title: 3D-printed polylactic acid supports for enhanced ionization efficiency in desorption electrospray mass spectrometry analysis of liquid and gel samples.
abstract: The potential of 3D printing technology was here exploited to prepare tailored polylactic acid (PLA) supports for desorption electrospray ionization (DESI) experiments. PLA rough solid supports presenting wells of different shape (i.e. cylindrical, cubic and hemispherical cavities) were designed to accommodate samples of different physical state. The potentials of such supports in terms of sample loading capacity, sensitivity, signal stability were tested by analysing a peptide (i.e. insulin) and an aminoglycoside antibiotic (i.e. gentamicin sulphate) from solution and a chitosan-based gel. The results obtained were compared with those obtained by using a traditional polytetrafluoroethylene (PTFE) support and discussed. By using PLA support on the flat side, signal intensity improved almost twice with respect to PTFE support, whereas with spherical wells a five times improved signal sensitivity and good stability (RSD<6%) were obtained for the analysis of two model molecules. Limits of detection were in the 3-10nM range and linearity was demonstrated for both analytes in the 0.05-0.5μM range for semi-quantitative or quantitative purposes. The use of a well and the set-up of optimal source parameters allowed the analysis of samples in a gel state with good precision (RSD<10%) and accuracy (86±6-102±9%), otherwise difficult to analyse on a flat smooth surface. These findings are of great interest and stimulus to exploit the advantages of 3D printing technology for the development of devices for a DESI source, presenting different shapes or configuration as a function of the sample types.
authors.affiliation: Department of Pharmacy, University of Parma, Parco Area delle Scienze 27/A, 43124 Parma, Italy. Electronic address: lisa.elviri@unipr.it.
authors.forename: Lisa
authors.initials: L
authors.lastname: Elviri
authors.affiliation: Department of Industrial Engineering, University of Parma, V.le delle Scienze 181/A, 43124, Parma, Italy.
authors.forename: Ruben
authors.initials: R
authors.lastname: Foresti
authors.affiliation: Interdepartmental Centre Biophamanet Tec, University of Parma, V.le delle Scienze 27/A, 43124 Parma, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Bianchera
authors.affiliation: Department of Industrial Engineering, University of Parma, V.le delle Scienze 181/A, 43124, Parma, Italy; Department of Innovative Technologies, University of Applied Sciences and Arts of Southern Switzerland (SUPSI), CH-6928 Manno, Switzerland.
authors.forename: Marco
authors.initials: M
authors.lastname: Silvestri
authors.affiliation: Department of Pharmacy, University of Parma, Parco Area delle Scienze 27/A, 43124 Parma, Italy.
authors.forename: Ruggero
authors.initials: R
authors.lastname: Bettini
keywords: 3D-printing; Desorption electrospray ionization; Polylactic acid