Fabrication of SU-8 microreactors for radiopharmaceutical production

SU-8 is a very interesting material for the fabrication of lab-on-chip devices applied to organic synthesis because of its resistance to chemicals and solvents. Among the possible application fields of microreactor technology, radiochemistry is emerging because microfluidic apparatuses allow to perform radiosynthesis in a quicker, safer and more reliable way compared to traditional vessel-based approaches. Microreactors for synthesizing [18F]-labelled radiopharmaceuticals require the employment of materials that do not adsorb fluoride and are resistant to solvents and chemicals. Pyrex, glass and silicon adsorb fluoride ions, therefore they are not the best choice. SU-8 is stable towards chemicals and solvents but nothing is known about its behaviour with radioactive fluoride. Here we develop a simple fabrication procedure to make fully coated SU-8 microreactors and we demonstrate the potentiality of SU-8 microfluidic architectures to be used for radiosynthesis, giving a proof of their low tendency to trap radioactive fluoride if compared with traditional glass microchannels.