“…Various attempts have been made to produce the highest signal and the least ionization suppression (Leuthold et al, 2006;Wiseman et al, 2010). An increasing number of commercial or homemade substrates, including silicon-based materials, such as glass slides (Pasilis et al, 2007;Manicke et al, 2008) and glass slides coated with heavy Teflon coating (HTC) material (Mattarozzi et al, 2012), and thin-layer chromatographic plates (Kauppila et al, 2006), porous silicon chips (Schwab et al, 2014), and carbon-based materials, such as polymethyl methacrylate (Volny et al, 2008), PTFE (Manicke et al, 2008;Volny et al, 2008), PTFE-printed glass (Manicke et al, 2008), paper (Manicke et al, 2008) and porous Teflon membranes (Rosting et al, 2013;Sero et al, 2015), have been investigated for DESI-MS analysis. From these studies, we have concluded that an electrically nonconductive material could enhance the response of DESI-MS since the material preserves charges by avoiding neutralization of the incoming ion plume at the surface.…”