Thiol–ene micropillar array electrospray ionization platform for zeptomole level bioanalysis

Abstract

A micropillar array electrospray ionization (μPESI) platform fabricated from thiol–enes with 56 individual polyethylene glycol coated μPESI chips for bioanalytical mass spectrometry is introduced. Bioanalysis capability is shown by measurement of a protein, a protein digest and a cell lysate sample. The thiol–ene polyethylene glycol (PEG) coated μPESI chip allows the use of a wide range of aqueous–organic solvent compositions and provides a detection limit at 60 zeptomole level (6 × 10⁻²⁰ mol) for a peptide standard.