Patterning parameters for biomolecules microarrays constructed with nanosecond and femtosecond UV lasers

The development of laser techniques for transferring biomolecules on solid surfaces in a controlled manner has attracted much attention during the last few years. Laser-induced forward transfer (LIFT) is a direct-write laser technique employed in printing micron-sized patterns or features of a wide range of materials in solid or liquid state, in ambient atmosphere and temperature or in vacuum. In this work, we use LIFT with nanosecond and femtosecond UV lasers for patterning the proteins Biotin, Avidin and Titin. In addition to the laser parameters, we also investigate the influence of the solution viscosity and the receiving surface wettability on the formed patterns. To confirm pattern functionality after transfer, we employ the strategy of patterning a coupling molecule with LIFT, immobilizing an active complementary protein on it and performing a fluorescence microscopy assay afterwards. Our results show that both nanosecond and femtosecond lasers are suitable tools for obtaining micron size protein patterns, with femtosecond laser pulses requiring a lower energy for transfer. We also show that the smallest patterns are formed just above the threshold energy for the thinnest target and that the pattern size increases with increasing surface wettability and decreases with solution viscosity.