Insoluble electrospun membranes for analyte pre-concentration in saliva

Abstract

Insoluble electrospun membrane based on poly acrylic acid (PAA) crosslinked with ethylene glycol (EG) was prepared. The surface of the crosslinked PAA fibers was then grafted with polyethylenimine (PEI), octyl amine (OA) and EG using carbodiimide or thermal crosslinking to obtain insoluble membranes having anionic, cationic, hydrophobic and neutral characteristics for filtration of biomolecules from saliva. The resulting surface chemistries were confirmed by their respective ATR-FTIR spectra. Differences in fiber morphology and diameters were observed between the membranes. All the membrane variants were tested for their efficacy as solid phase extraction (SPE) matrices in the pre-concentration of ethanol in synthetic saliva, using a microfluidic chip. Gas chromatography assays showed no statistical difference for ethanol in eluents through each of the tested insoluble electrospun membrane variants versus their corresponding controls. Further studies would include the testing of these membranes in the pre-concentration of clinical biomolecules, including drugs of abuse (e.g., cocaine, THC), nutrients (e.g., glucose), proteins (e.g., albumin, HbA1C) and nucleic acids for sample preparation within point of care devices.