Construct the micro fluidic nozzles to electrospray ionizing large biomolecules in mass spectrometry analyzing

A novel and simple technique is implemented to construct the spray nozzle tips on the glass microchips with 50μm width by 20μm depth channels. The microchips are fabricated in following the conventional photolithography and glass wet etching processes. The nozzles are diced using the wafer dicing machines, which is integrated the nozzle fabrication step at the same dicing step. The chips are cut through the substrate in the x-y plane and saw the depth of the chip exquisitely to form the spray nozzle in the z-axis. The SEM view of nozzles and Taylor cone of electrospray are demonstrated. The green fluorescent protein is the sample to verify the spray nozzle function and mass spectrometry was obtained.