Influence of nanostructures of surface-assisted laser desorption/ionization substrates using porous alumina membranes on mass spectrometry signal intensity

Abstract Matrix-assisted laser desorption/ionization (MALDI) is effective for the identification of microbes, drugs, and polymeric materials, particularly biopolymers. Compared to MALDI, surface-assisted laser desorption/ionization (SALDI) has the advantages of no interfering peaks in the low-molecular-weight region, easy sample preparation, and high reproducibility. The SALDI substrate was prepared by using an anodic porous alumina membrane (APAM). To investigate the effect of the APAM nanostructure on mass spectrometry (MS) signal intensity, the APAM was prepared by anodizing an Al substrate at 40–250 V to control the interpore distance. The pore diameters were adjusted to 24–419 nm using a pore-widening treatment. The APAM sample with a pore diameter of 131 nm prepared at 110 V exhibited the highest MS signal intensity. This optimized APAM is expected to be a useful SALDI substrate for highly sensitive MS.