Fabrication of sample target plate for MALDI-TOF MS using proton beam writing

Ion beam irradiation of silicon followed by electrochemical etching has been used to produce fluid anchor points on a sample target plate for matrix assisted laser desorption ionization mass spectrometry. Non-porous areas on the fabricated target plate serve as anchor points for sample deposition. High hydrophobicity of the macroporous silicon surface surrounding anchor points intrinsically led to a better sample confinement and gave the possibility to deposit large volumes of sample at predefined spot areas, improving the sensitivity in bioanalyte readout. We also have found that irradiation with beam fluences lower than 1014 cm−2 led to the enhanced anodization rate producing inverse structures.