Ammonia plasma-treated electrospun polyacrylonitryle nanofibrous membrane: the robust substrate for protein immobilization through glutaraldhyde coupling chemistry for biosensor application

Matin Mahmoudifard,Manuchehr Vossoughi,Masoud Soleimani

doi:10.1038/s41598-017-10040-7

Abstract

The surface of polyacrylonitrile electrospun nanofibrous membrane (PAN NFM) was aminated by the ammonia plasma treatment. The content of amine groups has been estimated for different time of plasma treatment. The newly generated amine groups were successfully activated by glutaraldehyde (Ga) for the covalent attachment of the protein molecules on the NFM surface. Bio-functionalization of ammonia plasma treated PAN NFM was carried out by the primary antibodies (Ab) immobilization as a protein model through Ga coupling chemistry. For comparison, the immobilization of Ab was also performed through physical interactions. Attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR) was used for the characterization of surface functional groups of PAN NFM after different modifications. The surface morphology of the NFM after immobilization was characterized using scanning electron microscope (SEM). The efficacy of Ab immobilization was estimated by enzyme-linked immuno sorbent assay (ELISA) method. X- Ray photoelectron spectroscopy (XPS) was performed to confirm the covalent immobilization of Ab on the modified PAN NFM. Results show that ammonia plasma treatment effectively increased the amount of Ab immobilization through Ga coupling chemistry. Our findings suggest that this is a versatile model for the preparation of stable bio-functionalized NFM which is applicable in different field of biomedical science.

Highlights

Protein biomarkers detection using a biosensor devices is the standard method for early detection of diseases such as cancer, cardiac vascular attacks[1, 2], alzheimer[3] and infection[4]
Similar observation reported in another study in which PAN fibers were reduced through chemical reaction of lithium aluminum hydride[17]
Amine group were successfully created on the surface of polyacrylonitrile electrospun nanofibrous membrane (PAN NFM) through ammonia plasma modification

Summary

Introduction

Protein biomarkers detection using a biosensor devices is the standard method for early detection of diseases such as cancer, cardiac vascular attacks[1, 2], alzheimer[3] and infection[4]. About Ab immobilization, an ideal orientation of the Ab is end-on form which means the Fc region of Ab adsorbs onto the solid surface and the Fabs region orient toward the analyte solution (end-on)[9] As it is mentioned, commonly used immobilization methods namely, physical absorption technique suffers from non-specific interaction which may lead to desorption of the biomolecule during the intensive washing steps[13,14,15]. Creating covalent immobilization of biomolecules on the non-functionalized surfaces including PS is impossible For example it was proposed[16] to graft methacrylate on PS micro-titer plate to enhance proteins immobilization but it was reported that such system suffer from poor reproducibility. The feasibility of Ab immobilization through Ga coupling chemistry on the ammonia plasma treated PAN NFM was assessed

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Results

Conclusion