Polyvinylpyrrolidone composite nanofibers as efficient substrates for surface-assisted laser desorption/ionization mass spectrometry

A matrix-free laser desorption/ionization mass spectrometry (LDI-MS) approach was developed using electrospun composite nanofibers with controllable size, morphology and composition. Composite polyvinylpyrrolidone (PVP) nanofibers with added nanoparticles to enhance the absorption of laser energy absorber were studied. Fractal dimensional analysis was conducted to evaluate the electro-spinning process for the first time, which provided useful information on the repeatability of nanofiber production. The performance of the nanofiber-assisted laser desorption/ionization method was investigated through characterization of small drug molecules and synthetic oligomers. Homogeneous sample distribution was achieved by eliminating the "sweet spot", resulting in good reproducibility. Mass spectra features clean background, that is especially beneficial for interpretation of small molecules. High sensitivity for small drug molecules and synthetic oligomers was obtained with limits of detection limits down to the low attomolar range. The combination of composite nanofibers with LDI-MS is a versatile and sensitive approach for detection and characterization of analytes with broad range of molecular weight. (C) 2019 Elsevier B.V. All rights reserved.