composed of graphene oxide (GO) for SPMA. In this study we combined molecular imprinting with our developed PBS fiber membranes mixed with graphene oxide to improve protein capture selectivity in a lock-and-key fashion and thereby increase the efficacy of protein capture. As a model we selected albumin from human serum (ABH) a clinically significant urine biomarker for proteomic application. The nanofibrous membrane was generated utilizing the electrospinning technique with PBS/GO composite. The PBS/GO solution mixed with ABH was injected from a syringe and transformed into nanofibers by an electric voltage which led the fibers to a rotating collector spinning for fiber collection. The imprinting process was carried out by removing the albumin protein template from the membrane through immersion of the membrane in a 60% acetonitrile solution for 4爃 to generate a molecular imprint on the membrane. Protein trapping ability high surface area the potential for producing affinity with proteins and molecular-level memory were all evaluated using the fabricated membrane morphology protein binding capacity and quantitative protein measurement. This study revealed that GO is a controlling factor increasing electrical conductivity and reducing fiber sizes and membrane pore areas in PBS-GO-composites. On the other hand the molecular imprinting did not influence membrane shape nanofiber size or density. Human albumin imprinted membrane could increase the PBS-GO membrane抯 ABH binding capacity from 50 to 83%. It can be indicated that applying the imprinting technique in combination with the graphene oxide composite technique resulted in enhanced ABH binding capabilities than using either technique individually in membrane fabrication. The suitable protein elution solution is at 60% acetonitrile with an immersion time of 4爃. Our approach has resulted in the possibility of improving filter membranes for protein enrichment and storage in a variety of biological fluids. ? 2023 Springer Nature Limited.